The Mismeasure of Man is a book by Harvard evolutionary biologist, paleontologist, and historian of science Stephen Jay Gould, published in 1981. It is both a history and critique of the statistical methods and cultural motivations underlying biological determinism, the belief that "the social and economic differences between human groups—primarily races, classes, and sexes—arise from inherited, inborn distinctions and that society, in this sense, is an accurate reflection of biology." The principal theme of biological determinism—that "worth can be assigned to individuals and groups by measuring intelligence as a single quantity"—is analyzed in discussions of craniometry and psychological testing, the two methods used to measure and establish intelligence as a single quantity. According to Gould, the methods harbor "two deep fallacies." The first is the fallacy of "reification", which is "our tendency to convert abstract concepts into entities" such as the intelligence quotient (IQ) and the general intelligence factor (g factor), which have been the cornerstones of much research into human intelligence. The second fallacy is "ranking", which is the "propensity for ordering complex variation as a gradual ascending scale."
The revised and expanded, second edition of the Mismeasure of Man (1996) analyzes and challenges the methodological accuracy of The Bell Curve (1994), by Richard Herrnstein and Charles Murray, which re-presented the arguments of what Gould terms biological determinism, which he defines as "the abstraction of intelligence as a single entity, its location within the brain, its quantification as one number for each individual, and the use of these numbers to rank people in a single series of worthiness, invariably to find that oppressed and disadvantaged groups—races, classes, or sexes—are innately inferior and deserve their status."