Measuring Intelligence.

The measurement of intelligence forced its way into Americans' public consciousness during World War I, when some 1.7 million U.S. recruits were tested by the army under the direction of Col. Robert M. Yerkes. The findings provided the first large-scale evidence from the "science of mental testing" that American-born blacks and some of the foreign-born draftees scored lower on intelligence tests than did American- born whites. After the war the army's system of scoring was translated into mental age levels, and the results were made public. According to the scales and the method of calculation then in use, it was estimated that the average army draftee had a mental age of about fourteen years. These tests initiated a debate that has gone on ever since. What is intelligence? Can it be measured?

The Army Alpha Tests.

The army had...