Who was the first individual to measure intelligence in relation to the normal curve?

The question pertains to the history of intelligence testing and the development of measurement theories. Alfred Binet is significant in this context because he was the first to create a systematic method for assessing intelligence through the Binet-Simon Scale. This scale introduced the concept of mental age and placed individuals on a continuum of intelligence.

While Binet's work was foundational, it was Lewis Terman who later adapted Binet's ideas and created the Stanford-Binet Intelligence Scale. Terman's contributions included standardizing the test and introducing the concept of the intelligence quotient (IQ), which allowed for the distribution of intelligence scores along a normal curve. This statistical representation of intelligence allowed for a more nuanced understanding of individual performance relative to the general population.

Binet's initial efforts laid the groundwork for these developments, but it was Terman who specifically measured intelligence in relation to the normal curve. His work made it possible to interpret intelligence scores not just as isolated measures, but as comparisons against a norm, which is essential in psychometrics.