Lewis Madison Terman (January 15, 1877 – December 21, 1956) was an American psychologist, academic, and proponent of eugenics.

A Review of General Psychology survey, published in 2002, ranked Terman as the 72nd most cited psychologist of the 20th century, in a tie with G. Stanley Hall.

His son, Frederick Terman, is widely credited (together with William Shockley) with being the father of Silicon Valley.

Early on, Terman adopted William Stern's suggestion that mental age/chronological age times 100 be made the intelligence quotient or IQ.

Terman followed J. McKeen Cattell's work which combined the ideas of Wilhelm Wundt and Francis Galton saying that those who are intellectually superior will have better "sensory acuity, strength of grip, sensitivity to pain, and memory for dictated consonants".

[11] His fascination with the intelligence of children began early in his career since he was familiar with Alfred Binet's research in this area.

[13] Previously, the research looking at genius adults had been retrospective, examining their early years for clues to the development of talent.

With Binet's development of IQ tests, it became possible to quickly identify gifted children and study them from their early childhood into adulthood.

Terman wrote that "[bright children] are rarely given tasks which call forth their best ability, and as a result they run the risk of falling into lifelong habits of submaximum efficiency".

[12] In other words, nature (heredity) plays a large role in determining intelligence, but nurture (the environment) is also important in fostering the innate intellectual ability.

They cannot master abstractions but they can often be made into efficient workers... from a eugenic point of view they constitute a grave problem because of their unusually prolific breeding[26]Terman's work in addition to other openly eugenic psychologists and education scholars such as Edward Thorndike, Leta Hollingworth, Carl Brigham, and H. H. Goddard contributed to long standing policies and practices of racial school segregation.

In this same book, Terman further stated that eugenics was important in the study of intelligence because "considering the tremendous cost of vice and crime…it is evident that psychological testing has found here one of its richest applications".

[27] He further insisted that human "dullness... seems to be racial, or at least inherent in the family" and found with "extraordinary frequency among Indians, Mexicans, and negroes".

[29]The suggestions of a significant role for genetics in IQ led Terman to later join the Human Betterment Foundation, a Pasadena-based eugenics group founded by E. S. Gosney in 1928 which had as part of its agenda the promotion and enforcement of compulsory sterilization laws in California.

Stern et al. (2017) documented significant long-standing violence inflicted on those identified by eugenicists as unfit and sterilized.

He naively assumed that his high IQ kids (nearly all white) would become the future leaders of science, industry, and politics.