The psychologist Raymond B. Cattell formulated the “hypothesis of fluid and crystallized abilities” in the 1940s, when standardized intelligence tests started being used frequently for selection and management purposes. While fluid intelligence reflects basic cognitive abilities, such as reasoning, which are independent of learning and experience, crystallized intelligence reflects the abilities to use cultural, educational, and vocational knowledge and experience to learn, partially by relying on one's fluid abilities, and subsequently solve problems. Two distinctive features of this account of intelligence are its explicit developmental predictions and its reliance on factor‐analytic techniques for empirical testing of its structure. Evidence stemming from neuropsychology and neurology also partially supports the distinction between fluid and crystallized abilities. Several tasks have been proposed to assess an individuals' crystallized intelligence (e.g., language development, lexical knowledge, general information). However, those most frequently used rely highly on verbal surface knowledge, rather than reflecting broader knowledge.