One of the first theorists to discuss factors.

• A. Spearman
• B. Guilford
• C. Thurstone
• D. Vernon

Answer: (A)

The main idea here is recognizing who first introduced the use of factors to explain intelligence and to analyze cognitive abilities. Spearman is the earliest figure to do this in a formal way: he developed factor analysis as a method and proposed a general intelligence factor, g, which accounts for correlations among diverse cognitive tasks. This set the foundation for thinking about underlying factors that drive performance on different tests, a concept later researchers expanded but did not originate. While Guilford and Thurstone later argued for multiple factors or a more complex structure of intellect, and Vernon built hierarchical models, the notion of using factors to explain shared variance began with Spearman. That historical role is why he is the best choice here.