Women, however, did not achieve the rank of full professor in the same proportions as men. At 5 years or less since the doctorate, women actually had a slight edge in the full professor category (2 percent, compared with 1 percent for men). For the cohort 6 to 15 years since degree, the proportion of men who were full professors was nearly twice that of women (16 and 9 percent, respectively). The gap widened with time and after 25 years, only 55 percent of women were full professors compared with 78 percent of men. It should be noted that these comparisons are made by years since doctorate, rather than years in the work force. Women are likely to have more career interruptions than men, which could account for some of the observed disparities.