Who was one of the first psychologists to work on intelligence?

The correct answer is Option (1) → Alfred Binet

Option (1) Alfred Binet — Correct. Binet was one of the first psychologists who worked on intelligence. He defined it as the ability to judge well, understand well and reason well, and with Simon he built the first intelligence test.

Option (2) David Wechsler — Incorrect. Wechsler came later. His tests are the most widely used, and he saw intelligence as the global and aggregate capacity to think rationally, act purposefully and deal effectively with the environment.

Option (3) Francis Galton — Incorrect. Galton studied individual differences and heredity, but he did not build a test of intelligence as such; the first intelligence test was Binet’s.

Option (4) William Stern — Incorrect. Stern built on Binet’s work: he devised the intelligence quotient (IQ), mental age divided by chronological age, multiplied by 100.