(1936 – 1997)
American Psychologist


  • Student of:
  • Influenced by: Cronbach, R. B. Cattell, Horn
  • Students: Dan Woltz, Susanne Lajoie
  • Influenced: Phillip Ackerman, Valerie Shute
  • Time Period: Current Efforts


  • University of Virginia, Bachelor’s Degree in Psychology, 1958
  • Purdue University, M.A. and Ph.D. in Psychology, 1960 and 1963 respectively
  • Honorary Doctoral Degrees from the University of Göteborg, Sweden and University of Leuven, Belgium.


  • 1963-1966, Professor of Instructional Media, Purdue University
  • 1966-1996, Professor of Education with a courtesy appointment in the Department of Psychology, Stanford University
  • 1992-1997, Howard H. and Jessie T. Watkins University Professor, Stanford University
  • 1972-1973, Boerhaave Professor of Medical Education, University of Leiden, Netherlands
  • 1983-1985, Liaison Scientist for Psychology in Europe and the Middle East for the U.S. Office of Naval Research in London

Major Contributions

  • Expanded the notion of “aptitude” from being purely cognitive abilities to include motivational and affective characteristics.
  • Developed, with Lee Cronbach, the Aptitude x Treatment Interaction (ATI) formula postulating that individual differences in intellectual ability may be used to tailor educational instruction to optimize learning potential and academic performance

Definition of Intelligence

“Intelligence is part of the internal environment that shows through at the interface between person and external environment as a function of cognitive task demands” (Sattler, 2001).

Ideas and Interests

Richard E. Snow is noted as having been a prominent educational psychologist who dedicated much of his life’s work toward studying human aptitudes and learning environments. In his work, Snow expanded the definition of aptitude from the conventional cognitive-based strategies and abilities, to include conative and affective characteristics – conative being motivational and volitional aspects of learning and affective being temperamental and emotional aspects. He was opposed to the idea that complex cognition could be captured by a handful of rules or that simple cognitive tasks could reflect the importance of real-world learning and performance (Shavelson, Kupermintz, Ayala, Roeser, Lau, Haydel, Schultz, Gallagher & Quihuis, 2002). While aligning with Cattell and Horn’s theory of crystallized and fluid cognitive abilities, Snow “stressed the importance of looking at individual differences in cognitive processing and analyzing these processes in relation to variations in environmental affordances to develop a person-situated interaction theory of intellect” (Cronbach, Shavelson, & Shulman, 1997).

His coinciding “aptitude-complexes” theory accounted for the interplay between an individual’s personal aptitudes (e.g. experience, motivation, ability, knowledge, and regulatory processes) and situational demands which interact to determine performance. Successful task performance then, is the result of a match between an individual’s personal aptitudes and the situational demands surrounding the task. Over time, these dynamic relationships may change as new aptitudes are applied and/or the tasks altered.

Advocating the need to take a holistic approach to understanding the diverse needs of learners, his aptitude-complex theory may be most useful for predicting treatment outcomes. Snow and colleague Lee Cronbach, developed the Aptitude x Treatment Interaction (ATI) formula, postulating that individual differences in aptitudes may be used to tailor educational instruction in order to optimize learning potential thereby creating the successful “match” (Mayer, as cited in Sternberg, 2000). While preliminary findings of Snow and Cronbach’s Aptitude x Treatment Interaction found mixed results, recent research has yielded more positive findings (Kyllonen & Lajoie, 2003).

As a result of the various types of individual and situational variables that may effect learning and performance, Snow called for aptitudes to be “investigated and understood not simply as a summative test score, but also as a dynamic process” (Kyllonen & Lajoie, 2003). For this reason he believed there was a need for a multivariate approach to validating interpretations of achievement test scores. This call to action was only one of the many legacies that Snow has left behind as his theoretical contributions to the field of educational psychology continue to impact current studies and will likely do so for years to come.


Cronbach, L. J., & Snow, R. E. (1977). Aptitudes and instructional methods: A handbook for research on interactions. Oxford, England: Irvington.

Snow, R. E. (1992). Aptitude theory: Yesterday, today, and tomorrow. Educational Psychologist, 27, 5-32.

Snow, R. E. (1994). Abilities in academic tasks. In R. J. Sternberg & R. K. Wagner (Eds.), Mind in context: Interactionist perspectives on human intelligence (pp. 3-37). Cambridge: Cambridge University Press.

Snow, R. E., Corno, L., & Jackson, D. N., III. (1996). Individual differences in affective and conative functions. In D. C. Berliner & R. C. Calfee (Eds.), Handbook of educational psychology (pp. 243-308). New York: Simon & Schuster.

Nussbaum, E. M., Hamilton, L. S., & Snow, R. E. (1997). Enhancing the validity and usefulness of large-scale educational assessments. IV. NELS:88 science achievement to 12th grade. American Educational Research Journal, 34, 151-173.


Cronbach, L. J., Shavelson, R. J., & Shulman, L. S. (1998). Memorial Resolution for Richard Snow.

Kyllonen, P. C. & Lajoie, S. P. (2003). Reassessing aptitude: Introduction to a special issue in honor of Richard E. Snow. Educational Psychologist, 38(2), 79-83.

Mayer, R. E. (2000). Intelligence, society, and culture. In R. J. Sternberg, Handbook of intelligence (pp. 518-533). Cambridge: Cambridge University Press.

Sattler, J. (2001). Assessment of children: Cognitive applications (4th Edition). San Diego: Jerome M. Sattler, Publisher, Inc.

Shavelson, R. J., Kupermintz, H., Ayala, C., Roeser, R. W., Lau, S., Haydel, A., Schultz, S., Gallagher, L. & Quihuis, G. (2002). Richard E. Snow’s remaking of the concept of aptitude and multidimensional test validity: Introduction to the special issue. Educational Assessment, 8(2), 77-99.