Binet Simon IQ tests

The Binet Simon IQ tests were amongst the first systematic attempts to measure intelligence

Alfred Binet and physician Theodore Simon collaborated in studying mental retardation in French school children. Between 1905 and 1908, their research at a boys school, in Grange-aux-Belles, led to their developing the Binet-Simon tests; via increasingly difficult questions, the tests measured attention, memory, and verbal ability. Binet warned that such test scores should not be interpreted literally, because intelligence is plastic and the margin of error inherent to the test (Fancher, 1985).

In 1916, the Stanford psychologist Lewis Terman released the "Stanford Revision of the Binet-Simon Scale", the "Stanford-Binet", for short. Helped by graduate students and validation experiments, he removed some Binet-Simon test items and added new ones. Soon, the test was so popular that Robert Yerkes, the president of the American Psychological Association, decided to use it in developing the Army Alpha and the Army Beta tests to classify recruits. Thus, a high-scoring recruit might earn an A-grade (high officer material), whereas a low-scoring recruit with an E-grade would be rejected for military service. (Fancher, 1985).