While many people claim that their intelligence seems to decline as they age, research suggests that while fluid intelligence begins to decrease after adolescence, crystallized intelligence continues to increase throughout adulthood.
What are fluid and crystallized intelligence? Psychologist Raymond Cattell first proposed the concepts of fluid and crystallized intelligence and further developed the theory with John Horn. The Cattell-Horn theory of fluid and crystallized intelligence suggests that intelligence is composed of a number of different abilities that interact and work together to produce overall individual intelligence.
What is Fluid Intelligence?
Cattell defined fluid intelligence as "…the ability to perceive relationships independent of previous specific practice or instruction concerning those relationships."
Fluid intelligence involves being able to think and reason abstractly and solve problems. This ability is considered independent of learning, experience, and education. Examples of the use of fluid intelligence include solving puzzles and coming up with problem-solving strategies.
What Is Crystallized Intelligence?
Crystallized intelligence involves knowledge that comes from prior learning and past experiences. Situations that require crystallized intelligence include reading comprehension and vocabulary exams. This type of intelligence is based upon facts and rooted in experiences. As we age and accumulate new knowledge and understanding, crystallized intelligence becomes stronger.
Fluid vs. Crystallized Intelligence
According to Knox (1977), ". . . they constitute the global capacity to learn, reason and solve problems that most people refer to as intelligence. Fluid and crystallized intelligence are complementary in that some learning tasks can be mastered mainly by exercising either fluid or crystallized intelligence."
Both types of intelligence are equally important in everyday life. For example, when taking a psychology exam, you might need to rely of fluid intelligence to come up with a strategy to solve a statistics problem, while you must also employ crystallized intelligence to recall the exact formulas you need to use.
Fluid and Crystallized Intelligence Throughout Life
- Both types of intelligence increase throughout childhood and adolescence.
- Fluid intelligence peaks in adolescence and begins to decline progressively beginning around age 30 or 40.
- Crystallized intelligence continues to grow throughout adulthood.
Horn, J. L., & Cattell, R. B. (1967). Age differences in fluid and crystallized intelligence. Acta Psychologica, 26, 107-129.
Knox, A. B. (1977). Adult development and learning. San Francisco: Jossey-Bass.