Palo Alto: A History of California, Capitalism, and the World Highlight

Some had more to work with than others, and that diversity of inherent and immutable ability was important and, they believed, understudied. Without a way to test for superior ability, identifying it in students was haphazard and unscientific, and so was public education in general. If intellectual capacity were a single genetic trait—and they believed it was—then it should be testable. Terman set about making it so, adapting a French intelligence test used to identify students who were falling behind. Against the explicit warning of the test’s author, Alfred Binet, Terman and his Stanford team reformatted it into a measure of inborn general intelligence, expressed in a single number, the ratio of “mental age” to actual age multiplied by 100.10 From there Terman and company were off to the races, marketing “Stanford-Binet” tests, estimating the IQs of famous dead people, and looking for geniuses.