fluid intelligence

A potential answer lies in the work of the British psychologist Raymond Cattell, who in the early 1940s introduced the concepts of fluid and crystallized intelligence. Cattell defined fluid intelligence as the ability to reason, analyze, and solve novel problems—what we commonly think of as raw intellectual horsepower. Innovators typically have an abundance of fluid intelligence. It is highest relatively early in adulthood and diminishes starting in one’s 30s and 40s. This is why tech entrepreneurs, for instance, do so well so early, and why older people have a much harder time innovating.Crystallized intelligence, in contrast, is the ability to use knowledge gained in the past. Think of it as possessing a vast library and understanding how to use it. It is the essence of wisdom. Because crystallized intelligence relies on an accumulating stock of knowledge, it tends to increase through one’s 40s, and does not diminish until very late in life.Careers that rely primarily on fluid intelligence tend to peak early, while those that use more crystallized intelligence peak later. For example, Dean Keith Simonton has found that poets—highly fluid in their creativity—tend to have produced half their lifetime creative output by age 40 or so. Historians—who rely on a crystallized stock of knowledge—don’t reach this milestone until about 60.

Your Professional Decline Is Coming (Much) Sooner Than You Think Arthur C. Brooks 2022