The Mismeasure Of Man

In Chapter 5, Gould introduces the work of Alfred Binet (1857-1911), the inventor of the intelligence scale used to measure a person’s intelligent quotient (IQ). Binet began his career as a craniometric scientist measuring the heads of school children. After three years of study, he not only concluded that differences in size were “too small to matter,” he became wary of the possibility of unconscious bias in his own research (177).

When Binet returned to intelligence measurement in 1904, he focused his efforts on developing psychological tasks to explore the “various aspects of reasoning more directly” (179). By 1911, he had published three versions of his leveled tasks, which aimed at identifying a child’s intellectual level based on the series of tasks they were able to successfully reach and complete. This number was intended to be a rough guide for identifying learning-disabled children, not a label of “inborn intelligence” or a “device for ranking all pupils according to mental worth,” which Binet did not see as a “fixed and inborn quality” (182, 184). Binet presented these three principles to avoid the misuse of IQ.

Gould then introduces three forerunners of hereditarianism in America: