crystallized intelligence

Meaning: Crystallized intelligence is the knowledge and skill a person has accumulated through education and experience, such as vocabulary, general facts and learned procedures. In the Cattell–Horn model it is paired with fluid intelligence. Because it rests on information stored in long-term memory, it reflects schooling and culture and can keep growing as long as a person keeps learning.

On the MCAT: Passages often compare age groups on two kinds of tasks. Vocabulary, general-knowledge and reading tests measure crystallized intelligence, and older adults typically score as well as or better than younger adults on them. Novel puzzles, pattern completion and speed-dependent tasks measure fluid intelligence, which tends to decline in later adulthood. You may be asked to classify an example or predict the age trend on a graph.

Common confusion: Students swap the two. Crystallized intelligence is the one that tends to be maintained with age; fluid intelligence is reasoning on new problems without relying on prior learning. A highly educated person solving a brand-new logic puzzle is using fluid intelligence, not crystallized.