— Cognitive concept
Fluid Intelligence
The ability to reason abstractly and solve novel problems, independent of acquired knowledge.
Fluid intelligence (Gf) is one of the two major components of human general intelligence, proposed by psychologist Raymond Cattell in the 1940s. It refers to the capacity to reason, recognise patterns, and solve problems in situations you've never encountered before — without relying on prior knowledge or learned skills.
How it differs from crystallised intelligence
Fluid intelligence pairs with crystallised intelligence (Gc) — the knowledge, vocabulary, and skills you accumulate over time. The classic distinction:
- Fluid (Gf): raw reasoning power. Solving a brand-new puzzle. Peaks in early adulthood (~age 20-25) and gradually declines.
- Crystallised (Gc): knowledge and verbal skill. Recalling facts, applying learned procedures. Continues rising into your 60s.
How fluid intelligence is measured
Tests of fluid intelligence specifically use novel material that can't be solved by drawing on prior knowledge. The most famous example is Raven's Progressive Matrices — pattern-completion tasks with abstract visual symbols. Modern IRT-based tests like Core Brain test fluid intelligence across multiple axes: pattern, spatial, logic, numeric, and matrix reasoning.
Can you increase your fluid intelligence?
This is heavily contested. Some training studies show short-term gains on the specific trained task, but transfer to broader reasoning tasks is weak. The strongest evidence is that adequate sleep, regular cardiovascular exercise, and avoiding chronic stress preserve fluid intelligence in adulthood — but raising it substantially is much harder than maintenance.
Related concepts
- Crystallised Intelligence
- The g-factor (general intelligence)
- The Flynn Effect
- Verbal IQ
- Performance IQ