Who invented the first practical IQ test, the Binet-Simon test?

• A. David Wechsler
• B. Lewis Terman
• C. Alfred Adler
• D. Alfred Binet

Answer: (D)

The main idea here is understanding how standardized testing for intellectual abilities began. Alfred Binet, collaborating with Théodore Simon, created the first practical instrument in the early 20th century to help identify which children might need extra educational support. Their test was grounded in tasks that progressed with age, so a child’s performance could be translated into a mental age—a way to compare a child’s cognitive abilities to the typical abilities of peers at different ages. This approach gave schools a practical, objective method to assess learning needs, rather than relying on vague impressions. Although later adaptations, like the Stanford-Binet, broadened and formalized IQ scoring in the United States, the inventor credited for this foundational, practical intelligence test is Alfred Binet.