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Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 38
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 40
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 41
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 42
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 43
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 44
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 45
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 46
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 47
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 48
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 49
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 50
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 51
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 52
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 53
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 54
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 55
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 56
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 57
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 58
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 59
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 60
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 61
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 62
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 63
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 64
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 65
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 66
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 67
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 68
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 69
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 70
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 71
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 72
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 73
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 74
Suggested Citation:"Characteristics of Doctorate Recipients." National Research Council. 1978. Century of Doctorates: Data Analyses of Growth and Change : U.S. PhD'S--Their Numbers, Origins, Characteristics, and the Institutions From Which They Come : a Report to the National Science Foundation, to the National Endowment for the Humanities, and to. Washington, DC: The National Academies Press. doi: 10.17226/18650.
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Page 75

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2 Characteristics of Doctorate Recipients In the first chapter, we were concerned with the numbers of PhD's, as they varied over time, by field, and by sex. We turn now to the charac- teristics of the doctorate recipients themselves— those characteristics that can be tabulated from the data of the DRF. These appear to be of pri- mary importance regarding the education and employment of these people—particularly to the educational institutions and to the agencies that provide support for graduate education. These characteristics, in the order in which they will be described, concern: 1. The educational background of the families from which they come. 2. Citizenship and racial/ethnic identifica- tion. 3. Age and the time lapse between baccalau- reate and doctorate degrees. 4. Master's degrees. 5. Field switching between the baccalaureate and doctorate levels. 6. Geographic migration, region by region within the United States, from high school to PhD. HIGHLIGHTS • Educational Background. The general popu- lation of the United States has become steadily better educated over the past century, at the rate of a little less than two grade levels per generation. The PhD's have come from families at the leading edge of this educational wave— from families that were, on the average, one generation ahead of the general population. There are significant sex differences: The women PhD's come from slightly better-educated families than do the male PhD's. Field differ- ences also exist but are decreasing in magnitude. The pattern of all of these changes makes a fas- cinating mosaic. • Citizenship. One in seven PhD's awarded in the United States is to a non-U.S. citizen. The proportion varies profoundly by field: for- eign citizenship is highest in male-dominated agricultural sciences (33 percent), engineering (28 percent), and medical sciences (21.5 per- cent) , and lowest in education (5.4 percent) and psychology (5.2 percent), in which the proportion of women is much higher. Thus the field differ- ences can be said to explain a large part of the overall sex differences: 15 percent of the male PhD's and 10 percent of the female PhD's are non- U.S. citizens. • Racial/Ethnic Identification. Data on racial/ethnic composition of the doctorate recip- ients has only recently become available. It varies by field, and hence, to some extent, by sex. Overall, including U.S. and foreign citizens but omitting those for whom racial/ethnic data are unavailable, 87.7 percent of recent PhD's are white, 3.4 percent are black, 0.5 percent are American Indians, 1 percent are Spanish Americans, Mexican Americans, or Chicanos, 0.2 percent are Puerto Ricans, and 7.2 percent are Orientals. Blacks and American Indians tend to be concen- trated in education, and Orientals in the EMP fields. • Age. The typical PhD is about 30 years old at graduation—younger in the sciences, older in the nonsciences, particularly education. Age at baccalaureate and age at doctorate tend to show the same pattern of field differences, but there

29 is less spread at the BA level. Age at PhD is therefore determined principally by time lapse between the baccalaureate and doctorate. BA-PhD time lapse has increased over the past half- century, but the major fluctuations were those induced by World War II and its interruption of the educational progress of both men and women, but particularly the men. • Waster's Degrees. Except in chemistry, most PhD's also have master's degrees. In chem- istry, 41 percent have the degree; in physics, 64 percent; in the biosciences and the medical sciences, 65 percent; in psychology, 77 percent; in the earth sciences, 78 percent; in mathematics, 79 percent; in the social sciences, 83 percent; in the professions, 86 percent; in the humani- ties, 87 percent; in engineering, 89 percent; in the agricultural sciences, 90 percent; and in education, 97 percent. The percentages are typically higher for women than for men, the ex- ceptions being the earth sciences, engineering, and agricultural sciences. • Fields at BA and PhD. Field switching, for the doctorate-bound population, results principally in flows from mathematics, physics, chemistry, engineering, the agricultural sciences, and the humanities to the biosciences, the earth sciences, and education. The other fields are in relatively close balance overall, but for the women there is a particularly strong movement out of the professions1 and the medical sciences.2 In this report each field is con- sidered in terms of its donor/receptor character- istics: the extent to which it "donates" its baccalaureate recipients to the various "receptor" fields at the doctoral level. • Interregional Migration. Most PhD's earn their doctorates in the same geographic regions in which they graduated from high school and from college. The regional shifts have varied over time and are a function of the relative strength of each region at the secondary, higher education, and graduate levels and population. Patterns of migration are explored in terms of "donor" and "receptor" regions, at the HS-PhD level and BA-PhD level. SOCIOECONOMIC BACKGROUNDS OF DOCTORATE RECIPIENTS Potentially, there are a number of indicators that could be used to describe the socioeconomic backgrounds of doctorate recipients. However, as a practical matter, the only indicator avail- able in the DRF is the level of education attained by the parents of the PhD's. Fortunately, this is an important indicator for this particular group, distinguished as it is from the general population primarily by its educational attainment. 'The professions include business administration, home eco- nomics, journalism, theology, law, social work, library science, and the speech and hearing sciences. The medical sciences include medicine and surgery, dentistry, veterinary medicine, hospital administration, parasitology, pathology, pharmacy, and pharmacology. It is of course to be expected that PhD's come mostly from the better-educated families. The extent of the difference in the educational spectrum from which PhD's come, as compared with the general population, was explored in Profiles of PhD's in the Sciences, published by the NAS in 1965. That study compared the educational levels of the general population with those of the parents of the PhD's who graduated over the period from 1935 to 1960. Because PhD's are, on the average, about 30 years old at the time they take the doctorate, and because their par- ents are, on the average, assumed to be about 30 years older than that, the time differential between the birth of the parents and the year in which the PhD's graduate is assumed to be 60 years. It is this time differential that was used to compare the PhD's and the general popula- tion in the 1965 study. UPDATE AND NORMATIVE FRAMEWORK It is now possible to update and extend the earlier study. A sample of 10,000 PhD's was used in the 1965 study, drawn from the graduation co- horts of 1935, 1940, 1945, 1950, 1955, and 1960. At the present time, complete data are available for the more recent graduates, here divided into four cohorts, the PhD's of 1963-1965, 1966-1968, 1969-1971, and 1972-1974. Census data from the decennial censuses for 1940-1970 provide informa- tion on the educational levels attained by the general population, typically divided into 10- year age cohorts. Educational level is recorded at nine steps of attainment: no formal education; grades 1-4; grades 5-7; grade 8; 1-3 years of high school; high school graduation; 1-3 years of college; college graduation; and postcollege training. In the tables and graphs to followr some discontinuities, showing up as jagged lines in percentile graphs of educational attainment, will be found. This is in part a result of the particular steps of attainment that were employed, but it is also due to the fact that, historically, generally accepted termination points of formal education have been eighth grade, high school graduation, and college graduation. In the case of the PhD's in the DRF, a slightly different set of educational attainment points was used (third grade instead of fourth; sixth grade instead of seventh; and an additional level at the top, differentiating master's degrees and the doctorate). However, the data sets are compatible, and meaningful comparisons are provided, using the assumption described above to define the birth cohorts of the parents of PhD's. In examining the graphs, particularly Figures 27 and 28, a slight truncation of the norm for the general population will be noted for the most recent cohort. This is because data were available in 1970 for persons age 25 and up, but some of them (more men than women) had not com- pleted their formal education at that time. The limitation is slight and does not interfere with the usefulness of the data, except for post- baccalaureate degrees.

30 TABLE 9 EDUCATIONAL ATTAINMENT OF THE UNITED STATES POPULATION, BY BIRTH COHORT AND SEX (Averaged Data from Censuses of 1940,1950, 1960, and 1970)* Educational Level Attained Year of Birth Males No education % Before 1866 1866-1875 1876-1885 1886-1895 1896-1905 1906-1915 1916-1925 1926-1935 1936-1940 10.13 10.13 8.28 8.28 6.73 6.73 5.40 5.40 2.79 2.79 1.46 1.46 1.02 1.02 0.95 0.95 0.91 0.91 Grades 1-4 t 18.63 28.76 18.48 26.76 16.44 23.37 14.29 19.69 9.75 6.33 3.85 4.87 2.49 3.44 1.52 2.43 C» 12.53 7.80 Grades 5-7 % 23.03 51.79 22.84 49.60 22.18 45.54 21.73 41.42 19.92 32.45 15.41 23.20 9.90 14.77 7.30 4.93 7.36 Ct 10.74 8th grade t Ct 33.00 84.79 30.18 79.78 29.69 75.23 28.11 69.53 26.48 58.92 19.74 42.95 12.60 27.36 8.79 19.52 5.95 13.31 High school, t 1-3 years C\ 4.80 89.59 6.72 86.49 8.91 11.53 15.94 74.86 20.25 63.20 21.19 48.55 19.74 39.26 17.90 31.12 84.13 81.06 High school t graduate C% 4.99 94.58 6.55 8.06 92.19 9.32 12.54 87.40 20.26 83.46 29.37 77.92 31.77 71.03 37.13 68.24 93.04 90.36 College, % 1-3 years Ct 2.53 3.22 3.62 4.74 95.12 6.08 93.47 7.96 10.05 87.97 11.50 82.53 13.44 81.69 97.11 96.26 95.81 91.42 College % graduate c% 2.01 99.12 2.52 2.88 98.69 3.14 98.26 3.84 97.32 4.31 95.73 6.20 94.16 8.67 91.20 8.64 90.33 98.78 Graduate/pro fes- t sional school Ct .87 1.22 100.00 1.31 100.00 1.73 100.00 2.69 4.26 5.83 8.80 100.00 9.67 100.00 100.00 100.00 100.00 100.00 Median 7.27 7.51 7.65 7.81 8.16 9.54 11.55 11.84 12.01 Mean 6.39 6.77 7.17 7.65 8.59 9.67 10.76 11.53 12.01 Females No education % Ct 9.44 9.44 6.91 6.91 5.87 5.87 5.19 5.19 2.62 2.62 1.23 1.23 0.82 0.82 0.86 0.86 0.81 0.81 Grades 1-4 t Ct 14.88 24.32 14.18 21.08 13.02 18.89 11.13 16.32 7.80 4.56 5.79 2.65 3.47 1.70 2.56 1.18 1.99 10.42 Grades 5-7 t ct 21.54 45.86 21.52 42.60 20.83 39.72 20.27 36.59 18.32 28.73 13.90 19.69 8.59 12.06 5.65 8.21 4.04 6.03 8th grade V 35.26 81.12 32.24 74.84 29.99 69.70 27.76 64.35 24.68 53.41 18.53 38.22 11.66 23.72 7.19 5.12 11.15 Ct 15.40 High school, % 1-3 years C% 6.34 87.46 8.78 83.62 11.43 81.13 13.75 78.10 17.11 75.52 21.13 21.93 45.65 21.90 37.30 20.22 31.37 59.35 High school t graduate C% 8.01 95.47 10.25 93.87 11.53 92.65 12.50 90.60 16.77 87.29 24.91 84.26 37.62 83.27 42.41 79.71 45.26 76.63 College, % 1-3 years C% 2.81 98.29 3.82 97.69 4.53 97.19 5.89 96.49 7.73 95.02 9.19 93.45 10.06 93.33 11.38 12.86 89.49 91.09 College % graduate Ct 1.50 99.79 1.98 99.66 2.32 2.62 99.11 3.56 4.03 97.48 4.42 97.74 5.89 96.99 7.29 99.50 98.58 96.78 Graduate/profes- * sional school Ct 0.21 0.36 100.00 0.51 100.00 0.89 100.00 1.42 100.00 2.52 2.27 100.00 3.02 100.00 3.22 100.00 100.00 100.00 Median 7.62 7.73 7.84 7.98 8.36 10.17 11.62 11.80 11.91 Mean 6.75 7.25 7.60 7.99 8.89 9.91 10.73 11.30 11.67 See text for censuses contributing to each average. ^C» • cumulative percent. The general population educational attainment data are shown in Table 9. The percentage com- pleting each level, and the cumulative percentage up to that level, is shown for each birth cohort, for men and for women. Additionally, means and medians, by cohort and sex, are given. The data on mean educational levels from this table are plotted in Figure 24, which also shows comparable data for the educational levels of the parents of PhD's, for the birth cohorts for which data are available. In the case of both the general population (shown as heavy lines) and the PhD population (shown as lighter lines), the data for males are given in solid lines and the data for females in dashed lines. It is apparent ^For those who may wish to compare the data of Table 9 with other sources, it should be noted that the columns of this table usually combine data from two or more censuses to obtain more stable percentages. This is particularly important at the extremes of the distributions, where data are sparse. The census data available were from rather small samples, rather than complete figures. The pre-1866 data were taken solely from the 1940 census; 1866-1875 and 1876-1885 data from the 1940 and 1950 censuses; 1886-1895 data from the 1940, 1950, and 1960 censuses; 1896-1905 and 1906-1915 data from the censuses of 1950, 1960, and 1970; 1916-1925 data from the censuses of 1960 and 1970; and the rest from the 1970 census alone.

31 13 r- Females, Age 25 and Up, U.S. General Population Males. Age 25 and Up, U.S. General Population 6 - The parents of PhD's have been about 30 years ahead of the general population, on the average, in educational level (average grade attainedl I I 1860 1870 1880 1890 1900 1910 1920 1930 1938 ASSUMED MEAN YEAR OF BIRTH FOR COHORT SOURCE: NRC, Commission on Human Resources FIGURE 24 Educational level of parents of U.S. native PhD's compared to U.S. general population, by year of birth. that over the 75 years shown here, there has been a steady progression of educational attainment. The trend for the two sexes is similar, but prior to 1920 the mean for women was higher than that for men, whereas the reverse is true for the more recent cohorts. PARENTS AND POPULATION NORMS The educational level- of the parents of PhD's is in marked contrast to that of the general popu- lation, as far as the means in Figure 24 are concerned. From the earliest cohort shown until the beginning of the twentieth century, the par- ents of native-born U.S. PhD's averaged just under high school graduation as their highest level of educational attainment."4 Meanwhile, ''Parents of U.S. natives only are included here, both because of the difficulty in equating educational levels across cul- tural lines and because of field and cohort differences in percentage of persons of foreign origins. Had they been in- cluded, some marked distortions would have been produced. the general population norm moved up from about the seventh grade to about the eighth grade. From the beginning of the present century, the average of parents of PhD's moved up approxi- mately parallel to the change in the general population norm. It is interesting to note that, prior to 1900, the mean educational level of the mothers of PhD's was below that of the fathers, but in the more recent cohorts the dif- ference in means has vanished. The difference in distribution of educational attainments has not vanished, as will be seen, thus illustrating a limitation of mean values to describe a popu- lation characteristic.

32 13 12 11 !» —i ui ui o tr 6 The U.S. mean educational level has increased steadily; the median jumped quickly after 1900, as "typical school leaving" responded to compulsory education laws I I I I 1860 1870 1880 1890 1900 1910 1920 1930 1938 YEAR OF BIRTH SOURCE: U.S. Decennial Censuses of 1940, 1950. 1960, and 1970 FIGURE 25 Changing educational level of U.S. population: means versus medians. A CHANGING EDUCATIONAL SPECTRUM The difference between means and medians may be noted in examining the data of Table 9. It is illustrated graphically in Figure 25 for the general population. Here we see again the pro- gression of means over the same period as shown in Figure 24. Median data are also shown and, by contrast to the means, show sharp changes during the first 20 years of the present century. The medians rise at a very modest rate until the beginning of the twentieth century, when they shoot up rapidly, then rise slowly after 1920. This is an effect due to the quite rapid change of the middle section of the population—a move

33 1876-1885 40 30 20 10 0 1,: LJ I 1 40 30 20 2 10 I. I I 40 30 20 10 0 1916 1925 o 1- 40 0 30 £ "• 20 10 0 40 30 20 10 0 1936-1940 40 30 20 10 0 0368 12 16 20 GRADE LEVEL 0368 12 16 20 GRADE LEVEL SOURCE NRC, Commission on Human RtsourcM, based on BurMu of Census data FIGURE 26 Distributions of educational attainment of general population age 25 and up, by birth cohort and sex. from a norm of eighth grade graduation to a norm of high school graduation. The median is af- fected by changes around the midpoint only, where- as the mean is affected by changes at any point in the educational scale. Figure 26 shows fre- quency diagrams of the percentage of the popula- tion, by sex, at each educational level recorded in the census statistics, for selected birth co- horts, from those born between 1876 and 1885 to those born between 1936 and 1940. The peaks of the distributions shift, in the first 2 de- cades of the twentieth century, from eighth grade to twelfth grade. In the 1936-1940 co- hort the grade level range has been extended by incorporation of data calculated from DRF to supplement the census data.

34 100 g 1 o o §- 5 o o 2 E O (9 60 O 40 I co 20 No Formal Education The "grade level mix" for the U.S. adult male pop- ulation has shifted strongly; tha norm now is high school graduation or beyond 1-3 Years of High School Some Postcollege Training J I I 1860 1880 1920 1900 BIRTH COHORT SOURCE: NRC, Commission on Human Resource, bawd on Bureau of Census data FIGURE 27 Changing educational spectrum of U.S. male population. 1938 GROWTH CURVES OF EDUCATIONAL ATTAINMENT A sex difference is visible in the frequency polygons of Figure 26 chiefly by way of a larger proportion of men who have gone to college. The changes over time in educational attainment are not as easy to see in Figure 26 as in the next graphs, which show time changes in the various levels of educational attainment. The proportion of the population which has had no formal educa- tion decreases, for both men and women, from about 10 percent to about 1 percent in Figures 27 and 28, which are taken from the data of Table 9. The proportion who are high school grad- uates, but who go no farther than high school, is shown as the shaded area in the center of the graph. For the men, this area increases gradually and rather regularly; for the women there is an al- most explosive growth after the beginning of the twentieth century. The shaded area near the bot- tom of the graph in both pictures indicates those who have completed baccalaureate degrees but no more. This is somewhat larger for men than for women, but it is the portion beyond the baccalau- reate that shows the greatest sex difference. In the most recent cohort (where data were incom-

35 100 High school graduation-hut no more-has tended to become the norm for U.S. women 1860 1880 1920 1900 BIRTH COHORT SOURCE: NRC, Commission on Human Resources, based on Bureau of Census data FIGURE 28 Changing educational spectrum of U.S. female population. 1938 plete in the 1970 census), the proportion of men is almost 10 percent; for women it is only slightly over 3 percent. The curves for all educational levels progress rather smoothly, with the exception of the very rapid shift in high school graduations after 1900. This is probably the effect of changes in the compulsory education laws. These state laws, enacted mostly during the last half of the nineteenth century, began to have a marked effect at the high school level in the beginning of the twen- tieth century. At that point most state laws required attendance only up until age fourteen; by 1920, age sixteen was a more typical school- leaving minimum. Because these state laws were not all enacted simultaneously, and because of inevitable lags in enforcement, the effects were not sudden—although as noted earlier, the ex- pansion of the women, high-school-graduate-only group is quite rapid, because a much smaller proportion of women than of men go on to college. sSee A. W. steinhilber and C. J. Sokolosky, state Law on Compulsory Attendance, Publication OE 23044, circular 793 (Washington, D.C.: USOE, 1966). (Superintendent of Documents Catalog FS 5.223:23044.)

36 0.5 1 18 PERCENT ABOVE INDICATED GRADE LEVEL 10 30 50 70 90 95 98 99 99.5 16 16 12 11 Q < K T T 1 I I i r T T T I I I College Graduation The spectrum of educational levels has shifted steadily for U.S. males, over periods for which census data are available 0 99.5 99 98 95 90 70 50 30 10 5 2 1 0.5 PERCENT BELOW INDICATED GRADE LEVEL (Note Normal Probability Spacing) SOURCE: NRC, Commission on Human Resources, based on Bureau of Census data FIGURE 29 Percentile graphs of educational levels attained by U.S. males age 25 and over, by decade of birth. PERCENTILE NORMS OF EDUCATIONAL ATTAINMENT Up to this point, we have considered means/ medians, frequency distributions, and growth curves of the educational levels of the general population. In order to put the data into a form that will facilitate comparison with the educational spectrum of the fathers of PhD's, Figure 27 has been recast into percentile terms, with one percentile curve for each birth cohort, in Figure 29. A similar set of curves could be drawn for the general population of women, as a normative frame for the mothers of PhD's. In both cases, the progression of the birth cohorts is seen as a march of the curves across the page from left to right. The curves for women (not shown because they are so similar as to be redun- dant) vary only in that smaller percentages achieve the higher levels of education, although at the elementary education levels, the percent- age of women at each grade level is slightly higher than that for men. The percentile data are plotted with normal probability spacing, which provides for equal intervals in terms of standard deviation units. This compresses the percentages around the middle of the distribution and expands the percentages at the extremes. In spite of this midrange compression, the greatest

37 0.5 1 PERCENT ABOVE INDICATED GRADE LEVEL 5 10 30 50 70 90 95 98 99 99.5 ui > Q < DC O f I -V~~ t I College Graduation Fathers of PhD's of 1969-1971 (Assumed Birth 1906-1915) High School Graduation U.S. Male Population Born 1906-1915 Equivalent birth cohorts of the general male population and the fathers of I'hD's are close together at the lower educational levels, diverge at higher levels 99.5 99 98 95 90 70 50 30 10 5 2 1 0.5 PERCENT BELOW INDICATED GRADE LEVEL (Note Normal Probability Spacing) SOURCE: NRC, Commission on Human Resources FIGURE 30 Educational attainment of fathers of PhD's, by birth cohort, compared with the norms of Figure 29. changes are shown at about this point between the eighth and twelfth grades. Because it is the upper educational levels that are the primary concern with respect to the parents of PhD's, this method of normal probability spacing per- mits a clearer view of the changes where they are most relevant to the present study. If the percentiles had been plotted as equal intervals, the result would have been a tight compression at both extremes of the distribution, minimizing the most relevant data. Figure 29 provides a normative frame for interpreting the data on the educational attain- ment spectrum for the fathers of PhD's. This is done in Figure 30, where a heavy black line has been used to represent the general population curve for the birth cohort of 1906-1915, and a dashed line to represent the fathers of PhD's who were their contemporaries—the fathers of the PhD's of 1969-1971. A similar comparison could be made for the mothers of PhD's of the same era, compared to the general population of women, but the data are too nearly redundant to justify a separate graph. In both cases, in spite of minor sex differences, one may say as a rough generalization that the parents of PhD's are about one generation ahead of the gen- eral population in educational attainment.

38 0.5 1 PERCENT ABOVE INDICATED GRADE LEVEL 10 30 50 70 90 95 98 99 99.5 Ul Q oc o I I I I I I I Fathers of PhD's of 1969-1971 (Assumed Birth 1906-1915) High School Graduation U.S. Female Population - Born 1906-1915 Mothers of Ph D's of 1969-1971 (Assumed Birth 1906-1915) U.S. Male Population Born 1906-1915 3 - 99.5 99 98 95 90 70 50 30 10 5 2 1 0.5 PERCENT BELOW INDICATED GRADE LEVEL (Note Normal Probability Spacing) SOURCE: NRC, Commission on Human Resources FIGURE 31 Comparison of educational attainment spectra of males and females in general population and parents of PhD's. SEX DIFFERENCES IN EDUCATIONAL ATTAINMENT To summarize the comparison of the data on parents of PhD's as compared to the general population, and to present data for both males and females, Figure 31 shows four percentile curves. The heavy lines are those for the gen- eral population, the lighter lines for the par- ents of PhD's, and, in both cases, solid lines represent data for men, dashed lines data for women. For both the general population and for parents of PhD's, there is a crossing-over of the men and women's graphs at the high school level. The difference, however, is greater for the par- ents of PhD's than it is for the general popula- tion. In both comparisons, the curve for men is above that for women at the higher education level but below at the elementary school level. The data for the various grade levels for fathers of PhD's are given in Table 10 and for mothers in Table 11. In both tables, data are given sepa- rately for the female PhD's and the male PhD's and for both combined. At the bottom of the table, the summary statistics are provided: means, standard deviations, and the percentile points 10, 25, 50, 75, and 90. The sex differ- ences here provide an interesting study and will be examined in more detail in the graphs to follow. The interesting new information shown here is that the progression of the cohorts con- tinues, for both the mothers and the fathers of the PhD's, for the recent cohorts. The mean data shown here are shown graphically in Figure 24. The data of Tables 10 and 11 show that the same progression given for the means holds also for the other portions of the educational spectrum.

TABLE 10 DISTRIBUTION OF EDUCATIONAL LEVELS OF FATHERS OF PhD's OF U.S. ORIGIN, BY COHORT AND SEX OF PhD ,*,f 1963-1965 PhD Year and Sex 1966-1968 1969-1971 1972-1974 Total , 1963-1974 <l O * * ? y ^ ' j f / . j 8 f *v f / 3 | / J r * t '£ 4 *i f £ NONE N VI 112 30 342 1.5 1.0 329 .1 41 .7 370 .7 .7 148 47 .5 395 .6 .6 285 64 .5 349 .9 .9 1274 .7 .7 182 1456 .5 .6 .5 .6 vk 1.5 1.0 .8 .1 .6 • 9 .1 .1 .9 .5 GRADES 1-3 N 490 1.6 2.6 60 990 1*1 672 77 ill 846 106 a 840 1.4 1.9 1 7(1 }•« 1010 1.4 1*9 B 413 3261 I'.? l^ 1:1 1:1 l:? 1.7 GRADES 4-6 GRADES 7-8 N VI 247 2608 10.1 6781 365 3307 6.7 8.9 3500 5.8 4019 5.7 666 3774 5.2 7.1 "H 1797 13708 5.3 6.0 7.0 8.0 vk 10^ i*2 lif 6.0 8.0 5.1 ?:! 4.7 6.4 N VI 6155 626 7539 17.3 26.4 916 8455 17.1 26.0 9515 15.7 23.5 1356 13.4 20.0 10871 15.4 23.0 8264 14.2 21.4 1591 9855 31473 16.3 24.7 4489 35962 13.1 15.8 20.1 23.8 vk 19.8 30.0 I?:* 15.0 23.0 H.S. 9-11 Vk 370 8:1 4777 iMo1 5388 10.9 36.9 6256 •84 7140 33". i 5771 9.9 31.3 1168 6939 9.6 30.3 20347 3033 23380 8.9 10.3 29.0 34.1 41*4 10.4 33.9 8.7 28.7 H.S. GRAOI12I N VI V3C 6399 784 20.7 55.9 9765 1182 19.4 52.4 10947 22.1 14830 24.5 58.4 1959 19.3 16789 23.8 56.9 14801 25.4 56.7 2939 20.7 46.5 17740 24.5 54.8 45795 23.7 6864 52659 20.1 23.1 49.1 57.2 20.6 62.0 6l".l 11:1 59.0 48.0 58.9 COL. 1-3(13-15) H VI 3775 12.1 74.1 512 4287 5649 13.0 72.9 845 13.9 6494 13.1 72.1 8184 13.5 71.9 1504 14.8 62.8 9688 13.7 70.6 8154 2073 14.6 61.1 10227 14.1 68.9 25762 13.3 72.2 4934 30696 14.4 13.5 63.5 70.7 vk 13.5 69.4 12.3 73.6 66.3 14.0 70.7 COL GRAO (16) N 4395 14.1 88.2 608 16.0 85.4 5003 14.3 87.9 6392 14.7 87.6 1128 7520 8984 14.9 86.8 1941 19.1 81.9 10925 86'.? 8894 15.2 85.9 2772 19.5 HO. 6 11666 16.1 85.0 28665 14.8 87.0 6449 35114 18.8 15.4 82.3 86.1 vie 18.5 84.8 HA, ETC. (17-180 II VI 396 10.5 95.9 3024 •Zii 632 4545 5666 9.4 96.2 11!? *?!,. 5884 1903 13.4 94.0 7787 10.7 95.7 18091 9.4 96.4 4219 22310 12.3 9.8 94.6 95.9 vk 96^ 8.7 96.6 94.6 96.0 10.1 96.0 PHO.P-OOC (20> N VI 1037 3.3 100.0 196 1193 3.4 1502 3.5 100.1 294 1796 3.6 100.1 2290 3.8 946 2836 4.0 100.0 2355 4.0 100.0 841 3196 4.4 100.1 7184 3.7 100.1 1837 9021 5.4 4.0 100.0 99.9 vk 4.1 100.0 100.0 4.8 100.0 100.0 5.4 100.0 5.9 99.9 TOTAL KNOWN H VI Vz 31095 3789 100. 0 94.9 100.0 34884 100.0 96.0 100.0 43480 100. 1 96.9 100.1 6091 100.0 95.6 100.0 49571 100.1 96.7 100.1 60419 10150 100.0 94.4 100.0 70569 100.0 95.2 100.0 58356 100.0 92.7 100.0 14187 99.9 92.1 99.9 72543 193350 100.1 95.0 100.1 34217227567 100.0 99.9 93.7 94.8 100. 0 99.9 100.0 96.2 100.0 100.0 !§i:s vk 100:5 100.1 UNKNOWN N V2 li?S I?? l*?o I3.ll 2a2 13?3 2992 4.7 947 9.6 3589 4.8 *fil !?.1! *7?4 "Hi "?3 "??! GRAND TOTAL N V2 32333 100.0 3992 100.0 36325 44892 100.0 6373 100.0 51265 100.0 63411 100.0 10747 100.0 74158 100.0 62985 103.0 15399 100.0 78384 100.0 203621 100.0 36511240132 100. 0 100.0 100.0 MEAN 11.61 12.17 11.67 • 11.90 12.47 11.97 » 12.15 12.90 12.26 • 12.36 13.11 12.50 • 12.07 12.83 12.18 STO. OEV. 4.30 4.31 4.30 » 4.21 4.26 4.22 • 4.10 4.17 4.12 * 4.06 4.13 4.09 • 4.16 4.20 4.17 10 PCTILE 6.43 6.63 6.44 • 6.61 6.78 6.63 * 6.78 7.01 6.81 * 6.89 7.15 6.93 * 6.71 6.96 6.74 25 PCTILE 8.00 8.45 8.04 • 8.34 9.11 B.3S • 8.93 10.23 9.09 * 9.59 11.21 9.86 * 8.62 10.16 8.82 50 PCTILE 11.92 12.22 11.95 • 12.06 12.38 12.10 • 12.16 12.91 12.21 • 12.24 13.22 12.31 • 12.13 12.70 12.19 75 PCTILE 15.57 15.85 15.60 * 15.65 15.97 15.70 * 15.70 16.14 15.78 * 15.79 16.21 15.89 • 15.70 16.11 15.77 90 PCTILE 16.92 17.37 16.98 • 17.05 17.50 17.11 • 17.18 17.77 17.29 • 17.32 17.89 17.46 • 17.16 17.75 17.27 N = number of cases; VI = vertical percentage on known total; V3C = cumulative percentage; V2 » percent of grand total. SOURCE: NEC, Commission on Human Resources.

40 TABLE 11 DISTRIBUTION OF EDUCATIONAL LEVELS OF MOTHERS OF PhD's OF U.S. ORIGIN, BY COHORT AND SEX OF PhD PhD Year and Sex / 1963-1965 1966-1968 1969-1971 1972- 1974 Total, 1963-1974 o ? / / J / / • / ? / ,' f / f 4 • *' i 4 NONE N VI 266 24 "?, 261 .6 .6 11 313 224 34 2S8 202 • • \jt *+o 252 953 160 1113 vie .9 .9 .6 .6 14 • 3 GRADES 1-3 N VI 240 .8 1.7 30 .8 1.4 270 303 .7 1.3 32 .5 1.4 335 .7 1.3 323 .5 .9 62 .6 .9 385 .5 .9 "I 68 .5 .9 389 .5 .8 1187 lit 192 •» 1.1 1379 vie .6 1.6 GRADES 4-6 N 1299 117 B 1547 3.6 4.9 ill 1887 !:! 1*2 1976 2.7 3.5 6366 3.3 4.4 999 2.9 7365 3.2 4.3 vie 4! 9 4".0 Ko 3:6 3.3 4.0 GRADES 7-8 N VI 566 14.9 20.4 5417 15.6 21.4 5792 768 12.6 17.7 6560 I?!? io°?f 8046 11.4 15.4 5860 10.0 13.6 1198 8.4 11.7 7058 9.7 13.2 23521 12.2 16.6 3560 10.4 14.4 27081 vie 21^ 13.4 18.3 13.3 18.2 15.6 13.7 H.S. 9-11 N VI 3645 11.8 33.4 422 11. I 4067 11.7 33.1 4966 11.5 29.8 646 10.6 28.3 5612 6294 1008 9.9 23.6 7302 10.3 25.7 5553 1266 6819 20458 3342 9.7 24.1 23800 vie 31.5 11.3 29.5 10.4 26.0 23.1 20.6 22.6 10.6 27.2 H.S. GPAOU2I 9817 1025 10842 31.3 64.4 14741 34.0 63.8 1671 16412 33.2 62.7 22034 36.4 62.4 2887 28.4 52.0 24921 35.3 61.0 22236 38.1 61.2 4340 26626 68878 62^ 9923 28.9 53.0 78801 34.6 61.3 vie a:$ 27.0 58.5 27.4 55.7 1?:? It:! COL. 1-31 13-151 vie z:t 761 |!:! 7737 1255 8992 18.2 80.9 10766 2189 12955 10604 18.1 79.3 2923 20.5 71.6 34602 17.9 7128 41730 83.0 17.8 81.6 20.6 76.3 77:8 80.8 20.8 73.8 COL GRAD (16) N VI 4037 13.1 96.1 589 15.5 94.1 4626 6028 1024 16.8 93.1 7052 14.3 95.2 8625 14.3 94.5 1851 18.2 91.7 10476 14.8 94.1 8566 14.6 93.9 2695 18.9 90.5 11261 15.5 93.3 27256 14.1 94.9 6159 33415 vie 13.3 95.8 18.0 91.8 14.7 94.3 MA, ETC. (17-18) N 1134 3.7 99.8 198 1332 3.8 99.6 1874 4.3 99.8 388 6.4 99.5 2262 3060 5.1 99.6 744 3804 5.4 99.5 3222 5.5 99.4 1239 8.7 99.2 4461 6.1 99.4 9290 4.8 99.7 2569 7.5 99.3 11859 5.2 99.5 VI ,1:! 4.6 99.8 7.3 99.0 vie PHD.P-DOC (20) N VI 11 102 11} 191 .3 223 92 315 234 125 359 278 933 vie .3 100.1 100^ 100^ 100.1 .4 .9 99.9 99:9 100:i 99:! 100^ 99.8 100.0 TOTAL KNOWN N VI V2 30867 100^ 3791 34658 99.9 95.4 99.9 43364 100.1 96.6 100.1 49466 100.1 96.5 100.1 60454 100.0 95.3 100.0 10170 99.9 94.6 99.9 70624 99.9 95.2 99.9 14247 72728 193166 34310227476 100.1 99.9 94.0 94.7 100.1 99.9 V3C 99.8 95.0 99.8 95^ 100.2 92:8 99.8 100.1 92.5 100.1 99.9 92.8 99.9 100.0 94.9 100.0 UNKNOWN GRAND TOTAL N V2 1466 4.5 201 1667 4.6 1528 3.4 isS Tf Iffl 2957 977 3534 4504 7.2 5656 7.2 10455 5.1 2201 6.0 ,2656 5.0 N 3o2o3.3o3 3992 100.0 3§o32o5 44892 100.0 63411 100.0 10747 100.0 74158 100.0 62985 100.0 15399 78384 100.0 36511; 100.0 100.0 MEAN 11.68 12.01 11.72 • 11.95 12.30 11.99 * 12.19 12.69 12.26 » 12.35 12.90 12.46 * 12.10 12.63 12.18 STO. DEV. 3.42 3.52 3.44 * 3.30 3.51 3.33 • 3.18 3.31 3.20 • 3.11 3.23 3.14 » 3.23 3.35 3.26 10 PCTILE 7.03 7.09 7.04 * 7.27 7.29 7.27 » 7.53 7.76 7.56 » 7.76 8.11 7.82 » 7.42 7.67 7.45 25 PCTILE 9.37 9.71 9.41 • 10.27 10.59 10.31 » 11.20 11.55 11.30 » 11.55 11.65 11.56 * 10.89 11.53 11.01 SO PCTILE 12.02 12.18 12.04 * 12.10 12.30 12.12 * 12.16 12.43 12.19 » 12.20 12.47 12.25 * 12.14 12.40 12.17 75 PCTILE 14.16 14.94 14.25 ' 14.41 15.33 14.53 * 14.61 15.58 14.79 * 14.76 15.68 15.03 * 14. S4 15.57 14.73 90 PCTILE 16.04 16.22 16.06 * 16.11 16.32 16.14 * 16.18 16.40 16.22 » 16.22 16.48 16.28 * 16.16 16.41 16.20 N = number of cases; VI - vertical percentage on known total; V3C - cumulative percentage; V2 = percent of grand total. SOURCE: NRC, Commission on Human Resources.

41 TABLE 12 MEAN EDUCATIONAL LEVEL OF FATHERS AND MOTHERS OF U.S. NATIVE PhD's, BY COHORT AND FIELD 1935-1960 Cohorts from Career Patterns Studies 1935 1940 1945 1950 1955 1960 Mother Father Mother Father Mother Father Mother Father Mother Father Mother Father Mathematics Physical sciences Engineering EMP TOTAL 10.60 11.45 10.63 12.16 11.44 11.86 10.68 11.45 9.88 11.10 10.72 11.71 11.58 10.24 11.34 12.56 12.38 10.97 12.12 10.67 11.84 11.26 11.57 11.13 12.21 11.57 11.93 11.67 11.57 11.21 11.47 11.58 11.63 12.22 11.80 11.68 12.08 12.04 12.19 11.16 10.95 11.73 11.79 10.72 11.23 11.97 10.33 11.55 Biosciences Agricultural sciences Medical sciences LIFE SCIENCE TOTAL 10.54 10.41 11.14 10.55 10.69 9.34 10.57 10.14 10.90 10.53 11.29 9.91 12.38 11.18 10.38 10.94 11.71 10.52 10.61 10.89 11.26 12.26 11.03 11.26 10.37 13.32 11.12 10.69 10.48 11.07 10.70 11.01 10.49 11.67 10.99 11.42 11.57 10.68 10.49 11.29 11.72 11.27 11.37 13.01 10.66 10.26 12.50 10.64 Psychology Economics Other social sciences BEHAVIORAL SCIENCE TOTAL 10.83 11.19 11.15 11.07 12.22 12.47 12.22 12.26 11.44 11.21 11.32 11.32 13.05 11.64 12.04 12.16 11.43 10.79 11.44 11.65 11.41 10.42 10.22 10.81 10.58 10.63 10.86 11.29 11.01 10.75 10.92 11.07 10.92 10.83 10.64 11.10 10.91 11.42 11.85 11.09 11.85 11.40 11.67 11.35 11.77 11.88 10.83 11.18 HUMANITIES AND PROFESSIONS 10.72 11.22 10.57 11.11 10.81 11.20 11.24 12.07 11.45 11.80 11.58 11.69 EDUCATION 9.33 10.45 9.27 9.55 9.39 9.93 9.90 9.36 10.63 10.29 10.48 10.39 GRAND TOTAL Males Females Total 10.74 11.37 10.56 12.26 10.75 11.09 13.33 11.34 10.62 11.49 10.80 10.96 12.24 11.21 11.03 10.79 11.01 11.21 12.41 11.32 11.05 11.51 11.17 12.05 11.25 11.34 11.52 11.86 11.75 11.39 11.54 11.17 10.81 11.84 11.44 11.09 1963-1974 Cohorts from DRF 1963-1965 1966-1968 1969-1971 1972-1974 Total 1963-1974 Mother Father Mother Father Mother Father Mother Father Mother Father Mathematics Physical sciences 12.32 12.13 12.56 12.27 12.90 12.50 13.09 12.97 12.61 13.31 13.08 12.82 13.40 13.10 12.88 12.54 13.16 12.73 12.64 12.79 Engineering EMP TOTAL 12.06 12.13 11.97 12.10 12.10 12.38 12.58 12.41 12.73 12.59 12.79 12.77 12.30 12.51 12.34 12.66 13.21 12.41 12.51 13.04 Biosciences Agricultural sciences Medical sciences LIFE SCIENCE TOTAL 11.99 11.95 10.59 11.48 11.64 12.20 11.69 11.84 12.08 12.31 11.01 11.99 12.07 12.64 11.92 12.18 12.47 12.82 12.93 12.20 12.44 12.75 13.15 12.53 12.87 12.08 12.37 12.67 11.20 12.11 12.36 11.40 11.47 11.82 11.24 12.16 12.47 11.65 12.44 12.82 Psychology Economics 11.69 11.89 11.76 11.75 11.81 11.66 11.76 11.77 12.08 12.33 12.28 12.20 12.28 12.16 12.41 12.30 12.58 12.80 12.67 12.64 12.81 12.96 12.79 12.82 12.75 13.02 13.28 12.99 12.41 12.59 12.57 12.50 12.63 12.63 12.68 12.65 BEHAVIORAL SCIENCE TOTAL 13.00 12.85 12.82 13.04 HUMANITIES AND PROFESSIONS 12.01 12.13 12.27 12.39 12.62 12.83 12.91 13.19 12.56 12.75 EDUCATION 10.71 10.38 10.92 10.49 11.26 10.82 11.50 11.11 11.21 10.81 GRAND TOTAL Males Females Total 11.68 12.01 11.72 11.61 12.17 11.67 11.95 12.30 11.99 11.90 12.47 11.97 12.19 12.69 12.26 12.15 12.90 12.26 12.35 12.90 12.46 12.36 13.11 12.10 12.63 12.18 12.07 12.83 12.18 12.50 Numbers small; means unreliable. SOURCE: NRC, Commission on Human Resources. FIELD DIFFERENCES In the tables and graphs above, we have examined the data for all fields of PhD's combined—as if they were a homogeneous set. However, there are marked differences between the fields, as shown in Table 12 and in Figures 32 and 33. Table 12 provides data on the mean educational level of the fathers and mothers of the PhD's, by field, with summaries into general field groups. Figure 32 shows the data on fathers' education for a set of these fields; Figure 33 shows corresponding data with respect to the educational levels of the mothers. The general average of all fields is shown for reference, as a heavy line in each figure. These average lines are the same as those shown earlier in Figure 24, but here the chart has an expanded

42 13 i- Although the growth trends in mean educational levels of fathers of PhD's crisscross, some field differentials remain typical, over the past 40 years I I I J— 1935 1940 1945 1950 1955 1960 1964 1967 1970 1973 YEAR OF GRADUATION SOURCE: NRC, Commission on Human Resources FIGURE 32 Field differences in educational level of fathers of PhD's. scale, since only the parents of PhD's, and not the general population, are involved. Although the field differences are pronounced, it is of interest to note that the lines for the several field groups show a marked conver- gence over time, with respect to both fathers' and mothers' education. This narrowing of dif- ferences between fields is true also of differ- ences within fields. An exception to the convergence of field lines is that for education. Both the fathers and the mothers of those who attain doctorates in education are at a much lower educational level than the parents of doctorate recipients in the sciences and humanities. Within the science fields, the parents of life scientists in the early cohorts were on the average less well educated than the parents of other scien- tists. This difference has greatly diminished in the more recent cohorts, probably reflecting the effects of urbanization. Many life scien- tists in the 'iarly years came from rural fami- lies: this differential is undoubtedly decreasing as a smaller and smaller proportion of the population lives on farms. The decreasing differential may also represent the effects of changes within the bioscience fields—the in- creased emphasis on analytic methods as compared with the earlier primarily descriptive science. It is interesting to compare the differences

43 13 12 ui K O Z 11 LU ft E 111 I 10 For the mothers of PhD's. the mean educational levels by field are not as diverse as for the fathers of PhD's. nor are the trends as chaotic Education 9 1935 I I I I I I I 1940 1945 1950 1955 1960 1964 1967 1970 1973 YEAR OF GRADUATION SOURCE: NRC. Commission on Human Resources FIGURE 33 Field differences in educational level of mothers of PhD's. shown here with the differences between fields shown by earlier studies6'7 of the high school backgrounds of doctorate recipients. In those studies, data were secured from the high schools from which the PhD's graduated, with respect to their grades and their scores on standardized tests of academic aptitude. The general hierar- chy of fields that was found there was similar to that shown in the current data. Another similarity to the present data concerned the 6L. R. Harmon, High school backgrounds of science doctorates, Science 133(3454):679-788. 7L. R. Harmon, High school ability patterns, a backward look from the doctorate, in Scientific Manpower Report 6 (Washington, D.C.: NAS/NRC, August 20, 1965). ability levels of the male PhD's as compared to the females. Across all fields taken together, and within each of the fields separately, the women PhD's in the earlier studies showed higher academic ability than the male PhD's at the high school level, in terms of both grades and intel- ligence test scores. For more detail, see the reports referenced above. The general thrust of those findings is similar to the differences shown in Tables 10 and 11. More detailed data, showing mean educational levels for the fathers and mothers of men and women PhD's separately, are provided in Table 13, by field and cohort, with field summaries and summary data also for the entire 1963-1974 period.

44 TABLE 13 EDUCATIONAL LEVEL OF FATHERS AND MOTHERS OF NATIVE U.S. PhD's, BY SEX. FIELD, AND COHORT Field and Sex of Doctorate Recipient Cohort 1963-1965 Cohort 1966-1968 Cohort 1969 -1971 Cohort 1972-1974 Total 1963-1974 Mathematics Father Mother Father Mother Father Mother Father Mother Father Mother Male 12.51 12.29 13.06 12.87 13.24 12. 92 13.34 13.04 13.10 12.84 Female 13.42 12.88 13.68 13.47 14.26 13. 66 13.98 13.41 13.94 13.43 Physical sciences Male 12.26 12.11 12.62 12.47 12.74 12. 58 13.06 12.78 12.69 12.51 Female 12.79 12.53 13.31 13.20 13.75 13. 29 13.72 13.36 13.51 13.19 Engineering Male 11.97 12.05 12.09 12.10 12.40 12. 37 12.76 12.59 12.33 12.30 Female — — — — 13.11 12. 72 13.99 12.87 13.94 13.01 TOTAL EMP Male 12.19 12.11 12.49 12.39 12.69 12. 55 13.00 12.76 12.62 12.48 Female 12.99 12.67 13.44 13.27 13.86 13. 37 13.81 13.35 13.64 13.25 Biosciences Male 11.83 11.91 12.18 12.11 12.64 12. 53 12.99 12.81 12.50 12.42 Female 12.81 12.54 12.99 12.62 13.74 13. 21 13.77 13.40 13.48 13.07 Agricultural sciences Male 10.58 11.39 11.00 11.69 11.22 11. 90 11.58 12.15 11.17 11.84 Female — — — — 12.55 13. 02 13.53 13.62 13.07 13.31 Medical sciences Male 11.36 11.38 11.94 11.75 12.10 12. 10 12.35 12.48 12.02 12.02 Female 12.75 12.32 12.44 12.57 12.53 12. 71 12.81 12.30 12.66 12.47 TOTAL LIFE SCIENCES Male 11.51 11.74 11.94 12.00 12.30 12. 36 12.64 12.64 12.19 12.26 Female 12.79 12.52 12.94 12.62 13.60 13. IS 13.64 13.27 13.39 13.02 Psychology Male 11.65 11.61 12.02 11.92 12.59 12. 41 12.77 12.56 12.38 12.23 Female 12.51 12.06 13.27 12.70 13.49 13. 11 13.64 13.21 13.41 12.96 Economics Male 11.59 11.86 12.11 12.32 12.89 12. 77 13.16 12.90 12.54 12.53 Female 13.18 12.45 13.15 12.56 13.74 13. 15 14.51 13.92 13.87 13.27 Other social sciences Male 11.71 11.72 12.31 12.23 12.66 12. 58 12.78 12.69 12.52 12.45 Female 12.18 12.12 13.04 12.57 13.54 13. 14 13.77 13.44 13.47 13.12 TOTAL BEHAVIORAL SCIENCES Male 11.65 11.70 12.14 12.11 12.67 12. 54 12.83 12.67 12.46 12.37 Female 12.47 12.10 13.19 12.65 13.52 13. 12 13.74 13.33 13.45 13.03 Foreign literature and languages Male 11.79 11.63 11.96 12.01 12.52 12. 13 12.55 12.39 12.29 12.11 Female 12.39 12.03 13.13 12.75 14.04 13. 31 14.43 13.65 13.89 13.24 Other humanities Male 12.05 11.98 12.27 12.18 12.63 12. 52 12.95 12.75 12.55 12.43 Female 12.72 12.45 13.05 12.72 13.39 13. 08 13.80 13.35 13.43 13.06 Professions Male 11.59 11.66 11.84 11.85 12.08 12. 07 12.00 12.15 11.93 11.99 Female 12.01 11.85 11.76 12.03 12.18 12. 12 12.54 12.76 12.22 12.31 Education Male 10.19 10.56 10.33 10.81 10.62 11. 12 10.85 11.30 10.58 11.05 Female 11.21 11.36 11.17 11.38 11.62 11. 82 11.87 12.06 11.61 11.80 TOTAL NONSCIENCES Male 11.06 11.22 11.22 11.44 11.45 11. 68 11.67 11.87 11.42 11.62 Female 11.81 11.78 11.97 11.96 12.39 12. 35 12.71 12.62 12.39 12.33 GRAND TOTAL Male 11.61 11.68 11.90 11.95 12.15 12. 19 12.36 12.35 12.07 12. 10 Female 12.17 12.01 12.47 12.30 12.90 12. 69 13.11 12.90 12.83 12.63 SOURCE: NRC, Commission on Human Resources.

46 13.0 12.5 Q cr (J 12.0 11.5 The pattern stays relatively constant through four PhD cohorts; the important differences relate to the female PhD's Fathers of Male PhD's —L ± 1963-1965 1966-1968 1969-1971 YEAR SOURCE: NRC, Commission on Human Resources 1972-1974 FIGURE 34 A tetrad pattern: Educational level of fathers and mothers of male and female PhD'5 (U.S. native PhD's only, 1963-1974). TETRAD PATTERNS Figure 34 illustrates the pattern of mean educa- tional levels of parents of PhD's, that is, of fathers and mothers of male and female PhD's; hence the brief term "tetrad patterns." The overall pattern, for all fields combined, is rather constant across the four cohorts illus- trated, but it is definitely not the character- istic pattern for each field separately. The bottom two lines of Table 13 provide the data for Figure 34. Examination of the other rows quickly shows the importance of controlling for field, because of field differences. If one considers the rank order of the means for the four parental groups as defining the tetrad patterns, there are three distinct patterns, as well as some that are mixed or less distinct. These patterns, shown in Table 13 for the sev- eral fields, are described below. The most frequent tetrad pattern is that illustrated by the set of four means in the top left corner of Table 13—those for mathe- matics in the 1963-1965 cohort. Beginning with the highest educational level and proceed- ing downward, we have, in rank order: (1) fa- thers of women PhD's, (2) mothers of women, (3) fathers of men, and (4) mothers of men. This will be termed tetrad pattern A. Examina- tion of the rest of the table shows that pattern A characterizes all of the EMP fields in all cohorts, psychology and "other humanities" in all cohorts, and the biosciences, the "other social sciences," and the behavioral science total in all but the earliest cohort. It is clearly the dominant tetrad pattern in Table 13. A contrasting pattern, here termed pattern Z, characterizes the field of education in all co- horts and is found also in agricultural sciences, where data are available only for two cohorts, and in the professions for the 1972-1974 cohort and the total. In tetrad pattern Z, the order of educational levels is (1) mothers of women, (2) fathers of women, (3) mothers of men, and (4) fathers of men. A third pattern is found chiefly in the field group totals, and in the grand total, and is hence designated pattern T. It is the pattern illustrated in Figure 34: (1) fathers of women, (2) mothers of women, (3) mothers of men, and (4) fathers of men. It is clearly the resultant of the mixture of widely varying patterns, since it is seldom character- istic of individual fields, being found only in cohort 1963-1965 in the biosciences, medical sciences, "other social sciences," and in co- horts 1963-1965 and 1966-1968 in economics and the professions. As noted above, it does typify a number of the field group totals. Other pat- terns, perhaps random ones determined by the small numbers of cases, are found in the medical sciences. The patterns are intriguing and cause one to reflect on the pattern of parents' educa- tion as a determining factor in the eventual attainment of a doctorate degree—and perhaps as an influencing factor too on the field in which the degree is earned. The relation of pattern of grades in high school to later field of doc- torate was also examined—and with interesting results—in the high school backgrounds study.8 "ibid.

46 TABLE 14 PROPORTION OF POPULATION HOLDING ADVANCED DEGREES, BY COHORT AND SEX Masters and Professional Degrees PhD Degrees Granted in the Decade Cohort From Census Of Sex Population Age 25 And Up Per Million Population Age 25 And Up Birth Years Number Percent Corresponding PhD Years Number1' (from DRF) 1886- 1895$ 1940 M 7,962,019 107,941 1.36 1916-1925 6,527 820 F 7,550,052 46,224 0.61 1,189 157 Total 15,512,071 154,165 0.99 7,716 497 1896-1905 1940 M 9,164,794 156,938 1.71 1926-1935 17,922 1,956 F 9,168,426 83,720 0.91 3,114 340 Total 18,333,220 227,308 1.24 21,037 1,147 1906-1915 1940 M F Total 10,520,974 10,818,052 21,339,026 216,152 86,040 302,216 2.055 1936-1945 23,553 3,974 27,503 2,239 367 0.80s 1.42s 1,289 1916-1925 1960 M 11,757,900 590,594 5.02 1946-1955 55,542 4,724 F 12,336,433 224,778 1.83 6,304 420 Total 24,094,333 815,372 3.38 61,874 2,568 1926-1935 1970 M 11,273,090 890,602 7.90 1956-1965 101,442 8,999 F 11,865,637 345,966 2.91 12,269 1,034 Total 23,138,727 1,236,060 5.34 113,713 4,983 1936-1945 1970 M 12,162,643 926,285 7.61s 1966-1975 243,324 20,005 F Total 12,676,202 400,401 1,326,686 3.16S 5.349 (1975 estimated) 46,586 3,675 11,670 24,838,845 289,873 The 1950 census provided no data on postcollege degrees. Where a later census provided larger figures, for either population or degree holders, the later and larger figure was used. '''PhD data were from the DRF, supplemented by USOE data for 1916-1919 (sex breakout estimated) and an estimate for 1975, for which complete data were unavailable. *Data for birth cohorts prior to 1886 were deemed too inaccurate for use because of deaths by 1940, the earliest date for which postcollege degree data were available. 'The data for these years in the census indicated are probably underestimates by 50-75 percent for the graduate degrees other than the PhD. Differences of this magnitude appeared with successive censuses (1960 vs. 1970) for the same cohorts, where the cohorts were under age 35 at the time of the census. SOURCE: NRC, Commission on Human Resources, based on Census, USOE, and Commission on Human Resources data. POPULATION WITH ADVANCED DEGREES Time and space does not permit following out the implications of these patterns of parental educa- tion to a definitive conclusion, but one addi- tional set of data is available: The proportion of the population, by birth cohort, which holds advanced degrees, is shown in Table 14. This table combines data from two sources—the U.S. census and the DRF. The census provided data for numbers of persons with education beyond the baccalaureate, and the DRF provided data on the number of PhD's. By subtraction, the number of degrees at the master's and professional level was derived and expressed in terms of percentage of the cohort, by sex, holding such degrees. Because of the lesser frequency of doctorate degrees, the numbers were expressed in terms of PhD's per million in the population age 25 and up, also by birth cohort. The data from the censuses are truncated in the case of the youngest cohort from each census, since many persons who would eventually attain postbaccalaureate degrees had not yet attained them. By comparison of cohorts that appeared in two censuses, one 10 years later than the other, it was possible to estimate roughly the extent of such truncation. The extent is noted in the footnotes to Table 14 and is to be taken as a rough indication only. It is worthy of consider- ation, however, that a great number of master's degrees are earned in the field of education, where it is typically a prolonged process, so that many such degrees are earned when the stu- dent is in middle and late 30's; the doctorate is earned more typically at about age 40. Can the educational level of the parents be used to account for the proportion of any genera- tion going on to graduate school and eventual doctorates? Probably much more information than is provided here is needed to answer the question. All the growth curves—master's/professional and doctorate, separately by sex and with the sexes combined—show a constant upward trend in the data shown here. There does not appear to be any intergenerational point at which one can say that aspiration to the doctorate is triggered, but rather there seems to be a regular tendency for a higher proportion of the children to seek further education as the educational level of the parents rises. As noted earlier, the time lag of the general educational level of the population

47 TABLE 15 PERCENTAGE OF NON-U.S. CITIZENS AMONG U.S. PhD's, 1960-1974, BY FIELD AND COHORT Hen Women Both Sexes Combined 1960-1964 1965-1969 1970-1974 Total 1960-1964 1965-1969 1970-1974 Total 1960-1964 1965-1969 1970-1974 Total Mathematics 16.3 15.0 20.4 17.8 15.0 21.1 21.0 20.2 16.2 15.3 20.4 17.9 Physics 14.3 15.3 21.2 17.6 29.6 29.3 40.8 35.9 14.5 15.6 21.9 18.1 Chemistry 12.1 13.1 17.0 14.4 21.6 24.9 29.4 26.5 12.6 13.9 18.2 15.3 Earth sciences 16.0 18.4 20.5 18.8 16.7 20.4 16.7 17.8 16.0 18.5 20.3 18.7 Engineering 21.4 23.7 34.0 28.0 58.1 43.8 45.8 47.1 21.6 23.8 34.1 28.1 EMP TOTAL 16.3 18.2 25.2 20.9 22.7 25.3 29.2 27.0 16.5 18.4 25.4 21.1 Agricultural sciences 25.9 32.0 36.0 32.6 67.7 61.4 51.6 55.5 26.5 32.5 36.6 33.1 Medical sciences 19.3 22.2 22.6 21.9 23.9 22.6 16.9 19.1 19.7 22.3 21.6 21.5 Biosciences 16.8 16.7 15.4 16.1 15.6 15.2 14.3 14.8 16.7 16.4 15.2 15.9 LIFE SCIENCE TOTAL 19.4 20.7 21.1 20.6 17.9 17.1 16.4 16.8 19.2 20.2 20.4 20.1 Psychology 4.7 4.5 5.2 4.8 6.2 6.2 6.2 6.2 4.9 4.9 5.4 5.2 Social sciences 18.6 19.9 19.4 19.4 12.3 11.3 11.8 11.7 18.1 19.0 18.2 18.4 BEHAVIORAL SCI- ENCE TOTAL 12.7 13.8 14.0 13.7 8.3 8.2 8.6 8.4 12.1 12.9 12.9 12.8 SCIENCE TOTAL 16.2 17.8 21.3 19.1 14.5 14.9 14.7 14.7 16.1 17.6 20.5 18.7 Humanities 5.8 8.0 8.9 8.0 6.7 8.4 9.1 8.6 6.0 8.1 8.9 8.1 Professions 12.3 14.0 15.6 14.5 15.1 15.6 10.1 12.6 12.7 14.2 14.9 14.3 Education 5.0 4.9 5.8 5.4 6.3 6.1 5.0 5.5 5.2 5.2 5.6 5.4 NONSCIENCE TOTAL 6.2 7.2 8.1 7.5 7.2 7.8 7.0 7.2 6.4 7.3 7.8 7.4 GRAND TOTAL 13.0 14.3 16.4 15.1 10.4 10.9 10.2 10.5 12.7 13.9 15.3 14.4 SOURCE: NRC, Commission on Human Resources. behind that of the parents of the PhD's appears to be roughly on the order of one generation. So we are left with a question, rather than an answer: What is the influence of parents' education? CITIZENSHIP The proportion of PhD's who are of non-U.S. citizenship has been increasing. The data on citizenship of doctorate recipients is limited to the last 15 years or so, but longer-term data on foreign origins of PhD's is available from analysis of baccalaureate origins. These data show a long-term upward trend in doctorate recip- ients who earned their baccalaureate degrees abroad, varying between 7 percent and 9 percent until the 1960's, when the trend was sharply upward, moving up to about 15 percent in the most recent period. The proportion of foreign origin PhD's varies by field, the highest proportions being in the natural sciences and engineering. The behavioral sciences (except economics), the humanities, and education are much more inti- mately bound up with the culture than are the natural sciences; hence U.S. doctoral education in these fields is much less attractive to those of foreign origins than to those who have been immersed in the American culture from the begin- ning of their education. In the period since 1960, the proportion of U.S. PhD's who are foreign citizens has continued to increase, as shown by Table 15 and Figure 35. In Figure 35, the fields have been separated into two groups to simplify the graphic presenta- tion. On the left-hand portion of the page, the EMP fields are depicted; all the other fields are on the right. It is striking that the two fields attracting the largest proportions of non-U.S. PhD's are engineering and agricultural sciences— two applied fields of great economic impact. The third field in terms of proportion of non-U.S. citizens is the group included in medical sciences—also important in terms of the health of the populations to which the results of these sciences are applied. Within the physical science group, the differ- ences in proportion of non-U.S. citizenship are not large; the lines cross and recross and vary from 12-16 percent in the 1960-1964 period to 18-22 percent in 1970-1974, a distinct increase that applies to all fields, although the growth rates are not all the same. In the remaining fields, the changes have not been large, and in some fields—for example, the biosciences—there has been a decline of a few points over the 15- year period. In the professions (a field in which many are employed in applications rather than basic research) and in the humanities there has been a small increase. In the social sci- ences, psychology, and education there has been no significant time trend. In the latter two fields the proportion of foreign citizens is only about 5-6 percent; in the humanities it is slightly higher, moving up from 6 percent to 9 percent over the time period shown. There are sex differences in the proportion, by field, in citizenship. These are shown in Table 15, which also shows the time trends, by field and field group, and 15-year totals. The really striking percentages among the women PhD's might be dismissed as due to the unreliability of small numbers, were it not for the consistency of the time trends and the fact that the total

48 35 30 £25 N r- 5 EMP Fields 20 (9 10 35 30 25 20 All Other Fields Agricultural Sciences Chemistry In percentage terms, foreign citizenship has increased most rapidly for engineering and agricultural sciences; the physical sciences and math are intermediate; the nonscience fields and social sciences have increased least 15 10 I Medical Sciences Social Sciences Biosciences — Professions Humanities Education Psychology 1960-1964 1965-1969 1970-1974 COHORT OF DOCTORATE SOURCE: NRC, Commission on Human Resources 1960-1964 1965-1969 1970-1974 COHORT OF DOCTORATE FIGURE 35 Percentages of non U.S. citizen PhO's by field. across all time periods results in substantial numbers, even in the fields of engineering and agricultural sciences. In these two fields, the very high proportion of non-U.S. citizens may best be thought of in terms of the very small proportion of U.S. women entering these fields, rather than in terms of high proportions among foreign citizens. The same is true, although to a lesser extent, in the other fields of physical science and medical sciences. Another sex dif- ference is the fact that, except for physics and chemistry, the proportion of foreign citizens among the women has increased slightly, or not at all, and in some cases has decreased. This is more likely due to the upswing in the propor- tion of women among U.S. PhD's than to any great change in the trends of foreign citizens enter- ing the United States, since the upward trend in proportion of non-U.S. citizens has continued in the case of men.

48 TABLE 16 RACIAL/ETHNIC GROUPS IN THE DRF, 1973-1975, BY FIELD OF PhD, BOTH SEXES AND ALL CITIZEN CATEGORIES COMBINED - • /V ^ /. ?/ ' / //j f j a J f 4? 4 ' f 1 ^ -•••..-SMI'. N 212 M 71. V 3. , ,M .1 ?7 » '?•{ .1 467 15.7 2974 100.0 PHYSICS N 240 H 68. fi ;? ^ ^ .J W 3517 100.0 CHEMISTRY N 111 1:1 ,:( 4!! ,{!, •ill 3! 2 11. 0 5^4 5l5 EMITH SCIS N J03r V l" : :! 2:! ,3 2t! Mf f 1 ,oS.'S 6.4 itr 1^8 ENGINEERING N 460 H 59. 1 v 7. ' I? .12' ?! 3.1 5.0 7.0 ,;i }626 1.0 11.8 7731 27. 1 28^4 100.0 9.4 EH* TOTAL N 1336 H 66. is :i is 25 i|:| 51ft ffilS ¥ '/!. 8.6 15.3 19.0 toil 94*1 26.9 4GRIC SCIS N 169 H 64. v 2. 7 65 7 46 3 tit J l**i 2607 H i-? }•? .1 13.0 160.0 1EDICAL SCIS N 97 H 67. 30 4 13 3 130 1 20?! 1445 v 1. 1.3 l.l 1.9 ill zlt 4! 1 2.1 100.0 1.8 BIOSCIEHCES N 608 H 72. V 10. r 149 35 78 1.8 .4 .9 6.5 9.7 11.4 ,li 3 4.1 !?fS 8390 'tfcj >l'.i 10.3 LIFE SCI TOT N 874 H 70. V 1*. 1 244 46 137 2.0 .4 1.1 i 10.7 12.8 20.0 J( 2U8 16*2 1 T.4 15.7 l?5!f PSYCHOLOGY N 519 H 80. v 8. 119 29 39 ,if ill 2 2.T 964 '°9:S 15.0 7.0 SOCIAL SCIS N 648 H 73. v 10. 228 34 61 2.6 .4 .7 10.0 9.5 (.9 ,2:| .!! *:t li:T! 1017 BEHAV SC TOT N 1161 H 76. v 19. 347 63 100 27 Ill 10:! m tof;? 15^2 17°S 14*6 2,:i HUHANITUS 1005 v 16^ 24 13 5 6.1 |(:l 12748 9*7 17*8 22*4 »:l l??:f PROFESSIONS N 269 H 74. [ 79 8 1* 2 •1 125 2 .1 |8T8 3598 V 4. 3*5 2*2 2*0 I't 2'.5 Z.I 4^9 100. 0 4.4 EDUCATION N 1353 i 1192 123 151 1 6.6 .7 .8 S 52.3 34.3 22.0 318 T 9.9 2730 18085 v 22! 28 22:1 6^5 fi:| '8:8 HON-SCI TOT N 2628 V 43^ f 1491 195 319 94 693 2.0 14.1 14 11.9 !J" 34431 1 6?:* 5*:! 46*1 43: i 15.6 39.0 100.0 41.8 GRAND TOTAL N 6007 M 73. * 2279 359 686 3 2.8 .4 .8 124 4908 6.0 74 .1 13798 16.8 82301 loolo 100.0 V 100. •i 100. 0 100.0 100.0 100.0 100.0 100.0 100.0 -N = number of . r.T. • HRC, Ci peraonsi H - horizontal percent; •nilsion on Human Resources. V = vertical percent. RACIAL/ETHNIC GROUPS9 Data regarding minority groups, particularly racial groups, are relatively scarce because for many years the collection of these data was for- bidden to public institutions or projects funded by the federal government. However, in recent years this situation has been reversed, and data are now routinely collected in the Doctorate Sur- vey regarding racial/ethnic identification. Three books have been published by the NAS1"'*' ^The categories of racial/ethnic identification used here are those adopted by the federal government and control all data collection funded by federal sources. 1 JCommission on Human Resources, Minority Groups among United States 0octorate Level Scientists, Engineers, and Scholars, 1973 (Washington, D.C.: NAS, December 1974). 1'Dorothy M. Gilford and Joan Snyder, Women and Minority PhD's in the 1970's: A Data Book (Washington, D.C.: NAS/NRC, November 1977). and the National Board on Graduate Education,12 which draw heavily on the DRF and the Comprehen- sive Roster of Doctoral Scientists and Engineers. The present report will therefore be relatively brief and limited to data collected in the DRF for FY 1973 and 1974 and the first half of FY 1975—the only years for which any racial/ethnic data were available in the DRF in time for this analysis. The data for both FY 1973 and 1975 are incomplete; the combined data for the entire period will be presented without chronological breakdown. Because these data include non-U.S. citizens, they are not suitable as a base for affirmative action programs. Readers are re- ferred to the other publications listed in the footnotes for more detailed tables. Table 16 provides the essential information by racial/ethnic groups and field for the 1973- 1975 period, for both sexes and all citizenship categories combined. Table 17 provides data in the same format by sex. We will examine the field differences first for the combined sex group and then for each sex. One of the factors to be remembered in all of these data is that there is a correlation between racial/ethnic identification and foreign citizenship: the foreign citizen PhD's include a lower percentage of whites and higher percentages of the minority groups, with the exception of American Indians. This affects particularly those applied science fields of engineering, agricultural sciences, and medical sciences, which are relatively more important to the developing countries; these countries also have a smaller percentage of whites than does the United States. In Tables 16 and 17 the racial/ethnic groups of the Doctorate Survey are arranged in columns, and the fields of doctorate in rows. In Table 17, the data for men are presented in the left half of the table, and the data for women in the right half. In both tables, both horizontal and vertical percentages are given. Horizontal percentages show the percentage of each racial/ ethnic group as a proportion of the total for that field; the vertical percentages show the field mix for each racial/ethnic group. Both sets of percentages are important for an under- standing of the data. Scanning first down the column for whites, it is apparent that this group largely determines the field mix percent- ages for the total of all groups, since whites constitute three-fourths of the total. The only field group that is significantly lower for whites than for the total is engineering; the reason for this lower percentage is the heavy predominance of engineering as a field of choice for Orientals. The second column is for blacks. Here we note a lower-than-average percentage in all the nat- ural science fields, particularly the EMP fields. The reasons for the lower percentages in so many fields is apparent in the final field— education. Here we find over half of the blacks as compared with 22 percent for all racial/ ethnic groups combined; this concentration I2National Board on Graduate Education, Minority Croup Par- ticipation in Graduate Education (Washington, D.C.: June 1976).

60 TABLE 17 RACIAL/ETHNIC GROUPS IN THE DRF, 1973-1975, BY FIELD OF DOCTORATE AND SEX, U.S. AND FOREIGN CITIZENS COMBINED Men 4 Women s .// ^ // / /, ' c- * ~* * O *1 S -e f ** W mf O V / £* * -v 2 v,« o £ 9 i 3 / */ f *J O 4 1fFfi •-f lU C ". O -Y * * *? if ^ c- O *l ^ ** f O 4) MATHEMATICS N ,916 )3? 9 21 t 263 4 436 2686 212 9 38 13.2 .7 10.8 288 100.0 H 73.6 V 4.0 2317 2.0 20 4.0 3364 1.8 85 .6 5.9 37 33.3 1.3 28 1.8 153 PHYSICS N 9 367 7 619 1 I 1 H 3.6 .2 18.4 .7 24.2 18.3 1 00. t V 4.8 1.2 3.2 3.2 8.6 10.3 5.4 5.1 .7 .2 1.3 .9 5.8 1.2 1.0 CHEMISTRY N 2890 M 8 28 4 451 4 648 4092 293 2 I 90 63 440 H 70 6 1.4 .2 .f 11.0 15.8 i.I JO.O 14.0 100.0 V 6.0 3.5 2.8 4.8 4.3 10.6 9.9 5.6 6.2 2.4 .3 4.1 2.7 2.8 EARTH SCIS N 987 7 8 3 89 2 245 1351 52 t 2 10 65 H 73.1 .5 .6 .2 6.6 .1 18.1 100.0 80.0 1.5 3.1 15.4 100.0 V 2.1 2.8 1.7 3.2 2.1 2.4 2.1 2.0 .4 1.3 .1 .4 .4 ENGINEERING N 4545 70 18 48 11 1314 21 1607 7634 64 14 19 97 H V 59.5 9.5 .9 4.1 .2 6.4 6.1 111* 17.2 30.8 3019 21.1 14.0 100.0 11.5 66.0 .5 14.4 2.2 19.6 .8 103.0 .6 EMP TOTAL N 12655 189 52 129 25 2484 38 3555 19127 706 8 3 1 181 2 151 1052 H 66.2 .3 .7 .1 13.0 .2 18.6 100.0 67.1 .6 .3 .1 17.2 .2 14.4 1OO.O V 26.3 11.2 18.4 22.2 58.2 55.9 31.0 28.8 5.9 1.4 3.9 .9 28.3 33.3 6.5 6.7 AGRIC SCIS N H 1627 65.2 64 7 .3 46 1.1 3 308 6 435 17.4 2496 100.0 63 56.8 .i I5'I ioo!i 2.6 27.0 V 3 4 3.8 2.5 7.9 3.8 4.7 . 7 . T MEDICAL SCIS N H 763 65.8 27 4 .3 12 1.5 104 9.6 .1 245 1160 208 73.0 .1 1 26 .4 9.1 46 16.1 285 2.3 .2 2.4 4.4 100. 0 y 1 i A 1.6 2.1 1.7 .9 3.3 4.1 2.0 1.8 B10SCIENCES N 4777 107 26 6f 10 458 3 1164 6614 1310 42 9 9 2 142 262 1776 H 72.2 1.6 .4 1.0 .2 6.9 17.6 100.0 73.8 — 4 .5 O 22l2 14.8 100.1 V 9.9 6.3 9.2 11.9 10.6 10.7 4.4 10.1 9.9 10.9 7.1 11.7 a. 5 11.3 11.2 LIFE SCI TOT N 7167 198 37 • 27 IS 870 12 1844 10270 1581 46 9 10 3 198 325 §172 H V 69.8 14.9 1.9 11.7 .4 13.1 2ll9 U.Ic) 8.5 20.4 17l6 18.0 16.1 100.0 15.4 72.8 13.1 .4 .5 lllfl 3<K9 15.0 14.0 0.0 13.7 PSYCHOLOGY N 3647 82 23 30 10 49 1 668 4510 1548 37 9 2 32 1 296 1931 H 80.9 1.8 .5 .7 1.1 14.8 100.0 BO. 2 1.9 .3 .} .1 1.7 .1 15.3 100. D V 7.6 4.9 8.2 5.2 10.6 I.I 1.5 5.8 6.8 12.9 6.3 7.8 8.5 6.7 5.0 16.7 12.8 12.2 SOCIAL SCIS N 5280 192 29 52 350 f 1376 7292 1207 36 S 9 7 51 L iS?i 1516 H 2.6 9.0 all ?:i 18 9 6.5 8.5 V 11.0 11.4 10.3 8.2 12.0 11. 0 10.0 6.1 23.3 8.0 16.7 8.6 9.6 BEHAV SC TOT N 8927 274 52 82 18 399 6 2044 17.3 11802 2755 73 1J l? 9 83 2 496 3447 H V 18.6 16.2 18.4 14.1 19.1 9.3 8.8 17.8 17.7 22.9 12.3 14.3 17.0 30.0 13.0 33.3 21.4 21.8 HUMANITIES N 6988 78.5 14.5 153 46 .5 107 1.2 186 2>1 4.4 4 5.9 1406 15.8 12.2 8906 100.0 13.4 3065 79.8 25.5 67 ii 23.4 47 1 572 14.9 16.7 24.7 3842 103.0 24.1 H 1.7 9.1 17lo 1.7 11.3 1.2 26^7 Ifllo V 16.3 18.4 44.3 PROFESSIONS N H 2331 55 1.8 7 13 .4 .1 109 3.5 .t 589 19.0 3108 362 73.9 24 .1 16 86 490 1 00.0 75.0 2*1 100.0 4.9 1.1 .2 3.3 17.6 V 4.9 3.3 2.2 2.1 2.6 2.9 5.1 4.7 3.0 4.1 .9 2.5 3.7 3.1 EDUCATION N H V 9962 818 3,3 l?9 220 6 8.8 2044 15.4 17.8 PooIS 3574 74.3 29.7 374 7.8 63.2 35 29 10 98 .2 2.0 33.3 15.3 1 686 14.3 16.7 29.6 4807 103.0 30.4 75.0 20.7 19ll 20.0 45^5 .6 27.4 NON-SCI TOT N 19261 1026 141 242 36 515 12 4039 25292 7001 465 54 77 IB 178 2 1344 9139 H 76.2 40.1 .6 50.0 1.0 41.7 3813 2.0 12.1 3l:? 100.0 38.0 76.6 58.1 5.1 78.5 .6 70.1 .8 72.6 .2 1.9 60.0 27.8 14.7 33.3 58.0 100.0 57.8 V 17.6 GRAND TOTAL N 48030 1687 282 580 94 4268 68 11482 66491 12043 592 77 106 30 640 6 2316 15810 5 72.2 100.0 2.5 ,oo!o .9 loolo 6.4 .1 100.0 17.3 100.0 100.0 100.0 76.2 100.0 3.7 100.0 .5 .7 .2 4.0 100.0 100.0 14.6 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 10P.O *N = number of individuals; H = horizontal percentage; V = vertical percentage. SOURCE: NRC, Commission on Human Resources. forces lower percentages elsewhere. The American Indian column shows percentages that seldom devi- ate far from the average of all groups, consider- ing the unreliability of percentages based on small numbers. The American Indians are low in the EMP fields, except the earth sciences, and high on education, although not to the extent that characterizes the black population. The fourth column combines Spanish Americans, Mexican Americans, and Chicanos, and the fiftii column the other Spanish-speaking group, Puerto Ricans. The data for these two columns are simi- lar, except that the former group has a higher percentage in the agricultural sciences. Again, the unreliability due to small numbers must be noted.

61 Orientals include those of both east Asian and south Asian origins--a limitation of the data that complicates interpretation. As noted earlier, this group is very high in engineering and high also in the other EMP fields and, to a lesser extent, in the life science fields. The natural sciences combined claim over three- fourths of the Oriental group; the remaining fields are correspondingly depleted in terms of percent as compared with the total of all racial/ ethnic groups, particularly in psychology and education--two fields in which the cultural com- ponent is very high. The column labeled "other" usually does not deviate very far from the total of all groups, but is a bit high in mathematics, physics, engineering, agricultural sciences, and medical sciences and relatively low in the fields most closely tied to the American culture. This seems to be a function of the foreign origins of a substantial portion of this group—many of whom could not readily fit their racial/ethnic identification into the DRF categories. Finally, the unknown group has field percentages that never deviate importantly from the total of all groups—an indication that there is no substan- tial bias hiding in the "unknown" category. SEX DIFFERENCES Table 17 contains the same data as does Table 16 but they are separated into tables for men and for women. Here we note that the pattern of sex differences is, in the main, that which is typi- cal of the general PhD population—there are relatively fewer women in the sciences, particu- larly the EMP fields and the professions, while there are relatively more women in education and psychology. This pattern applies in general across all the racial/ethnic groups; the small numbers make separate consideration of particular groups hazardous, but the data are presented for whatever uses readers may wish to make of them. OF AGE AND THE DOCTORATE There is an old expression among those who have studied the rate of academic progress in elemen- tary schools: "the lockstep of the grades." As one consequence, students graduate from high school at age 18, with only a small spread on either side of this figure. If they then go on to college, as a high proportion do, they typi- cally graduate in 4 years, again with a small spread on either side of a median age of 22 years. But, for a variety of reasons, the spread is greater than at high school graduation; the standard deviation, for those who go on to the doctorate at least, is typically 2 or 3 years. The attainment of the doctorate is another matter entirely; the lockstep is thor- oughly broken, and the distribution of ages is very wide—the standard deviation is 7 years. The "4-year plan" for the doctorate actually holds for only a small percentage of students. The typical age is a function of field of PhD and sex. Women, who are younger at the baccalau- reate, are typically older at the doctorate, for a variety of reasons. The typical age at which one receives the PhD degree is about 30 in the science fields and mid- to-late 30's in the nonscience fields. The sex differences occur mostly in the behavioral sci- ence and nonscience fields. The field differ- ences are vast, ranging from a mean age of 29 in chemistry to around 40 in education. These age differences reflect primarily the typical educa- tional practices in the different fields, but to some extent they may also reflect student selec- tion or self-selection differences. This is indicated by the fact that there are systematic age differences at the baccalaureate degree level, paralleling those at the PhD. Perhaps even more interesting than the mean differences by sex and field are the differences in the distributions about those means. The distributions are highly skewed—particularly at the doctorate level but also at the baccalaureate. At the younger end of the distribution there is not much difference by sex or field. But at the older end of the distribution the differences are great—by both sex and field. Figure 36 presents, in diagrammatic fashion, the distributions of age at baccalaureate and doctorate for the two sexes separately for sev- eral field groups. (Table 18 shows data for more detailed field breakouts.) The fields shown in Figure 36 are those in which strong dif- ferences are evident; where the differences are smaller, the fields are grouped. The EMP fields— engineering, mathematics, and the physical sciences—do not vary greatly in age statistics and have been grouped as shown on the top lines of Figure 36. Here we note that there is a sex difference. The women, shown with the dotted line with an arrow marking the mean age, are younger than are the men on the average. At the baccalaureate level they are younger at all per- centile points in the age distribution, but at the doctorate level the 90th percentile for women is higher than that for men. In a similar manner, the pattern of all field groups and both sexes may be examined. As one does so, the field differences, the sex differences, and the pattern of mean time lapse between baccalaureate and doctorate become apparent. The second pair of lines in Figure 36 shows the data for the life sciences, and again, as in the EMP fields, the women are younger than the men at the baccalaureate level, except at the 90th percentile. At the doctorate level, on the other hand, the age distributions are higher for women than for men. Something is interven- ing to lengthen the time it takes women to com- plete graduate school. In the behavioral sciences, the pattern of the life sciences is repeated but with greater emphasis. In the humanities fields, this pattern is further devel- oped, and it becomes extreme in the professional fields and in education. Next to the bottom, these latter three fields are grouped into a nonscience total. Finally, the total of all fields, sciences and nonsciences combined, is shown with broader lines to set it off from the separate field groups. The marked sex differ- ence evident in the total is due in large part to the higher proportion of women in those

Baccalaureate EMP Fields Doctorate 2Sth 75th 90th Percentile Percentila Percenrils Man II I Life Sciences l I Woman Mean Behavioral Sciences I I l 1 I — Lj ---- 1 Humanities l l l I __ Lj _____ I Professions l l . « U-L, Education 4. 1 I N on sciences, Total GRAND TOTAL OF ALL FIELDS . t 1 1 1 1 1 1 1 20 25 30 35 40 45 a AGE AT GRADUATION SOURCE: NRC, Comm.ss.on on Human Resources FIGURE 36 Age distributions at baccalaureate and doctorate. fields in which the sex differences are most pronounced. More detail is shown in Table 18. The five fields of the EMP group are given separately, as well as in combination. The first pair of col- umns (for men and women separately) gives mean age; the standard deviation is given in the second pair of columns, and the 25th, 50th, 75th, and 90th percentiles in the remaining columns. Age at baccalaureate is shown in the top half of the table, and age at doctorate in the bottom half. One notes immediately that the standard devi- ations of age are greater for women than for men—with only two exceptions at the doctorate level and none at the baccalaureate level. This is to be expected if there are more factors that slow the rate of progress of women; the size of the standard deviation is largely determined by the numbers in the older age ranges. We have seen earlier that women come from better-educated families on the average, and previous studies have shown that they have higher average academic aptitude (those who attain the doctorate—not women in general). It is no surprise, therefore, that they complete undergraduate work at a younger age. But the greater spread about the mean age, and the skewness of the distributions, seem to indicate that for a significant portion of women there are forces at work—marriage,

53 TABLE 18 AGE AT BACCALAUREATE AND DOCTORATE, BY SEX AND FIELD OF PhD, 1960-1974 Age at Baccalaureate Mean Std. Dev. 25th Percentile 50th Percentile 75th Percentile 90th Percentile Field of PhD Men Women Men Women Mm Women Men Women Men Women Hen Women Mathematics 22.2 22.0 1.88 2.16 21.4 20.9 22.0 21.7 22.6 22.4 24.1 23.7 Physics 22.3 21.8 1.76 1.87 21.5 20.9 22.0 21.7 22.6 22.3 24.1 23.3 Chemistry 22.4 22.2 1.71 2.01 21.6 21.3 22.1 21.9 22.8 22.5 24.2 23.6 Earth science 22.9 22.6 2.21 2.54 21.7 21.6 22.3 22.1 23.5 22.7 25.7 24.0 Engineering 22.7 22.3 1.95 1.96 21.7 21.3 22.3 22.1 23.3 23.0 24.9 24.3 EMP TOTAL 22.5 22.1 1.88 2.06 21.6 21.2 22.2 21.9 23.0 22.4 24.5 23.6 Agricultural science 23.4 22.4 2.63 2.75 21.9 21.3 22.6 22.0 24.4 22.8 26.6 24.3 Medical science 23.0 23.9 2.34 4.58 21.7 21.6 22.5 22.3 23.7 23.8 25.8 30.0 Biosciences 22.9 22.4 2.31 2.75 21.7 21.3 22.3 21.9 23.4 22.4 25.7 24.1 LIFE SCIENCE TOTAL 23.1 22.6 2.41 3.02 21.8 21.3 22.4 21.9 23.6 22.5 26.0 25.5 Psychology 23.1 23.0 2.70 4.24 21.7 21.2 22.3 21.9 23.5 22.6 26.1 25.6 Social science 23.3 23.2 3.04 4.43 21.7 21.2 22.3 21.9 23.9 22.7 26.5 27.2 BEHAVIORAL SCIENCE TOTAL 23.2 23.1 2.91 4.32 21.7 21.2 22.3 21.9 23.8 22.6 26.3 26.9 SCIENCE TOTAL 22.8 22.7 2.33 3.59 22.2 21.7 22.3 22.4 23.2 23.0 25.9 25.7 Humanities 23.1 23.3 3.01 4.69 21.7 21.2 22.3 21.9 23.5 22.8 26.2 28.0 Professions 23.3 23.1 3.22 4.24 21.7 21.1 22.4 21.9 23.9 22.8 26.6 27.6 Education 24.0 24.3 3.40 5.49 22.0 21.3 22.9 22.1 25.1 24.5 27.6 32.2 NONSCIENCE TOTAL 23.6 23.8 3.27 5.12 21.8 21.3 22.5 22.0 24.4 23.4 27.0 30.6 GRAND TOTAL 23.1 23.3 2.72 4.56 21.7 21.2 22.3 22.0 23.6 23.0 26.0 28.2 Age at Doctorate Mean Std. Dev. 25th Percentile 50th Percentile 75th Percentile 90th Percentile Men Women Men Women Men Women Mm Women Man Women Men Women Mathematics 29.7 30.6 4.37 5.64 26.6 26.7 28.6 28.9 31.5 32.9 35.2 38.5 Physics 29.8 29.7 3.87 3.85 27.2 26.9 28.9 28.8 31.3 31.2 34.6 34.6 Chemistry 29.1 29.7 3.86 4.78 26.5 26.6 28.1 28.3 30.6 31.1 33.8 36.0 Earth science 31.8 32.3 5.09 6.02 28.2 28.0 30.6 30.4 34.1 36.0 38.6 41.8 Engineering 31.1 30.8 4.89 4.73 27.7 27.7 29.9 29.4 33.2 32.8 37.5 37.0 EMP TOTAL 30.2 30.1 4.52 5.00 27.1 26.7 29.1 28.7 32.1 31.7 36.1 37.0 Agricultural science 32.5 32.1 5.34 5.85 28.6 28.2 31.2 30.7 35.1 34.1 39.8 39.1 Medical science 32.5 35.4 5.44 8.12 28.6 28.7 31.3 32.8 35.2 41.1 39.8 47.8 Biosciences 31.0 31.3 4.71 6.07 27.7 27.1 29.8 29.3 33.0 33.5 37.1 40.1 LIFE SCIENCE TOTAL 31.5 31.8 5.00 6.42 27.9 27.3 30.3 29.5 33.7 34.3 38.2 41.5 Psychology 31.1 33.1 5.33 7.53 27.3 27.5 29.5 30.5 33.2 37.1 38.2 44.7 Social science 33.0 34.6 6.14 7.74 28.6 28.7 31.5 32.2 35.8 38.9 41.8 46.4 BEHAVIORAL SCIENCE TOTAL 32.3 33.7 5.92 7.65 28.0 28.0 30.7 31.2 34.9 37.9 40.5 45.6 SCIENCE TOTAL 31.0 32.4 5.09 6.96 26.7 27.9 30.2 30.5 33.6 35.8 38.2 39.0 Hunanities 33.6 35.5 6.26 8.11 29.1 29.3 32.1 33.1 36.6 40.0 42.4 47.6 Professions 35.2 39.3 6.82 8.58 30.1 32.1 33.5 38.8 38.9 45.4 44.6 51.2 Education 37.6 40.5 6.93 8.50 32.2 33.6 36.6 39.9 42.1 46.6 47.4 52.3 NONSCIENCE TOTAL 35.8 38.3 6.93 8.69 30.5 31.0 34.5 36.9 39.8 44.3 45.6 50.8 GRAND TOTAL 32.7 35.8 6.22 8.51 28.1 28.9 31.0 33.4 35.6 41.4 41.7 48.5 SOURCE: NRC, Commission on Human Resources. children, economics, and perhaps others—that prevent the rate of academic progress typical of their male counterparts. The effect of cases at the extremes of the distributions, particularly at the range beyond the 90th percentile, account for the high stan- dard deviations in the several field and sex groups where they have been noted. To get a better picture of the numbers who graduate in the upper age ranges, at both degree levels, we have the data of Table 19. In the EMP fields, few persons of either sex are over 30 at the time the baccalaureate degree is earned, as shown in the top left pair of columns in Table 19: 0.89 percent for men and 1.52 percent for women. As we go down the column, however, to

54 TABLE 19 PERCENTAGE OF DOCTORATE POPULATION IN SUCCESSIVE "OVER-AGE" BRACKETS AT BACCALAUREATE AND DOCTORATE, BY SEX AND GENERAL FIELD OF PhD, 1960-1974 Age at Baccalaureate Age at Doctorate 30 and Over 40 and Over 50 and Over 40 and Over 50 and Over 60 and Over Field Group Men Women Men Women Men Women Men Women Men Women Men Women EMP Fields Life sciences Behavioral sciences Science total 0.89 2.10 3.31 1.77 1.52 3.81 7.00 4.89 0.03 0.10 0.35 0.13 0.05 0.47 1.68 0.96 0.01 0.01 0.03 0.01 0.00 0.01 0.09 0.05 4.52 7.37 11.35 6.88 6.19 0.43 0.67 1.72 0.80 0.59 2.23 4.68 3.08 0.02 0.03 0.12 0.05 0.00 0.10 0.30 0.18 12.47 20.97 15.31 Humanities Professions Education Nonscience total 3.29 4.15 5.38 4.46 8.35 7.69 13.87 11.18 0.48 0.57 0.69 0.60 1.93 0.07 0.06 0.03 0.05 0.21 15.15 22.51 34.77 25.99 26.03 44.75 50.62 40.52 2.39 4.05 5.89 4.37 6.98 12.84 15.92 11.98 0.23 0.26 0.26 0.25 0.90 0.86 1.11 1.01 1.16 2.82 2.34 0.12 0.14 0.17 GRAND TOTAL 2.71 8.49 0.29 1.75 0.03 0.12 13.50 29.72 2.04 8.17 0.12 0.65 SOURCE: NRC, Commission on Human Resources. the life sciences, behavioral sciences, and especially to the nonscience fields, the pro- portion over 30 increases quite markedly, par- ticularly in the case of women. Almost one in seven of the women who earn the doctorate in education is over 30 at the time she earns the baccalaureate degree. The proportion over 40 at the time of the baccalaureate is smaller but still surprisingly high and follows the same general pattern of sex and field differences. Finally, there are some—very few, to be sure, but still some cases in all fields—who are over 50 at the time the baccalaureate degree is earned. The field and sex differences persist, indicating that this is a real phenomenon, not a figment of random errors in the tabulation processes. At the doctorate level, the ages represented in the three sets of columns have been moved up a decade, to indicate percentages earning PhD's at the age of 40 or over, 50 or over, and 60 or over. In the case of the nonscience fields, the percentages of both men and women who are beyond the half-century mark at the time the doctorate is awarded is surprisingly high, ranging from over 2 percent for men in the humanities to al- most 16 percent of women in education. Taking all fields together, as shown at the bottom line in Table 19, we see that at least 1 man in 50, and 1 woman in 12 is at least 50 years old when the doctorate is awarded. The numbers who are 40 or over are larger, of course, and the propor- tions are indeed surprisingly large; even in the EMP field group, 4.5 percent of the men are over 40 at the time of the doctorate; in the nonscience fields the proportion is 1 in 4 for the men and 4 in 10 for the women. TIME TRENDS IN AGE AT DOCTORATE Have the field and sex differences in age at PhD been constant for the entire 15-year period under examination? Table 20 provides some of the an- swers. Sex differences and field differences have been decreasing over the last 15 years. Convergence has begun, but there is still a long way to go before the differences are insignificant. BACCALAUREATE-TO-DOCTORATE TIME LAPSE As we have seen, the primary determiner of age at doctorate is the time lapse between the bacca- laureate and doctorate degrees, although age at BA is also a contributing factor. This time lapse, and that portion of it represented by time registered in graduate school, has been the sub- ject of a number of studies, including the pre- vious volume in this series, Doctorate Recipients from United States Universities, published by the NAS in 1967. Our primary concern here will be with field and time differences in the total time lapse, disregarding the differentiation into reg- istered time and time not in study status. TABLE 20 MEAN AGE AT PhD, BY FIELD, SEX, AND 5-YEAR COHORTS, 1960-1974 1960-1964 1965-1969 1970-1974 Field of Doctorate MM) Women Men Women Men Women Mathematics 30 .2 31. 9 29, .2 30 .4 29.8 30 .4 Physics 29 .* 31. 7 29.6 29 .2 29.9 29 .5 Chemistry 29 .2 29. 9 2« .9 29 .7 29.2 29 .6 Earth sciences 31 .6 — 31 ,7 32 .6 32.0 31, .8 Engineering 31.0 31. 0 31 .0 30.9 31.3 30.7 EMP TOTAL 30 .2 30. 7 30 .0 X .0 30.4 30 .0 Agriculture 32 .4 32. 7 32 ,6 31 .4 32.4 32.0 Medical sciences 33 .1 36. 0 32 .5 35 .6 32.3 35. .2 Biosciences 31 .5 32. 8 31 .0 31 .3 30.6 31 .0 LIFE SCIENCES TOTAL 31.9 33.0 31 .5 31 .6 31.3 31 .5 Psychology 31 .9 34. B 31 ,1 33 .6 30.7 32 ,5 Social sciences 33 .9 36. 7 33 .1 35 .7 32.7 33 .8 BEHAVIORAL SCIENCES 33 .1 ?5. 4 32 ,3 34 .4 32.0 33 .0 SCIENCE TOTAL 31 .3 33. 7 30 .9 32 .5 31.0 32 ,0 Humanities 34 .1 36. a 33 .6 35 .8 33.4 35 .0 Professions 35 .4 40. 0 39 .S 40 .2 34.9 38 .6 Education 38 .4 42. 5 37.8 41 .3 37.2 39 .6 NONSCIENCE TOTAL 36 .3 40. 1 35 .9 38 .* 35.6 3? .6 GRAND TOTAL, ALL FIELDS 32 .9 37. 3 32 .S 36 .1 32.7 35 .3 SOURCE: NRC, Commission on Human Resources.

55 TABLE 21 MEAN BACCALAUREATE-TO-DOCTORATE TIME LAPSE, BY FIELD, TIME PERIOD, AND SEX Field of Doctorate 1920- 1945- 1950- 1960- 1920- 1944 1949 1959 1974 1974 Females 1920- 1945- 1950- 1960- 1920- 1944 1949 1959 1974 1974 Both Sexes Combined 1920- 1945- 1950- 1960- 1920- 1944 1949 1959 1974 1974 Mathematics 7.46 8.89 8.13 7.41 7.56 9.45 9.35 10.79 8.61 8.98 7.74 8.93 8.26 7.49 7.66 Physics and Astronomy 7.04 7.98 7.38 7.48 7.43 8.85 7.81 8.52 8.01 8.22 7.12 7.98 7.40 7.49 7.45 Chemistry 5.89 7.04 6.52 6.73 6.54 8.43 8.02 8.23 7.51 7.80 6.04 7.09 6.60 6.69 6.62 Earth sciences 7.85 9.47 8.13 8.89 8.64 8.11 — 10.13 9.78 9.57 7.86 9.56 8.17 8.91 8.67 Engineering 7.31 8.27 8.05 8.37 8.29 — ~ — 8.57 9.06 7.31 8.29 8.07 8.38 8.30 EMP TOTAL 6.53 7.73 7.32 7.72 7.52 8.68 8.56 8.92 8.01 8.27 6.65 7.77 7.36 7.73 7.55 Life sciences 7.69 9.36 8.09 8.36 8.25 9.01 10.12 10.02 9.27 9.37 7.88 9.46 8.27 8.48 8.39 NATURAL SCIENCE TOTAL 6.97 8.26 7.59 7.92 7.76 8.89 9.54 9.64 8.84 8.98 7.14 8.36 7.70 7.99 7.85 Psychology 8.07 9.11 8.04 e.oo 8.04 9.38 10.08 11.52 10.31 10.38 8.42 9.32 8.55 8.55 8.56 Social sciences 9.32 11.64 10.50 9.83 9.96 11.48 12.25 13.10 11.73 11.89 9.56 11.70 10.70 10.06 10.18 BEHAVIORAL SCIENCE TOTAL 8.98 10.87 9.44 9.12 9.22 10.36 11.12 12.14 10.88 11.00 9.20 10.91 9.73 9.42 9.50 Humanities 9.71 11.99 11.37 10.81 10.81 12.09 14.26 15.15 12.89 13.08 10.23 12.44 11.91 11.25 11.26 Education 13.56 15.53 14.81 13.71 13.95 14.61 17.01 17.72 16.74 16.73 13.78 15.86 15.34 14.36 14.53 TOTAL, ALL FIELDS 8.58 10.36 9.65 9.62 9.54 11.25 13.19 13.98 12.68 12.70 8.97 10.75 10.08 10.05 9.96 Source: NRC, Commission on Human Resources MEAN TIME LAPSE, BY FIELD AND SEX Table 21 provides an overview of the mean BA-to- PhD time lapse, by field and field group, in terms of four general time intervals. The ear- liest interval represents PhD graduations in the quarter-century from 1920 to 1944. Although this includes most of the World War II period, most of the people earning doctorates during the war years had completed the major portion of their graduate work earlier. Only the last four years of this period could have been affected by the war. The second time period is 1945-1950, during which the returning veterans and the "GI Bill" played an important part in the campus scene. The third period is 1950-1959, during which time the effect of the war period and Veterans Administration programs was diminish- ing. The fourth period is the most recent 15 years, which has been examined in some detail in previous sections. As in the previous tables relating to age, sex differences are evident, and time trends in these differences are of some interest. In the EMP fields, for instance, although women are relatively few, it is clear from Table 21 that during the 1945-1949 period they took less time to attain the doctorate than in either the pre- ceding or the following period. For the men graduating during this period, exactly the oppo- site is true, because this period includes the graduations of the greatest number of those whose educational careers had been interrupted by military service. In the 1950's, the mean time lapse for men went down, whereas for the women it went up. In the most recent period, the time trends are again reversed, going up for the men and down for the women, with the net effect that the disparity between the data for men and women is at a minimum in the recent past—partic- ularly, as we have seen in the age data, in the last third of this 15-year period. TIME TRENDS IN TIME LAPSE The data of Table 21 are means and neglect the important matter of variations. These varia- tions can be expressed in two ways. The first is percentile distributions. One of the best ways to visualize variations over a period of time is to examine changes in the percentile points. Figure 37 does this for chemistry, which represents the field with the minimum time lapse. Figure 39 does this for the life sciences, an intermediate field, and Figure 41 does this for education, the field with the greatest BA- to-PhD time lapse. An alternative view of the same data is provided by a set of isochrons— lines of equal time lapse taken by varying proportions of the population. Figures 38, 40, and 42 provide such data for the same three fields. Percentiles and Isochrons When one compares Figures 37 and 38, represent- ing changes in baccalaureate-to-doctorate time lapse in chemistry from 1920 through 1974, by 5-year intervals, one notes that in Figure 37 the lines of percentile trends are crowded close to the bottom of the figure. In Figure 38 by contrast, the isochrons, representing changes over time in the percentage of persons requiring a constant amount of time for the BA-to-PhD interval, are crowded toward the top of the figure. Chemistry has for 50 years or more been the field with the shortest average time lapse. During the 1920's and 1930's, the median time lapse was about 5 years. This was even improved slightly in the early 1940's, but the delays occasioned by World War II raised the median time to over 6 years, from which it dropped a bit until the most recent 5-year period, when another increase is seen. The other percentile points can be traced in a similar manner. It is noteworthy, however, that the time required by

Chemistrv is a field with a relatively brief BA-to PhD time lapse; «v«n the fastest students are taking longer 16 r- UJ BA-PhD Time Required by Slowest 5% of Chemists Time Required by Fastest 5X of Chemists I 1920 1930 1940 1950 1960 1970 YEAR OF DOCTORATE GRADUATION SOURCE: NRC, Commission on Human Resources FIGURE 37 BA-to-PhD time lapse percentiles: chemistry. the fastest 10 percent, or even 5 percent, has drifted gradually upward over almost the whole of the 1920-1974 period, with a slight perturba- tion at the time of World War II. At the slow end of the time scale—the curves for the slow- est 5 percent and the slowest 10 percent—the variations from one era to another were larger, but there is no consistent upward slope to the curves. The same data are interpreted somewhat dif- ferently by the isochrons of Figure 38. Here we see, in the bottom line, that the proportion of chemists taking only 4 years between the BA and PhD degrees has declined rather steadily (except for the World War II period), from about 20 per- cent in 1920 to about 2 percent in the recent past. The proportion requiring 5 years or less has declined from 40 percent in the early 1920's to about 17 percent recently. The proportion requiring 6 years or less went up from about 57 percent in the early 1920's to 65 percent in the late 1940's, then plummented during the World War II period to about 35 percent, recov- ered to about the 50 percent point, and has sub- sequently declined to between 40 percent and 45 percent. At the top of the graph, represent- ing those who require 15 years or longer, the proportion is small, but has varied only slightly over the years. Isochrons provide a different perspective on time lapse: the percentage who require a specified number of years to graduate ^ Period since BA Less Than: 100 80 Q 111 85 60 V) w 40 o z cc o a: 20 1920 1930 1940 1950 1960 1970 YEAR OF DOCTORATE GRADUATION SOURCE: NRC, Commission on Human Resources FIGURE 38 Isochrons of BA-to-PhD time lapse: chemistry.

57 The lift «ient« are a "typical" field group in RA.ni PhD time lapse; here, too, the time laps« hes increased for the mott rapid of thestudenti _—^_ 15 BA PhD Time Required by Slowest 5X of Life Scientists BA-tfiD Time Lapse Percentiles: 95th 90ih 50th to have a more long-term, rather than immediate, payoff. Decreased support during World War II no doubt had the effect of increasing the stretch-out of the BA-to-PhD interval. As in chemistry, there was an upward drift in the per- centile curves, a given percentage of the gradu- ates taking longer and longer to complete the doctorate. The isochrons show a corresponding decrease in the proportions finishing in the shorter time intervals and an increase in the proportion taking longer times. The postwar "peak" in isochrons moves to the right as the slower bioscientists graduate; most of them are still speeding up. but the fastest slowing down 1001- Period since BA Less Than: I Time Lapse for Fasten 5% of Life Scientist! I 1920 1930 1940 1950 1960 YEAR OF DOCTORATE GRADUATION SOURCE NRC. Commission on Human Resources 1970 FIGURE 39 BA-to-PhD time lapse percentiles: life sciences. The Life Sciences Similar data are provided for the life sciences in Figures 39 and 40. The life sciences as a group have been slower than the EMP fields and faster than the behavioral sciences in time lapse and were powerfully affected by World War II. Perhaps the greater effect of the war was that there was little perceived imnediate appli- cation of the life sciences in the conduct of the war. In physics and chemistry, applications were evident and abundant; in psychology the applications were also touted, as, for example, in the useful and popular book Psychology and the Fighting Man. Perhaps the life sciences other than in medical applications were expected 1920 1930 1940 1950 1960 YEAR OF DOCTORATE GRADUATION SOURCE: NRC, Commission on Human Resources 1970 FIGURE 40 Isochrom of BA-to-PhD time lapie: life science..

The time lapse sptctrum for education is of * different order from the science field), note the change in the vertical icele 26 20 UJ . ' 15 10 Time Required for Slowest 5% of Educators between Baccalaureate and Doctorate Time Lapse Time Required by Fastest 5% of Educators I I I 1920 1930 1940 1950 1960 YEAR OF DOCTORATE GRADUATION SOURCE: NRC. Commission on Human Resources 1970 FIGURE 41 BA to PhD time lapse percentiles: education. Education The final pair of graphs depict the time inter- vals for those with doctorates in education. On Figure 41 it has been necessary to compress the vertical scale, since a large proportion take longer than the 95th percentile of the other fields. The time trends are generally upward, from 1920 to the "GI period," and generally downward since. It is noteworthy that the ef- fect of World War II is less spectacular than it is in the other fields. This is a function of the longer average time span—the effects are less concentrated in those graduating in a given period and are diffused over a wider range of cohorts. A gradual shifting of the "hump" denoting the effects of World War II is noted as we move up the percentile lines, until the 95th percentile, where it is evident in the last 10-15 years. These are the people who are tak- ing well over 20 years to complete the doctorate. Other Fields In the interest of brevity, percentile graphs and isochron graphs are not presented for the remaining fields. The full set are available from the Commission on Human Resources for those wishing more detail. A few comments, however, may be in order with respect to the time lapse variations by field. In the case of psychology, there was a shortening of the time lapse in the immediate postwar period, perhaps due primarily to the government support of training in clinical psychology, which was seen to be important not only for the rehabilitation of World War II vet- erans, but more generally, so that support was provided by both the Veterans Administration and by the National Institutes of Health. The lat- est period shows an average time lapse in psy- chology lower even than in the 1920-1944 period. This is true of only one other field—mathematics. 100 r- n 1930, a 10-year time lapse was typical in education; now it is at the 30th percentite. wfiile 70% take more than a decade to graduate Period since BA LcnThan: 20 yrs ISyrs 12yrs lOyrs 1920 1930 1940 1950 1960 1970 YEAR OF DOCTORATE GRADUATION SOURCE: NRC. Commiiiion on Human Resources FIGURE 42 Isochrons of BA-to-PhD time lapse: education.

59 TABLE 22 PERCENTAGE OF PhD's WITH MASTER'S DEGREES, BY FIELD AND SEX, 1960-1974 TOTAL Men Women Both Sexes Combined Field of PhD Yes No Total Yes No Total Yes No Total Mathematics 9,565 2,564 12,129 785 135 920 10,350 2,699 13,049 78.9 21.1 100.0 85.3 14.7 100.0 79.3 20.7 100.0 Physics 11,393 6,366 17,759 369 141 510 11,762 6,507 18,269 64.2 35.8 100.0 72.4 27.6 100.0 64.4 35.6 100.0 Chemistry 9,469 13,879 23,348 929 994 1,923 10,398 14.G73 25,271 40.6 59.4 100.0 48.3 51.7 100.0 41.1 58.9 100.0 Earth sciences 4,949 1,397 6,346 137 47 184 5,086 1,444 6,530 78.0 22.0 100.0 74.5 25.5 100.0 77.9 22.1 100.0 Engineering 32,923 3,865 36,788 196 29 225 33,119 3,894 37,013 89.5 10.5 100.0 87.1 12.9 100.0 89.5 10.5 100.0 EMP TOTAL 68,299 28,071 96,370 2,416 1,346 3,762 70,715 29,417 100,132 70.9 29.1 100.0 64.2 35.8 100.0 70.6 29.4 100.0 Agricultural sciences 9,728 1,044 10,772 241 37 278 9,969 1,081 11,050 90.3 9.7 100.0 86.7 13.3 100.0 90.2 9.8 100.0 Medical sciences 3,222 1,814 5,036 531 244 775 3,753 2,058 5,811 64.0 36.0 100.0 68.5 31.5 100.0 64.6 35.4 100.0 Biosciences 19,885 10,145 30,030 3,699 2,490 6,189 23,584 12,635 36,219 66.2 33.8 100.0 59.8 40.2 100.0 65.1 34.9 100.0 LIFE SCIENCE TOTAL 32,835 13,003 45,838 4,471 2,771 7,242 37,306 15,774 53,080 71.6 28.4 100.0 61.7 38.3 100.0 70.3 29.7 100.0 Psychology 13,595 4,103 17,698 4,409 1,333 5,742 18,004 5,436 23,440 76.8 23.2 100.0 76.8 23.2 100.0 76.8 23.2 100.0 Social sciences 22,949 4,857 27,806 3,336 629 3,965 26,285 5,486 31,771 82.5 17.5 100.0 84.1 15.9 100.0 82.7 17.3 100.0 BEHAVIORAL SCIENCE TOTAL 36,544 8,960 45,504 7,745 1,962 9,707 44,289 10,922 55,211 80.3 19.7 100.0 79.8 20.2 100.0 80.2 19.8 100.0 SCIENCE TOTAL 137,678 50,034 187,712 14,632 6,079 20,711 152,310 56,113 208,423 73.3 26.7 100.0 70.6 29.4 100.0 73.1 26.9 100.0 Humanities 31,949 5,063 37,012 10,216 1,340 11,556 42,165 6,403 48,568 86.3 13.7 100.0 88.4 11.6 100.0 86.8 13.2 100.0 Professions 10,611 1,820 12,431 1,671 107 1,778 12,282 1,927 14,209 85.4 14.6 100.0 94.0 6.0 100.0 86.4 13.6 100.0 Education 48,509 1,687 50 , 196 13,771 477 14,248 62,280 2,164 64,444 96.6 3.4 100.0 96.7 3.3 100.0 96.6 3.4 100.0 NONSCIENCE TOTAL 91,069 8,570 99,639 25,658 1,924 27,582 116,727 10,494 127,221 91.4 8.6 100.0 93.0 7.0 100.0 91.8 8.2 100.0 KNOWN TOTAL 228,747 58,604 287,351 40,290 8,003 48,293 269,037 66,607 335,644 79.6 20.4 100.0 83.4 16.6 100.0 80.2 19.8 100.0 SOURCE: NRC, Commission on Human Resources. MASTER'S DEGREES The majority of PhD's hold master's degrees al- though the proportion varies substantially by field of PhD and to some extent by sex. The data showing the numbers and percentages of each field, by sex and for the combined total of both sexes, are provided in Table 22 and shown graph- ically in Figure 43. These data relate to the entire 1960-1974 period, without cohort breakouts. The comments in the next two paragraphs should be read with several caveats in mind. The requirements for the master's degree vary markedly from school to school, from field to field, and may not even be uniform within a given school, since some departments may require a thesis while others may not. In the EMP field group, engineering PhD's with 89.5 percent for men and 87.1 percent for women is highest in percentage of master's degrees, followed by mathematics (78.9 percent and 85.3 percent), earth sciences (78.0 percent and 74.5 percent), physics (64.2 percent and 72.4 per- cent), and chemistry (40.6 percent and 48.3 per- cent) in that order. Chemistry is the only field in which fewer than half of the PhD's have re- ceived master's degrees. It is also the field in which the BA-to-PhD time lapse is least.

60 100 80 Only 40% of the chemistry PhD took master's degrees compared with over 95% of the education PhD's s JMen | Women , II 80 - 70 - 1 60 - g I S 50 — 1 S t 40 I r- 111 £ 30 I in a. 20 - 10 - I 0 1 g. | | | | j s § 32 i ! I f 1 1 1 I 1 S '§ 1 1 £ 111 J i s f 6 5S.S tllii 1 && I I S <8 SOURCE: NRC, Commission on Human Resources FIGURE 43 Percentage of PhD's with matter's degrees. Higher percentages of women than men have master's degrees in mathematics, physics, and chemistry; in the earth sciences and engineer- ing, a higher percentage of women have master's degrees. Within the life sciences group, the agricultural sciences lead by a wide margin, 90.3 percent of the men and 86.7 percent of the women having master's degrees. In the medical and biological sciences, about two-thirds of both sexes in both fields have master's (64.0 per- cent of the men and 68.5 percent of the women). In psychology, there is no sex difference; 76.8 percent have the degree. In the social sciences the percentages are higher: 82.5 percent for the men and 84.1 percent for the women. In the human- ities, the percentages are still higher: 86.3 percent for the men and 88.4 percent for the women. In the professions, there is a notable sex difference—the percentages are 85.4 percent for the men and 94.0 percent for the women. In education, however, the peak is reached: over 96.6 percent of each sex holds the master's degree. Combining across all fields, we note that 79.6 percent of the male PhD's and 83.4 per- cent of the female PhD's hold the master's degree. FIELDS OF SPECIALIZATION There are some students who maintain a particular direction with respect to their interests and field of specialization from the time they enter college as freshmen to the time they complete graduate training. Many others switch fields once or more during their careers in higher edu- cation. Typically, a student tends to specialize more as he advances, but, perhaps more often than we have supposed, he also switches from one major field to another. This may represent a growing awareness of one's deeper interests, a better knowledge of what is actually involved in the work of a given field, a testing of abilities, or the discovery that one does not have the tal- ents for outstanding work in the field of first choice but can compete very effectively in a dif- ferent field. Or it may represent a changing perception of the opportunities, scientific, academic, or financial, in the various fields open to the student. In the current study, we have no data on the reasons for the changes that are observed, but we do have considerable data on changes that have actually occurred. Field

61 TABLE 23 RATIOS OF DOCTORATES TO BACCALAUREATES, BY FIELD, SEX. AND COHORT, 1960-1974 PhD's" Men Women Both Sexes Combined Field 1960- 1964 1965- 1969 1970- 1974 Total 1960- 1964 1965- 1969 1970- 1974 Total 1960- 1964 1965- 1969 1970- 1974 Total Mathematics 0.86 O.flO 0. 70 0 .76 0.59 0 .57 0 .50 0.53 0 .84 0.78 0.68 0.74 Physics 1.02 0.93 0. 85 0 .92 0.82 0 .88 0 .78 0.81 1 .02 0.93 0.85 0.91 Chemistry 0.86 0.83 0. 78 0 .81 0.62 0 .58 0 .55 0.57 0 .84 0.80 0.75 0.79 Earth sciences 1.19 1.20 1. 39 1 .27 1.06 1 .16 1 .33 1.25 1 .19 1.20 1.37 1.27 Engineering 0.88 0.88 0. 88 0 .88 0.66 0 .49 0 .83 0.69 0 .88 0.87 0.88 0.88 EHP TOTAL 0.92 0.88 0. 84 0 .87 0.64 0 .62 0 .59 0.61 0 .90 0.87 0.83 0.85 Agricultural sciences 0.74 0.72 0. 88 .79 0.74 1 .05 1 .32 1.15 .74 0.73 0 0 0.89 0.80 Medical sciences 0.90 1.10 1. 33 i .15 0.44 0 .S4 0 .50 0.51 0 .83 0.97 1.02 0.97 Biosciences 1.37 1.37 1. 19 i .28 1.35 1 .32 1 .18 1.24 1 .37 1.35 1.19 1.28 LIFE SCIENCE TOTAL 1.08 1.11 1. 11 i .10 1.15 1 .16 1 .02 1.08 1 .09 1.12 1.10 1.10 Psychology 1.16 1.03 0. 95 i .02 1.39 1 .20 1 .12 1.18 1 .19 1.06 1.00 1.05 Social sciences 1.05 1.05 1. 03 i .04 0.94 0 .88 0 .98 0.95 1 .04 1.03 1.03 1.03 BEHAVIORAL SCIENCE TOTAL 1.10 1.04 1. 00 i .03 1.19 1 .05 1 .06 1.08 1 .11 1.05 1.01 1.04 .72 Humanities 0.69 0.74 0. 72 0 0.67 0 .77 0 .77 0.76 0 .68 0.75 0.74 0.73 Professions 0.96 1.04 1. 03 1 .02 0.81 0 .78 0 .75 0.76 0 .94 1.00 0.98 0.98 Education 1.77 1.79 1. 82 1 .80 1.64 1 .59 1 .61 1.61 1 .74 1.74 1.78 1.76 NONSCIENCE TOTAL 1.02 1.09 1. 13 1 .10 1.00 1 .04 1 .06 1.05 1 .02 1.09 1.11 1.09 KNOWN TOTAL 1.00 1.00 1. 00 1 .00 1.00 1 .00 1 .00 1.00 1 .00 1.00 1.00 1.00 Only those whose baccalaureate and doctorate fields were known are included in this table. SOURCE: NRC, Commission on Human Resources. switching from the field of baccalaureate to field of doctorate will be the subject investi- gated in this section. Doctorate Fields as Destinations From the perspective of the baccalaureate degree, the fields of doctorate specialization can be viewed as destinations. Most mathematics BA majors may be expected to go on in mathematics if they seek the doctorate. But just how big a majority? And if not mathematics, what other fields do they enter? Each field of baccalau- reate may thus be examined as a point of depar- ture to see what destinations are actually reached by those who have taken baccalaureates in the various fields and gone on to the doctorate. As background for consideration of the spe- cific field-to-field switches, it is useful to consider the relative number in each field who do switch. This number may be expressed as a ratio of doctorates to baccalaureates within the PhD recipient groups in each general field. Table 23 provides these ratios by field, sex, and 5-year cohort for the period 1960-1974. In calculating these ratios, only the cases where both field of baccalaureate and field of doctor- ate were known were used. Figure 44 shows the changes over time for the combined-sex total. In Figure 44, fields have been set forth in three groups to make the graph more legible: the EMP fields, the biosciences/behavioral fields, and the nonscience fields. The horizontal line at 100 represents the balancing point, where the losses to a given field just balance the gains. DONOR AND RECEPTOR FIELDS The switches from field to field are not neces- sarily symmetrical, as can be readily seen in Figure 44 and Table 23. Some fields—those with fewer PhD's than BA's—may be considered "donor" fields, since some of their baccalaureates are "given" to other fields. Others may be consid- ered "receptor" fields, since they receive more people whose baccalaureates were in other fields than they contribute to those other fields. It is this proportion that describes the vertical axis in Figure 44. Over the past 15 years mathe- matics, physics, chemistry, engineering, the agricultural sciences, and the humanities have been donor fields, inasmuch as a substantial portion of those who earn baccalaureates in these fields switch to other fields for their doctorate degrees. Receptor fields include the earth sciences, biosciences, and education. This leaves a third group in which the switches for the total of the 15-year period are approxi- mately in balance: psychology, the social sci- ences, the medical sciences, and the professions. Changes over Time Of the various reasons mentioned above for making field switches, the perception of career oppor- tunities is perhaps the one that varies most over time. The time trends in the PhD/BA ratios may reflect market conditions, and the slopes in the curves in Figure 44 would seem to be most readily interpreted in terms of the condition of the market—academic and nonacademic—over the

62 EMP Fields Bio-Behavioral Fields 180 r- 160 140 o £ 2 120 < ac 100 Nonscience Fields Education Earth sciences, biosciences, and education are strong "receptor" fialdi; mathematics, chemistry, engineering, agricultural sciences, and humanities are "donor" fields Biosciences Earth Sciences Professions 80 60 1960- 1964 Medical Humanities I I J 1965- 1969 1970- 1974 1960- 1965- 1970- 1964 1969 1974 YEAR OF DOCTORATE 1960- 1964 1965 1969 1970- 1974 SOURCE: NRC, Commission on Human Resources FIGURE 44 Ratio of doctorate degrees in each field to BA degrees in that field held by PhD's of 1960-1974. past 15 years. Thus, physics, chemistry, mathe- matics, the biosciences, and psychology show declining trends. The fields with ascending curves are the earth sciences, the agricultural sciences, and the medical sciences; perhaps the employment and career opportunities in these fields have been relatively better than in the remaining groups. Engineering, the social sci- ences, and the professions have been relatively stable in their PhD/BA ratios. The heterogeneity of these three fields may well explain their "middling" position; subfields may well show ascending and descending curves. SEX AND FIELD DIFFERENCES The PhD/BA ratios in Figure 44 are for both sexes combined and reflect predominantly, of course, the situation with respect to the men. Data for women PhD's are also given in Table 23, and it is easy to see that they are in many cases different from those for men. The ratios vary much more. That is, the ratios for the donor fields are lower, in general, for the women than the men, the exceptions being agricultural sci- ences, psychology, and the humanities. The question may be raised as to the factors that are most important in determining the long- term differences between the donor and receptor fields—averaging across extended time periods to rule out the effects of market fluctuations. Perceived or demonstrated ability to compete is probably one of the more important factors. We might expect the more demanding fields to "donate" their less successful students to another field where their chances of graduation would be

63 O Q or D 5 u a % UJ U OL g inn Math Physics Chem Earth Engr FIELD OF BACCALAUREATE DEGREE Agr Med Bio Psy Soc Sc Hum Prof Educ IIAI Earth ~~ Engr Educ Phys — Chem Bio Psy — Agr SS Hum U Math — Although each field is its own best baccalaureate Med Prof source, the "recruitment patterns" vary strongly from field to field Bio Bl° Educ — Educ Educ Bio Educ Educ Educ SS in Chem 1 U _ Engr Educ Hum Is SS Educ Hum SS Erwr PhVS Med Prof Prof Hum Phys . Bio Agr Psy Math Educ Educ Psy Psy Hum Earth SS *?"h Bio p'of Educ Chem Agr SS Psy SS Psy Bio Psy Engr SS 2 Pro! Eng, SS Med — Psy — Prof Educ Chem Hum Prof Earth Hum Bio Chem Hum E"th Hum Bio 1 Agr SS Med Chem SS Bio Agr SOURCE: NRC. Commission on Human Resources FIGURE 45 Relative frequency of PhD field at discipline destinations for various BA field sources. better. The overall pattern of donor and recep- tor fields seems to fit this concept reasonably well. For a more detailed analysis, particularly with respect to the sex differences, it would be necessary to examine the field-to-field changes, by sex and cohort, which can be provided by the Commission on Human Resources. For the present, it will probably be most useful to consider data first for both sexes combined, and for the entire 15-year period, as shown in Table 23. MATRIX OF FIELD-TO-FIELD SHIFTS A matrix of the shifts from each baccalaureate field to each doctorate field, in percentage terms, with source fields (baccalaureate) on the vertical axis and destination fields (PhD) on the horizontal axis, is provided in Table 24. To show these changes more graphically, two charts have been prepared, one from the standpoint of the baccalaureate fields as sources (Figure 45) and the other from the standpoint of the PhD fields that draw selectively upon these sources (Figure 46). We will examine the data of Figure 45 first. Because the majority of baccalaureates in each field remain in that field (with two minor exceptions, which will be noted), while many fields take up small percentages, it has seemed appropriate to represent the scale of PhD desti-

64 z rOCOOOCMOrHCMCM^^CO r- m H CM 0 *T £ •H rH m ^ rH CM (M (M sO rH in ft m s rH O * "T O O O O O O*HO O O O O O -H O T O o o o in O 1 rH 0 o n o e o CM 3 0 TJ U •H 41 rH rH rH rH (M rH (M 00 ^ rH ft 10 H Ol d 01 1 1 g O ul On (w rH (M ^> 1 B 01 0 in X 4J •H sO 1^ m CO rH r* 0* U -T n B u •H rH m jj i 0 Ul .^ T1 rH rH o** rH 1 n 0 in o Ul lences 0-5 IN. sO rH 1 r* r- 00 CO o o •H o rH rH CM CM ps 10 O d CM CM rH ffl Ul 01 rH •H 1 TJ rH -H 0) rfl U X U Ul U CO I B rH ^ **7 (M -H O CO -H m m m rH H 3 U rH .H nl i 41 ^f O in m & p U B HI in rs H d rH rH percentage 1 B rH m CO •H rH O & B intMCO^lrHrHCMOOO«7OOO OOO OOOOO rv QO O O o r* d in r- rt H rH H 0 01 41 en i HJ U U U3 B 0 QO so o o O rH rH i? 'MCOC^r*tM^Of*lrHsDCMsi)COin'r7OrHrHrH I | ^O*M co r* in in s n o o o ^ m ^ (M in d r* 'centage; •H sO 03 rH tn U irces. -H O n rH CM r* Oield: x: 0 0 O m T CO in & o 0* fs. IX rH rH • 41 Ul ^ O 00 in Oft r: >hD FIELD SWITCHING, 1960 a (M rn m o rn number of cases; H = horizon CE: NRC, Commission on Huma £ m rH Ul 0) U > X > X 0 H X c .H tn u v n irt W O V 8C U <H « C 0) Ul CtTfB-HU l Q) U l LE24 Ul .H >.-H.H3o)OtJ*OO;0 4J V4Uk44J C O tfl -H *H flUl*JUlQ)-HrH0)rH 4J 0) EUU l 0) 3 *J .H O — ' -H (fl 1 T3 rH m T 0) i i ^ I CO O

FIELD OF DOCTORATE 100 50 O _l UJ X u UJ U oz £ S cc i — u O 10 Math Phvxcs Chem Earth Engr Agr Med Bio Psv SocSci Hum Prof Educ Chem *** — Ph Hum Math Earth Agr Psy ~ Bio SS Educ - Med Prof Except in medical sciences, the professions, and education, most eventual PhD's stay in their baccalaureate fields for the doctorate. but the patterns are varied Bio Hum Hum - Chem Hum SS Engr Bio Chem Hum Engr — Phys — Engr Agr Prof Engr SS Psy Phys SS Prof Math Engr Chem Educ SS Educ Educ Math Bio Math Math Educ Bio Med Psy ~ Chem Agr Educ Hum Prof ^ Educ Prof Med Math Phys Hum Bio P.T Math Hum Hum SS eauc SS Math Chem Chem Chem Med P«V Engr Engr Math Agr Hum Bio Agr Engr f'°' Engr Chem -Math M*ri — SOURCE NRC. Commission on Human Resource! FIGURE 46 Relative frequency of various BA source fields, for each PhD field. nations in logarithmic form, to spread out those that would otherwise be too close together for legibility. Thus, in the case of mathematics, in column 1 of Figure 45, mathematics as a PhD destination appears near the top but still is only at the 56 percent point. Moving down the column, we note that about 15 percent of mathe- matics baccalaureates take doctorates in educa- tion, about 7 percent in the social sciences, 5 percent each in physics and engineering, 3 per- cent each in the humanities and biosciences, 2 percent each in psychology and the professions, and 1 percent each in the earth sciences and chemistry. In a similar manner, one may look down each succeeding column and note the percentage who remain in the field of undergraduate major and the percentage who switch to other fields. By reference to Table 24, a more exact statement of the percentages is available. Mathematics, as it turns out, is one of the lowest of the baccalaureate fields in retention of its gradu- ates through to the doctorate. Alternatively, it can be described as one of the best as a basis for getting a PhD in a variety of fields. High proportions of mathematics majors go into other fields, partly as a function of the trans- ferability of skills, and partly as a function of the relative size of the various fields. The contrasting sizes of the fields of earth sci-

68 ences and chemistry, both near the bottom of the mathematics column, brings the latter considera- tion into focus. Looking at the other fields of baccalaureate as contributors to their own fields at the PhD level, one sees that the earth sciences and education retain a high proportion (over 80 per- cent) through to the doctorate. Engineering (79 percent), the biosciences (75 percent), physics and psychology (73 percent each), and chemistry (69 percent) are intermediate, and the other fields are much lower in retention rate. It must be recognized that "retention rate" is a function of the breadth of the field and that in important ways fields designated here are not uniform in "breadth," although there is no way that one can define breadth objectively and quan- titatively. The transferability of skills learned in undergraduate training is an important factor. No doubt the ubiquitousness of the need for mathe- matical skills accounts in large part for the number of persons leaving mathematics as a spe- cialty and moving to other fields where their mathematics skills can be utilized. Another fac- tor in this particular case is the fact that mathematicians per se have little other than the academic area for employment, whereas by switching, they find more fields of application. The relatively high proportion of math BA's going into education undoubtedly represents a recognition that opportunities to teach mathe- matics and do research in mathematics are limited at the university level. If one majors in educa- tion, more opportunities open up in colleges, junior colleges, and even in high schools—perhaps for those with teaching skills and interests but less aptitude for research in mathematics. Physics as a baccalaureate source field con- tributes, not unexpectedly, to engineering about 8 percent of its graduates. Bioscience (4 per- cent) comes next, in large part, no doubt, because of the development of the growing field of biophysics. Mathematics and physics have a great deal of overlap in terms of skills learned and required, and mathematics absorbs almost 4 percent of physics majors. Other destination fields include the earth sciences and education (3 percent each) and the social sciences and humanities (1 percent each). Chemistry contributes a high proportion of its baccalaureates to the biosciences (18 per- cent) —a tribute to the size of the biochemistry field. Almost 4 percent of BA-1evel chemists go into education and 2 percent or fewer into engineering and medical sciences; 1 percent or less enter other fields. The earth sciences, as noted earlier, have the highest retention rate, but still contribute 4 percent of their graduates to education, 3 percent to the social sciences, 2 percent each to the biosciences and engineering, and 1 percent to the humanities. Engineering and physics, as noted earlier, have a reciprocal relationship, and physics is the major nonengineering destination field (5 per- cent) for engineering graduates; approximately 3 percent go into mathematics, chemistry, and the professions and between 1 percent and 2 per- cent into four other fields: earth sciences, biosciences, social sciences, and education. The agricultural sciences have an understand- ably close relation to the biosciences: 22 per- cent finish with bioscience PhD's. The social sciences get 6 percent, perhaps because of a cer- tain degree of ambiguity regarding the classifi- cation of agricultural economics. Education also claims 6 percent—undoubtedly primarily as teachers of agriculture. No other field takes over 2 percent. The medical sciences contribute 12 percent of their number to chemistry as a PhD destination field, probably concentrated mainly in Pharmaceuticals. Bioscience gets 23 percent; education, 13 percent; and psychology, the agri- cultural sciences, and the social sciences, 3 percent each. The net result is that only 41 per- cent of those with baccalaureates in the medical science fields take doctorates in this field. A certain degree of ambiguity attends this finding, however, since the coding of foreign pre-PhD degrees in this field involves some uncertainty and in the early 1960's MD degrees were coded here in a combined "baccalaureate and first pro- fessional" category. The biosciences have a high retention rate, but still about 8 percent go into education at the doctorate level, followed by 5 percent each to the agricultural sciences and the medical sci- ences, and 2 percent to psychology. Psychology, as might be expected, is closely related to education; about 18 percent of psychology majors end up with education doctorates. About 3 per- cent go into the social sciences, and 2 percent each into the humanities and the professions. The social sciences contribute about as many of their graduates to education (18 percent) as does psychology but a much higher proportion (7 percent) to the humanities, 6 percent to the professions, and 4 percent to psychology (an al- most even exchange). Of the humanities baccalaureates, over 20 percent finish in education, about 7 percent in the social sciences, 5 percent in the professions, and 4 percent in psychology. The "professions" are a very diverse set of fields, including theology, business administration, home economics, law, journalism, speech and hearing sciences, social work, and library science. The PhD field destinations are also diverse, including only 40 percent to the "professions," 25 percent to edu- cation, 17 percent to the social sciences, 10 percent to humanities, and 4 percent to psychol- ogy. Education, as noted earlier, has a high retention rate, but still 6 percent of education majors complete doctorates in the humanities, and about 3 percent each in the biosciences, the social sciences, and psychology. The psychology-education exchange is predominantly a one-way street. There is an additional row on the baccalau- reate side of Table 24 that is not shown on the chart of Figure 45. That row is for unknown baccalaureate fields. These range from about 2.5 percent to a little over 5 percent entering each PhD field, with the exception of the medi- cal sciences. As noted earlier, there is some ambiguity about the medical sciences at the "baccalaureate" level, and this is probably the

67 reason for the deviation of the medical sciences from all the others in the row for "baccalaure- ate field unknown." BACCALAUREATE SOURCE FIELDS As mentioned earlier, one may look at the field- switching phenomenon from an entirely different perspective: backwards from the doctorate fields to see what source fields contribute to each of the PhD disciplines. This is shown in diagram- matic fashion in Figure 46. Here it is immedi- ately apparent that each field is its own best supplier by a much higher margin than one would expect from the data of Figure 45. Mathematics supplies three out of four of its own PhD's, tak- ing 10 percent from engineering, 5 percent from physics, and 2 percent each from the humanities and education. The transferability of skills is undoubtedly a major factor in this pattern— fields other than engineering and physics are unlikely to require the development of mathemati- cal skills sufficient to permit their graduates to switch to mathematics as a doctorate-level discipline. A few make it, but undoubtedly because of special interests and choice of elec- tives, rather than by reason of required training. A similar and reciprocal set of relationships is found for the source fields for physics. Engineering contributes about 12 percent, mathe- matics about 4 percent, and chemistry and the humanities 1 percent each. Chemistry is even higher than mathematics and physics in the extent to which it draws on its own baccalaureate field for future doctorate recipients. It does, how- ever, draw also on engineering (4 percent), medical sciences (2 percent), biosciences (1 per- cent) , and the humanities (1 percent). The earth sciences, which had the highest retention rate from BA to PhD, is lower than any other natural science field as a source field for its own doctorates—no doubt because, as an undergraduate field, it is very small. It draws extensively from the other sciences, physics (9 percent), engineering (7 percent), math, the biosciences, and chemistry (about 4 percent each), and less on other fields (humanities, 2 percent; social sciences, 1 percent; agricultural sciences, 1 percent). Engineering is highly self-contained, but does draw about 4 percent of its doctorates from physics, 2 percent from mathematics, a little less than 2 percent from chemistry, and about 1 percent from the humanities. Agricultural sciences as a PhD field draws about three-fourths of its members from under- graduate majors in agricultural sciences, but it also draws heavily on the biosciences (11 per- cent) . Education and chemistry each contribute 3 percent, and the medical and social sciences about half of that. The ambiguities in the medical sciences as a first-level field do not apply at the doctorate. This field includes veterinary medicine, parasi- tology, pharmacology, pharmacy, pathology, envi- ronmental health, public health and epidemiology, hospital administration, and nursing, as well as "other" and "general." It is not surprising, therefore, that the source fields for the medi- cal sciences are diverse: 11 percent come from chemistry, 23 percent from the biosciences, 3 percent each from the agricultural sciences and the humanities, 2 percent each from psychology, the social sciences, and education, and 1 per- cent each from physics, engineering, and the professions. The biosciences as a doctorate field draw heavily from the undergraduate fields of chemis- try (15 percent) and agricultural sciences (8 per- cent) and less from others—3 percant each from medical sciences and education and 2 percent each from physics, engineering, and the humanities. Psychology draws a surprisingly high 10 percent from the humanities, 5 percent from the social sciences, 4 percent from education, 3 percent from the professions, and 2 percent each from the biosciences and mathematics. The social sci- ences draw heavily (13 percent) from the humani- ties, somewhat less so from the professions (7 percent), 4 percent from mathematics, 3 percent each from the agricultural sciences and educa- tion, and 2 percent each from engineering and psychology. The humanities draw 4 percent of their PhD's from the social sciences, an equal percentage from education, 3 percent from the professions, and not over 1 percent from any other field; 79 percent of the humanities doctorates had undergraduate training in the same field group. The professions, by contrast, are a very miscel- laneous set, and their undergraduate sources show it. The humanities contribute 22 percent; the social sciences, 13 percent; engineering, 8 percent; education, 4 percent; psychology, 3 percent; and mathematics, 2 percent. Education is also very broad in its undergraduate origins: humanities, 20 percent; social sciences, 8 per- cent; psychology, 6 percent; professions, 5 per- cent; mathematics, 4 percent; biosciences, 4 percent; chemistry, 2 percent; and agricultural and medical sciences, 1 percent each. THE GEOGRAPHY OF DOCTORATE ORIGINS The major change in the geography of doctorate production has been the rise of the South and Rocky Mountain States in the output of PhD's. In this section we look at these data from a different perspective—the regional interchanges between the baccalaureate and doctorate degrees and, going farther back, the regional inter- changes from the level of high school graduation to doctoral graduation. The map in Figure 47 shows the states in each region, and the accom- panying table (Table 25) shows the 1970 popula- tion in each region. One of the simpler ways of looking at the data of regional interchanges is to consider the ratio of the number of doctorate-bound baccalau- reates a region produces to the number of doc- toral degrees granted in that region. One may think of this ratio as a donor/receptor ratio, since all regions "give" students at one level to all other regions and "receive" students from all regions for graduate education. If this giving and receiving were equal, the ratio would be 1.00. If a region gives more than it receives

TABLE 25 DONOR-RECEPTOR RATIOS' AT TWO EDUCATIONAL LEVELS, BY SEX, FOR EACH U.S. REGION, 1960-1974 Region High School to PhD Men Women Total Baccalaureate to PhD Men Women Total New England 0.84 0.81 0.83 1.12 1.07 1.11 Middle Atlantic 1.40 1.24 1.37 1.16 1.07 1.15 East North Central 0.85 0.86 0.85 0.88 0.91 0.88 West North Central 1.22 1.31 1.23 1.21 1.27 1.22 South Atlantic 0.84 0.89 0.85 0.84 0.88 0.85 East South Central 1.26 1.40 1.28 1.28 1.32 1.29 West South Central 1.08 1.20 1.10 1.08 1.17 1.10 Mountain 0.83 0.72 0.82 0.91 0.75 0.89 Pacific 0.79 0.77 0.79 0.84 0.85 0.84 Donor regions are those with ratios over 1.00; receptor regions have ratios under 1.00. East South Central West South Central Mountain Pacific TOTAL US. Sates in Each Rej.on 1. New England: Maine, Vtrmont, New Hampshire, Massachusetts, Rhode Island, Connecticut 2. Middle Atlantic: New York, New Jersey. Pennsylvania 3. East North Central: Ohio, Indiana, Illinois, Michigan, Wisconsin 4. West North Central: Minnesota, Iowa, Missouri, North Dakota, South Dakota, Nebraska, Kansas 5. South Atlantic: Delaware, Maryland, D.C., Virginia, West Virginia, North Carolina, South Carolina, Georgia, Florida 6. East South Central: Kentucky, Tennessee, Alabame, Mississippi 7. West South Central: Arkansas, Louisiana, Oklahoma, Texas 8. Mountain: Montana, Wyoming, Colorado, New Mexico, Arizona, Utah 9. Pacific Washington, Oregon, California, Alaska, Hawaii (plus Puerto Rico and Panama Canal Zone) 1970 Population by Census Region (in thousands) New England Middle Atlantic East North Central West North Central South Atlantic 11,842 37.199 40.252 16.319 30.671 12.803 19,321 8.282 26^23 203,212 SOURCE: NRC, Commission on Human Resources FIGURE 47 The nine census regions of the United States.

69 TABLE 26 TIME CHANGES IN DONOR/RECEPTOR RATIOS AT TWO EDUCATIONAL LEVELS, 1960-1974 High School to PhD Baccalaureate to PhD 1960- 1965- 1970- 1960- 1965- 1970- Region 1964 1969 1974 1964 1969 1974 New England 0.77 0.82 0.88 1.01 1.13 1.15 Middle Atlantic 1.26 1.37 1.43 1.06 1.15 1.18 East North Central 0.81 0.87 0.86 0.84 0.89 0.89 West North Central 1.23 1.26 1.21 1.21 1.25 1.21 South Atlantic 0.93 0.84 0.84 0.93 0.84 0.84 East South Central 1.60 1.31 1.18 1.63 1.29 1.20 West South Central 1.21 1.12 1.05 1.22 1.11 1.05 Mountain 1.14 0.84 0.74 1.25 0.90 0.81 Pacific 0.76 0.74 0.83 0.81 0.79 0.89 SOURCE: NRC, Commission on Human Resources. from other regions, its ratio is higher than 1.00; if it grants more doctorates than it con- tributes to other regions at the undergraduate level, its ratio would be lower than 1.00. We can thus think of the regions with high ratios as donor regions and those with lower ratios as receptor regions. In these very simplified terms, the regions with older, well-established doctorate- granting institutions are the prime receptor regions. This group includes the East North Central States, the South Atlantic region, the Pacific Coast, and, for the most recent decade, the Mountain States. Prior to 1965, the Mountain States were in the donor category, but they have made a dramatic shift and are now in the receptor category. No other region has shifted across the balancing line of a 1.00 ratio, although the southern states have moved strongly in the same direction. Rather surprisingly, New England is in the donor category—apparently because its excellent undergraduate institutions attract many high school graduates from other regions, so that it donates more doctorate-bound baccalaureates than it graduates PhD's. At the high school to PhD interchange. New England exhibits a sharp contrast to its perfor- mance at the baccalaureate level. Because of its relatively small population, it produces fewer high school graduates that eventually attain the doctorate than it does either baccalaureates or doctorates. It is the only region that shifts from the receptor to the donor category between the high school and undergraduate levels of edu- cation. Tables 25 and 26 provide the information with respect to the relevant ratios. Table 25 shows the data for the entire 1960-1974 period, by sex, for both the high school/doctorate shifts and the baccalaureate/doctorate shifts. Table 26 shows the time changes, by 5-year cohorts, at both levels, for the combined total of both sexes. Tables 27 and 28 show all the regional interchanges for the entire 1960-1974 period. More detailed tables, by field, sex, and time period, are available from the Commission on Human Resources. Note that foreign areas are excluded in Tables 25 and 26 but given in Tables 27 and 28. Sex differences in the donor/receptor ratios are quite distinct although usually not as dra- matic as the changes over time. The patterns of sex differences are similar at the high school and baccalaureate levels, although the magnitude of the differences, and the range of the donor/ receptor ratios, is greater at the high school level than at the baccalaureate level. The regions in which the HS/PhD ratios and the BA/ PhD ratios are higher for men than for women are the Rocky Mountain States and the New England and the Middle Atlantic States. In the other five regions—the Pacific Coast, the South Atlantic States, and all the Central State re- gions, the ratios are higher for women than for men. That is, the tendency to "donate" rela- tively more men than women is stronger in the central regions and the Pacific Coast, while the East Coast and the Rocky Mountain States have a stronger tendency to "donate" women des- tined for the doctorate degree. This may be in part a result of field differences that have not been examined, since there are substantial sex and regional differences in the field mix at both the baccalaureate and doctorate levels, and they may be related in such a way as to produce the sex differences that have been noted in the donor/receptor ratios.

71 REGION OF BACCALAUREATE 100 50 OC o o o 0 w tr X o LU o z O HI rr i o ul O K LU O. 10 New England (NE) Middle Atlantic IMA) East North Central (ENC) West North Central (WNCI South Atlantic ISA) East South Central (ESC) West South Central (WSC) Mountain Statet Pacific & Insular (Pac) Foreign - MA ENC SA WSC (Mini Pac NE Geography has its "donors" too. each region is its own favorite source of baccalaureates for its eventual PhD's WNC ESC Mtn ENC MA ENC SA Pac MA Pac ENC ENC ENC ENC ENC P«r Nr- SA MA MA WSC ENC ENC NE SA WNC — SA Pac Pec Mtn WNC WNC MA SA Mtn - Pac SA NE MA WSC ESC WNC Pac MA NE NE MA WSC SA Pac ESC. Mtn WSC - Mtn WSC WNC MA SA WNC SA Mtn WNC WMC WSC NE WNC PK NE NE NE — Mtn Mtn Mtn Mtn WSC ESC WSC WSC ESC ESC ESC ESC ESC ESC SOURCE: NRC, Commission on Human Resources FIGURE 48 Graph of baccalaureate regional "donor" percentages. REGIONAL DONOR PERCENTAGE DIAGRAMS To provide a visual picture of the regional inter- changes. Figures 48, 49, 50, and 51 show the individual region-to-region percentage changes at both the baccalaureate-to-doctorate levels and the high-school-to-doctorate levels. At both levels, each region is considered from both the donor and receptor points of view; hence there are four figures in all. By examining these four figures (or the data of Tables 27 and 28) it is possible to develop a sense of the interregional interchanges that are occurring to move people from the high school and baccalaure- ate levels to the doctorate level. It should be noted, in examining Figures 48 through 51, that the vertical scale is logarithmic. This was done to bring into sharper focus the smaller

72 REGION OF HIGH SCHOOL GRADUATION 100 60 10 g 5 New Middle East North West North South Eest South West South Mountain Pacific US TOTAL England Atlantic IMAI Central (ENCI Central (WNCI Atlantic (SA) Central IESC) Central IWSCI State* & Insular IPac) Foreign INE) From high ichool to PhD the regional interchange* are heavier then from BA to PhD IMtn) — but have similar patterns — MA ENC SA WSC Pec — WNC ESC Mm NE ENC ENC MA ENC Pec MA SA Pec MA ENC ENC ENC ENC ENC ENC Pec SA NE SA PAC MA WSC ENC NE SA Pec SA WNC PK Mm WNC NE MA WNC Mtn MA Pec WNC SA WSC NE Pec - SA WSC MA ESC Pec MA WNC MA NE WSC Mtn NE 5A ESC WSC Mm WSC Pec WNC SA WNC SA WNC WNC NE WNC NE MA NE Mtn ESC Mtn Mm WSC Mtn Mtn NE WSC WSC WSC ESC ESC ESC ESC ESC ESC ESC SOURCE: NRC. Commiaion on Human FtetourcM FIGURE 49 Graph of high school regional "donor" percentages. percentages that characterize the interregional changes, in contrast to the "in-breeding" ratios (the diagonal data of Tables 27 and 28). Each region is, by a good margin, its own best source of doctorates—with the single exception of New England at the high school level. New England gets more doctorate-bound high school graduates from the nearby Middle Atlantic States than it does from its own high schools. We will begin an examination of Figure 48— the baccalaureate donor percentage diagram--with the column for New England. Here we see that New England contributes about 37 percent of its own doctorates, the smallest self-contribution figure for any of the regions. It contributes 21 percent of its BA's to the contiguous Middle Atlantic region, and 15 percent to the East North Central region. Next in order is the Pacific region, distant as it is geographically, closely followed by the nearby South Atlantic region. Far down—below 4 percent—are the other four regions, all more distant and with fewer vigorous doctoral institutions. In a similar manner the donor characteristics of the other regions may be examined. It is noteworthy that for each of the regions, its contribution to its own doctor-

73 REGION OF DOCTORATE 100 50 K o U at u, O O ui K o P 10 < z o CC o in b tv «/> O 5 o Ul cc z LU U cc 111 CL New Middle East North West North South East South West South Mountain Pacific England Atlantic Central Central Atlantic Central Central States & Insular (NE) (MA) (ENC) (WNC) (SA) (ESC) IWSC) (Mtn) (Pac) - Each region's PhD's earn their BA's — primarily in the same region - MA WSC — ENC WNC SA ESC Pac NE Mtn - - MA Foreign Foreign Foreign Foreign ENC Foreign MA SA WNC ENC ENC MA Foreign ENC WSC Foreign Pac ENC NE Foreign ENC WNC NE ENC Foreign WNC MA ~ Pac MA ESC ENC MA NE WSC Mtn NE WNC SA SA SA, Pac WSC MA r"^*p SA - Pac WSC WNC WNC MA WNC Pac WSC ESC Mtn Pac Pac SA - WNC NE SA Mtn NE SA - wsc Mtn ESC NE NE WSC Mm WSC. Mtn Mtn Pac ESC ESC Mtn ESC ESC SOURCE: NRC, Commission on Human Resources FIGURE SO PhD regional "receptor" percentages from each region of baccalaureate. ate production ranges somewhat above or below the 50 percent line but that no region contrib- utes more than 21 percent of its baccalaureates to any other single region. Typically, the interchanges that rank highest are between near- by regions but this is not always the case, par- ticularly with regard to the West Coast. Finally, to the right is a column for the total of all foreign regions of baccalaureate. The foreign regions, taken as a totality, contribute one--

74 REGION OF DOCTORATE 100 50 0 o o 05 I u— o o III K id z O o OJ ac u. O t- rr W a. 10 1 New Middle East North West North South East South West South Mountain Pacific U.S. TOTAL England (NE) Atlentic (MA) Central (ENC) Central (WNC) Atlantic (SA) Central (ESC) Central (WSC) States (Mtn) & Insular (Pac) - ENC WNC SA ESC i— WSC Mtn Pac MA ^ E xcept for New England (by a hair) each region's NE ^ F hD'j originate primarily in its own high schools MA - MA Foreign Foreign Foreign Foreign MA Foreign ENC Foreign SA Foreign WNC ENC ENC Foreign Pac Foreign MA ENC ENC WSC ENC - Foreign MA WNC — MA Pac — ENC WNC ENC MA WNC SA NE ENC WSC -SA Pac ESC MA ESC WSC WNC Mtn NE SA WSC Pac MF SA Pac NE WSC WNC - WNC WNC Mtn Pac Mtn SA NE ESC WSC SA WNC ESC SA Pac Pac Mtn NE WSC WSC Mtn NE - NE Mtn ESC Pac NE ESC WSC Mtn ESC Mtn Mtn ESC ESC SOURCE: NRC, Commission on Human Resources FIGURE 51 PhD regional "receptor" percentages from each region of high school. fourth of their number to the East North Central region, one-fifth to the Middle Atlantic, one- sixth to the Pacific region, and less than 10 percent to each of the other regions. Going back one educational level, we see, in Figure 49, the analogous contributions of each region of high school graduation to the several doctoral regions. New England contributes 35 percent of its doctorate-bound high school grad- uates to itself, 21 percent to the Middle Atlantic States, 16 percent to the East North Central States, and less than 10 percent to each other region. The pattern is very similar to the baccalaureate donor pattern but not exactly so. In comparing the regions at or near the bottom of the page, it may be noted that the

76 East South Central region, although it is typi- cally low except for the other southern regions, is never off the scale, as it is in the case of the baccalaureate origins. At the far right, beyond the foreign origin column, is a column for the total United States. What this column tells is the doctoral destinations for the entire U.S. doctorate-bound high school graduation popu- lation. The regions are, therefore, shown in terms of their relative outputs of doctorates of U.S. origin, which can be compared with their relative standing in output of doctorates from foreign secondary school sources, shown in the adjoining column. REGIONAL RECEPTOR PERCENTAGE DIAGRAMS The data of Table 25 can be examined in graphic form in Figures 49 and 50. Turning first to Figure 50, we see the pattern of baccalaureate receptor percentages—the percentage of each regions's PhD's that have been received from each of the regions of baccalaureate origin. New England receives 35 percent of its PhD's from New England undergraduate sources, 20 percent from the Middle Atlantic colleges and universi- ties, 15 percent from foreign sources, a bit over 10 percent from the East North Central region, and so on down the column. The Middle Atlantic States, shown in the second column, get half their doctorates from Middle Atlantic undergraduate schools, 15 percent from foreign sources, and less than 10 percent from any of the other regions. Each of the regions, as we scan across the diagram, is seen to be its own best undergraduate source, with the proportions ranging from about one-third to one-half of the region's doctorates. Foreign sources range downward from about 16 percent to about half of that for each of the regions of PhD. In no region except New England does another U.S. region contribute more than 15 percent to a region's PhD output. The pattern of secondary school sources for the various receptor regions, shown in Figure 51, is similar to that of Figure 50 but with some subtle yet pervasive differences. For example, the foreign area contributions, region by region, are higher at the high school than the baccalau- reate level, because some people with secondary education in foreign countries come to the United States for their undergraduate education. As mentioned earlier, the East South Central States never run off the bottom of the chart at the high school level, as they occasionally do at the baccalaureate level. The pattern of these differences suggests that a more intensive study than is possible in this book may well be re- warding. Such a more intensive examination, should scholars in this area be interested in pursuing it, could follow the movement, by sex and field, from high school to college to gradu- ate school and eventually on to employment. Many of the data necessary for such a study were pub- lished in the book Mobility of PhD's, published by the NAS in 1971; an update that takes into consideration the rather profound changes during the late 1960's and early 1970's—the period of "the new depression in higher education"—might be very revealing. It might be particularly revealing if it would take into account the edu- cational backgrounds from which the migrants and nonmigrants come, the nature of the jobs they eventually take, and some measures of career achievements. The necessary data for further studies of this nature, by university researchers or others, are available at cost from the DRF and Comprehensive Roster of the Commission on Human Resources.

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