How Lewis Terman Influenced the Field of Psychology

Lewis Terman was an influential psychologist who is known for his version of the Stanford-Binet intelligence test and for his longitudinal study of giftedness. His research is the longest-lasting longitudinal study ever conducted. His work added important contributions to the understanding of how intelligence influences life success, health, and outcomes.

Lewis Terman's Influence on Psychology

Terman is best known for:

  • Genetic studies of genius
  • Educational psychology pioneer
  • Eugenics
  • Further development and refinement of the Binet-Simon IQ test
  • Mental testing

Early Life

Lewis Madison Terman was the 12th of 14 children born on January 15, 1877 to a farming family in Indiana. While few of his peers studied past the 8th-grade, Terman was both bookish and ambitious. His early experiences were perhaps what fueled his later passion for studying intelligence and giftedness.

Aided by loans from his family, Terman completed his BS, BP and BA degrees at Central Normal College from 1892 and 1898. He then went on to earn a BA and MA from Indiana University at Bloomington in 1903. In 1905, he earned his Ph.D. in Psychology from Clark University.

Career and Research

Terman's Ph.D. thesis centered on mental tests that could be used to distinguish gifted students from those that were cognitively impaired. He developed tests that measured complex cognitive abilities and included measures of creativity, mathematical ability, memory, motor skills, logic, and language mastery.

After graduating, he initially worked as a school principal in California and two years later became a professor at Los Angeles State Normal School. In 1910, he became a professor at Stanford University, where he would remain until his death in 1956.

After becoming a professor at Stanford, he worked on revising the original Binet-Simon scales for use with American populations. His updated version of the test became known as the Stanford-Binet and went on to become the most widely used IQ test. In addition to revising the original test, he also began using a formula that involved taking mental age, dividing it by chronological age, and multiplying it by 100 to come up with what is known as the intelligence quotient or IQ.

The first wide-scale use of Terman's test occurred during the First World War, where the test was adapted and combined with other assessments to form the Army alpha (text-based) and Alpha-beta (picture-based) tests. Millions of soldiers were given these assessments, and those who received an "A" or "B" score were promoted to officer training while those who received a "D" or "E" were not given such training.

Terman was also a noted eugenicist, once citing Galton as a prime influence. At one point, he administered English tests to native Spanish-speakers as well as unschooled Black students and concluded that the ensuing low scores were the result of inheritance and had a racial basis. Terman was also a member of the Human Betterment Foundation, a group that advocated, among other things, forced sterilization of those who were deemed mentally unfit.

Terman's Genius Study

In 1921, Terman began his "Genetic Studies of Genius," a longitudinal study that set out to investigate whether high IQ students were more successful in life. What he found was that his high IQ subjects (which he referred to as "Termites") tended to be healthier, taller, and more socially adapted than other kids.

Based on his results, Terman suggested that gifted children should be identified early, offered tailored instruction, and have access to specially-trained teachers. Terman found that while many of his high IQ subjects were very successful, not all fared as well and most actually turned out no better than the average. He did find that those who ended up being the most successful tended to rate higher on self-confidence, perseverance, and goal-orientation as children.

The study is still going on today, carried out by other psychologists, and has become the longest-running study in history.

Select Publications

Terman published a number of books and articles that detailed the research he conducted looking at intelligence and IQ testing. Some of these include:

Terman, L. M. (1916). The Measurement of Intelligence: An Explanation of and a Complete Guide for the use of the Stanford Revision and Extension of the Binet-Simon Intelligence Scale. Boston. Houghton Mifflin Co.

Terman, L. M. (1917). The Stanford Revision and Extension of the Binet-Simon Scale for Measuring Intelligence. Baltimore. Warwick & York, Inc.

Terman, L. M. (1925). Genetic Studies of Genius. Stanford: Stanford University Press.

Terman, L. M. (1930). Autobiography of Lewis Terman. In Carl A. Murchison, and Edwin G. Boring. A History of Psychology in Autobiography. Worcester, MA: Clark University Press.

Terman, L. M., and Merrill, M. A. (1937). Measuring Intelligence: A Guide to the Administration of the new Revised Stanford-Binet tests of Intelligence. Boston: Houghton Mifflin company.

Terman, L. M., Oden. M. H., and Bayley, N. (1947). The Gifted Child Grows Up: Twenty-five Years' Follow-up of a Superior Group. Genetic studies of genius. v. 4. Stanford: Stanford University Press.

Contributions to Psychology

Lewis Terman played an important role in the early development of educational psychology and his intelligence test became one of the most widely used psychological assessments in the world. He advocated for support and guidance for kids identified as gifted in order to nurture their talents and abilities.

Yet Terman's legacy is tainted by one of the motivations underlying much of his early research - a belief in selectively eliminating certain "undesirable" traits through the use of eugenics and compulsory sterilizations of so-called "feebleminded" individuals. While he later backed down from this staunch position in his later life, he never formally renounced the beliefs he had advocated for so long.

Wrestling with Terman's difficult legacy involves weighing his many contributions to the field and the influence his IQ test had on the world against the cold-hearted attitudes that motivated so much of his work.

 "One one hand, his work inspired almost all the innovations we use today to challenge bright kids and enrich their education," wrote Mitchell Leslie for Stanford Magazine. "On the other hand, as biographer Minton points out, the very qualities that made Terman a groundbreaking scientist - his zeal, his confidence - also made him dogmatic, unwilling to accept criticism or to scrutinize his hereditarian views."

In one study ranking the most influential psychologists of the 20th century, Terman was tied with G. Stanley Hall at number 72.

Terman died on December 21, 1956.

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  • Robinson, A, & Jolly, J. A Century of Contributions to Gifted Education: Illuminating Lives. New York: Routledge; 2013.

  • Sheehy, N, Chapman, AJ, & Conroy, WA. (Eds). Lewis Terman. In Biographical Dictionary of Psychology. New York: Routledge; 2016.

By Kendra Cherry, MSEd
Kendra Cherry, MS, is a psychosocial rehabilitation specialist, psychology educator, and author of the "Everything Psychology Book."