Richard Lester Solomon, October 2, 1918October 12, 1995 | By Robert A. Rescorla | Biographical Memoirs

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Richard Lester Solomon
October 2, 1918 October 12,
1995
By Robert A. Rescorla
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RICHARD LESTER SOLOMON was the
complete university professor. He cared deeply about
the creation and evaluation of ideas. He loved the process of sharing
these ideas with his colleagues and students. And he glowed with
enthusiasm when he had the opportunity to foster the development of
ideas in others. Dick Solomon was an experimental psychologist whose
research interests ranged broadly around the theme of learning and
motivation. He made major contributions to many areas, but he is
especially known for his work on avoidance learning and opponent-process
theories of motivation. For that work he received a wide assortment of
awards and honors. Of equal importance, especially to him, he trained a
whole generation of research psychologists, literally populating an
important subfield with most of its leaders. Most importantly of all, he
was a warm and supportive person, whose affection and wisdom
strengthened every person and institution with which he had contact.
Dick was born in Boston in 1918, into a family whose
mother had high moral values and whose father was a hard-driving CPA. He
described his family life as orderly and intense, with an emphasis on
manners, achievement, and personal responsibility. The home environment
emphasized the importance of reading and debate.
He attended public schools in Newton and Brookline,
graduating with a spotty grade record marked by high grades from
teachers he liked and low grades from those he disliked. One especially
well-liked teacher, Tyler B. Kepner, demanded analytic thinking in the
context of teaching United States history. It was Kepner's
encouragement, and his high recommendation, that was critical to Dick's
applying to college and matriculating at Brown.
Although his high school interests had tended more
towards the humanities, Dick was drawn to economics and psychology at
Brown, eventually completing a joint major. He carried out an
undergraduate honors thesis directed by Joseph McV. Hunt, which earned
him a summa cum laude degree in 1940. His eventual decision to focus on
psychology was heavily influenced by the quality of the members of the
Brown psychology department at that time, people such as Walter Hunter,
Harold Schlosberg, Donald Lindsley, Carl Pfaffmann, and Lorrin Riggs.
Dick elected to remain at Brown for his graduate
training, working in the laboratory of Harold Schlosberg. His graduate
career was interrupted by the Second World War, during which he served
as a research psychologist in the Office of Scientific Research and
Development. There he worked on perceptual-motor systems for the
defensive weapons systems of the B-29 bomber. At the end of the war Dick
returned to Brown where he received his Ph.D. in 1947.
In 1947 Dick took up an assistant professorship in
social relations at Harvard. He remained at Harvard, becoming an
associate professor in 1950 and a full professor in 1957. In 1960 he was
recruited by Bob Bush to the newly emerging psychology department at the
University of Pennsylvania. At Penn he became the first James M. Skinner
University Professor of Psychology. Dick retired from that department in
1984.
Reflecting the times in which he was
trained, Dick Solomon had wide ranging basic research interests within
experimental psychology. But two themes run through this remarkably
diverse research career: a repeated concern with improving the
sophistication of experimental designs and a consistent desire that the
research be brought to bear on applied psychological problems.
Much of Dick's earliest work dealt with the so-called
"new look" in perception. In the late 1940s and early 1950s it was
popular to suppose that personal motivational variables might produce
distortions leading both to nonveridical perception of such object
dimensions as size and to reductions in the likelihood of seeing
unpleasant events. In the midst of a field full of injudicious claims
based on uncertain methodology, Dick conducted careful systematic
experiments exposing clear parametric relations. As a result of these
experiments, many of the less cautious claims were put to rest.
Beginning in the early 1950s, Dick began the work for
which he is perhaps best known, the systematic study of avoidance
learning in dog subjects. Avoidance learning was a hot topic at that
time, in part because of the puzzle about what maintained the behavior
once it was acquired. In a typical experiment a dog was placed in a
two-compartment shuttlebox. Its task was to jump a barrier in order to
cross to the other side. A warning signal, such as a tone or light or
the raising of a door separating the chambers, alerted the animal that
it had a short period, such as ten seconds, in which to cross to the
other side. Failure to cross within that period resulted in the
application of electric shock to the grid floor of the chamber; that
shock could only be terminated by crossing. However, crossing during the
warning period avoided the shock altogether. Dogs readily learned such a
task and would reliably execute the jumping response trial after trial
without shock, once it was learned. For many, the puzzle was that the
animal appeared to be rewarded by the failure of some event to occur.
Characteristically, there were three aspects to
Dick's approach to this work. The first was careful parametric
investigation of the determinants of avoidance learning. In an era of
demonstration experiments, Dick and his students collected some of the
first really systematic data on avoidance learning. The second was the
development of a theoretical framework which would account for the
behavior in all its richness. For this he turned to the two-process
theory which was being developed by Miller, Mowrer, and others. He saw,
perhaps more clearly that anyone else, that avoidance learning was the
product of two learning processes: a classical conditioning process in
which the warning signal became aversive by virtue of developing a
Pavlovian association with the shock and an instrumental learning
process in which the animal's jumping response was rewarded by the
removal of that aversive warning signal. That theory remains even today
as the core part of current explanations of avoidance behavior. Thirdly,
Dick realized the important clinical applications of avoidance behavior,
and its extreme resistance to being eliminated, for the understanding of
such human pathologies such as phobias.
Out of
this work on traumatic avoidance learning grew three other threads of
Dick's work. The first was the development, with Lucy Turner, of the
so-called transfer paradigm. In the course of their analysis of the
Pavlovian basis of avoidance behavior, they developed a paradigm which
has proved to be of immense power in the analysis of associative
learning. They found that after dogs had been trained to make an
avoidance response to one warning signal, other signals which had simple
Pavlovian pairings with shock would also produce the avoidance behavior.
Of special interest to Dick was the fact that this latter learning
occurred even when the signal was paired with shock at a time when the
animal was fully immobilized by curare. That transfer paradigm remains
one of the major tools used today to identify Pavlovian and instrumental
associations. In the course of developing that paradigm, Dick was
extremely influential in helping the field work through one of its core
distinctions, that between Pavlovian conditioning and instrumental
learning. Second, while conducting transfer experiments, students in
Dick's laboratory discovered the phenomenon of "learned helplessness" in
which an animal that receives uncontrollable shocks subsequently has
difficulty learning to avoid those shocks when given the chance. Again,
the analysis involved careful parametric work, construction of theory,
and attention to clinical application. Third, the study of avoidance
naturally led to Dick's interest in a paradigm which is in some ways its
complement, punishment. During the 1950s and 1960s a combination of
political, scientific, and social attitudes conspired to popularize the
view that punishment was an ineffective way to suppress behavior. Dick
correctly saw that this was an absurd position and said so in his 1963
presidential address to the Eastern Psychological Association. The
impact of that address was immense, leading many laboratories to take up
the systematic investigation of punishment, greatly expanding our
understanding.
Dick's final theoretical
contribution was the development of a broad ranging theory of
motivation, called the opponent-process theory. Building on ideas from
perception, he developed a framework within which to examine strong
emotional effects in terms of their initial consequences for the
organism and the reactions that the organism generates to counter those
consequences. This theory proved to have vast integrative power,
bringing together ideas about such powerful human emotions as fear,
love, and hope. In Dick's hands it also provided the means of
understanding some important psychological aspects of drug addiction,
participation in sports, and thrill-seeking of various sorts.
This array of important scientific work earned Dick
just about every prize and honor that psychology has to offer. He was
awarded the Distinguished Scientific Contribution award of the American
Psychological Association and the Howard Crosby Medal of the Society of
Experimental Psychologists. He was elected to the American Academy of
Arts and Sciences and, in 1968, to the National Academy of Sciences. He
held such honorific offices as president of the Experimental Division of
the American Psychological Association, president of the Eastern
Psychological Association, and chairman of the Governing Board of the
Psychonomic Society. The University of Pennsylvania honored him as one
of its University Professors, and Brown University bestowed on him an
honorary doctorate. Because of wide respect others had for his thinking,
he was asked to edit the field's most prestigious journal, the
Psychological Review.
Influential as Dick
was as a researcher, he was even more influential as a teacher and
mentor. He had a huge educational impact on students at all levels.
Undergraduates flocked to his classes, attracted by his enthusiastic and
articulate lecture style. He was one of those teachers students remember
decades later. His training of graduate students is legendary. Both at
Harvard and Penn he attracted the brightest and best graduate students
and gave them a training which made them the leaders in the field of
elementary learning processes. In 1983 many of the thirty-two students
he trained, together with colleagues he influenced at Penn and Harvard,
gathered in a two-day celebration of Dick's career. Uniformly, they
recalled the combination of intellectual excitement and personal support
which Dick conveyed. Every one of them spoke of Dick's commitment to
fostering their intellectual growth and helping them to become
independent thinkers and scientists. Dick had a way of creating a
setting, providing resources, subtly affecting your thinking, and then
standing back while you grew.
Each student had a
story about how Dick had placed his students' careers first, often
potentially sacrificing his own. My own experience is typical. While I
was a graduate student, Dick and I were writing what we both knew would
be an important theoretical paper on two-process theory. As we handed
the drafts back and forth, something peculiar kept happening: the order
of authorship kept changing. I would give him a draft with him as the
(proper) first author and when it came back from him my own name was
placed first. Thinking that it was a clerical error, I told Dick that he
needed to speak to his secretary so that she got it right. I still
recall his telling me, "She does have it right. I have plenty of
publications and an established career, but you are just beginning. You
need the authorship much more than I." It was this attitude that
resulted in dozens of publications coming out of Dick's lab without his
name ever being listed as an author. So unusual was his generosity that
his grant applications had to have a separate section listing the
publications of his students that resulted from earlier funding; his own
bibliography reflected only a small portion of the work.
Anyone who passed through the University of
Pennsylvania psychology department in the 1960s, 1970s, and 1980s heard
of Dick's research seminar, the weekly meeting of his students. This
exciting discussion was frequently attended by graduate students and
faculty from other labs. It formed the core of the graduate education
for dozens of psychologists. The interactions were broad-ranging and the
arguments often heated. But no matter what the topic, Dick had a way of
finding the essential and good ideas in what everyone said.
Just as the field honored Dick for his research
contributions, it acknowledged his educational role. He was awarded
Sigma Xi's Montie A. Ferst Award for ". . . notable contributions to
motivation and encouragement of research through teaching" and the
American Psychological Foundation's Award for Distinguished Teaching. He
is one of the few people to have won the American Psychological
Association's primary awards both for distinguished teaching and
distinguished scientific contribution.
Dick served
as a role model not only for his students but also for dozens of
professional colleagues. Although he never accepted a major
administrative position, he was the acknowledged intellectual and moral
leader of the Penn psychology department. His commitment to high
intellectual standards, combined with his fondness for others and his
gentlemanly manner, made his opinion the most valued in any discussion
of policy. The tone of civility that he established allowed even the
most potentially explosive of issues to be debated openly and frankly. I
never knew anyone to attribute to Dick any motives other than the good
of the department and the science.
When Dick
retired in 1984, he moved to North Conway, New Hampshire. There he
continued to pursue vigorously his outdoor interests in hiking and
canoeing. He also continued his role as a mentor, actively encouraging
the members of the White Mountain Miler's, a local running club in which
his wife Maggie was active. When I visited him, I would frequently be
taken aside by members of the community to be told of his wonderful
contributions to their lives. When he died in 1995, over two hundred
people from the community attended the memorial service. With the
exceptions of Maggie, his daughters, Janet and Elizabeth, and his
brother, David, those present knew little of his scientific
contributions. But they had been touched by the same qualities of
personal warmth, enthusiasm, and supportiveness that had so guided his
professional research and teaching career. In 1996 the University of
Pennsylvania renamed its psychology building as the Richard L. Solomon
Laboratory of Experimental Psychology. This will memorialize his
scientific contributions. But no building name can capture his human
qualities.
- 1942
- With J. McV. Hunt. The
stability and some correlates of group status in summer-camp group of
young boys. Am. J. Psychol. 55:33-45.
- 1948
- The influence of work on behavior.
Psychol. Bull. 45:1-40.
- 1951
- With D. H. Howes. Work frequency, personal values, and
visual duration thresholds. Psychol. Rev. 58:256-70.
- 1952
- With L. Postman.
Frequency of usage as a determinant of recognition thresholds for words.
J. Exp. Psychol. 43:195-201.
- 1953
- With L. J. Kamin and L. C. Wynne. Traumatic avoidance
learning: The outcomes of several extinction procedures with dogs. J.
Abnorm. Soc. Psychol. 48:291-302.
- With L. C. Wynne.
Traumatic avoidance learning: Acquisition in normal dogs. Psychol.
Monogr. 67: whole number 354.
- 1954
- With L. C. Wynne. Traumatic avoidance learning: The
principles of anxiety conservation and partial irreversibility.
Psychol. Rev. 61:353-85.
- 1956
- With E. S. Brush. Experimentally derived conceptions of
anxiety and aversion. In Nebraska Symposium on Motivation, vol.
4, ed. M. R. Jones, pp. 212-305. Lincoln: University of Nebraska Press.
- 1960
- With L. H. Turner.
Discriminative classical conditioning under curare can later control
discriminative avoidance responses in the normal. Science
132:1499-1500.
- 1962
- With
L. H. Turner. Discriminative classical conditioning in dogs paralyzed by
curare can later control discriminative avoidance responses in the
normal state. Psychol. Rev. 69:202-19.
- 1964
- Punishment. Am. Psychol.
19:239-54.
- 1967
- With R.
A. Rescorla. Two-process learning theory: Relationships between
Pavlovian conditioning and instrumental learning. Psychol. Rev.
74:151-82.
- 1968
- With V.
G. Dethier and L. H. Turner. Central inhibition in the blowfly. J.
Comp. Physiol. Psychol. 66:144-50.
- With M. S.
Lessac. A control group design for experimental studies of developmental
processes. Psychol. Bull. 70:1545-50.
- 1969
- With S. Maier and M. E. P. Seligman.
Pavlovian fear conditioning and learned helplessness: Effects on escape
and avoidance behavior of (a) CS-US contingency and (b) the independence
of the US and voluntary responding. In Punishment, eds. B. A.
Campbell and R. M. Church, pp. 299-343. New York:
Appleton-Century-Crofts
- 1970
- With M. E. P. Seligman and S. Maier. Unpredictable and
uncontrollable aversive events. In Aversive Conditioning and
Learning, eds. B. F. R. Brush, pp. 347-400. New York:
Appleton-Century-Crofts.
- 1974
- With H. S. Hoffman. An opponent-process theory of
motivation. III. Some affective dynamics in imprinting. Learn.
Motiv. 5:149-64.
- With J. D. Corbit. An
opponent-process theory of motivation. I. Temporal dynamics of affect.
Psychol. Rev. 81:119-45.
- 1977
- An opponent-process theory of motivation. V. Affective
dynamics of eating. In Learning Mechanisms in Food Selection,
eds. L. M. Barker, M. R. Best, and M. Domjan, pp. 255-293. Waco, Tex.:
Baylor University Press.
- 1980
- The opponent-process theory of acquired motivation. The
costs of pleasure and the benefits of pain. Am. Psychol.
35:691-712.
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