Theories

Although Binet intended his intelligence test to be a practical tool, it became impossible to separate this tool from the theoretical questions it raised: What was intelligence? How can it be tested? And how should researchers use the test results? These questions remain at the heart of a lively debate over intelligence testing.

Main points

Binet's ideas about intelligence were rooted in his earlier theory of individual psychology. He continued to stress variation, both within and across individuals. Based on his previous work, Binet was also convinced that such individual differences could best be detected by studying complex mental processes, such as memory, attention, imagination, and comprehension.

What is intelligence? Binet was always more concerned with measuring intelligence than with...