— Cognitive concept
Crystallised Intelligence
The accumulated knowledge, vocabulary, and skills you've acquired over your lifetime.
Crystallised intelligence (Gc) is the second major component of human general intelligence in the Cattell-Horn-Carroll (CHC) theory. Where fluid intelligence is raw novel-problem reasoning, crystallised intelligence is the accumulated knowledge you draw on — vocabulary, general knowledge, learned procedures, and applied expertise.
How it grows over a lifetime
→Pause. Find out YOUR IQ before you keep reading.Unlike fluid intelligence, which peaks in early adulthood and gradually declines, crystallised intelligence continues to grow throughout adult life, typically peaking in the 60s or 70s before slow decline. This is why older adults often outperform younger ones on vocabulary, general knowledge, and judgement tasks despite slower processing speed.
How it's measured
→Curious how YOU score? 20-min calibrated test.Vocabulary subtests, general information tests, and reading comprehension are the classic Gc measures. The verbal portion of the WAIS-IV (verbal comprehension index) is largely a Gc measure.
Why this matters for IQ testing
→The numbers above? Find out where YOU land.Most modern IQ tests deliberately balance fluid and crystallised components. Pure fluid tests (like Raven's) may underestimate older adults; pure crystallised tests favour the well-educated. A composite IQ score blends both for a more representative picture.