Can You Increase Your IQ?
It's one of psychology's most durable arguments dressed up as a self-help question: is intelligence something you can build, or a ceiling you were handed at birth? The honest answer is uncomfortable for both camps. You probably can't move your rank much as an adult — but you can move your performance a great deal, and most people never come close to the limit of what their cognition can do.
First, two different things called "intelligence"
The confusion starts because "IQ" bundles two systems that respond very differently to effort:
- Fluid intelligence (Gf) — raw, in-the-moment reasoning on novel problems. Biologically driven, harder to shift.
- Crystallized intelligence (Gc) — the knowledge and skill you accumulate. It grows for decades, almost entirely under your control.
When people ask "can I raise my IQ," they usually picture moving Gf. But most of the usable gains in everyday cognitive output come from Gc — and from removing the things that suppress your existing ability.
The case for a fixed ceiling
The traditional view has real evidence behind it. Twin and adoption studies put the heritability of IQ at roughly 50–80% in adulthood, and your relative rank tends to be strikingly stable across decades. Childhood environment — nutrition, schooling, stimulation — clearly matters, but by adulthood your raw cognitive capacity is, to a large degree, set. Nobody reliably engineers a jump from 100 to 140.
The case for plasticity
And yet the brain is not concrete. It reorganizes in response to demand — it builds and prunes connections throughout life. That doesn't license fantasy, but it does mean cognitive performance is movable. The interventions with the best support:
- Complex, sustained learning. Acquiring a language or an instrument forces new neural pathways and strengthens executive function — broad, transferable work, unlike memorizing trivia.
- Aerobic exercise. Physical activity raises BDNF, a protein that supports the growth and survival of neurons, with measurable cognitive benefits.
- Education itself. One of the most replicated findings in the field: each additional year of schooling is associated with a small but real bump in measured IQ.
- Sleep and nutrition. Not glamorous. A rested, well-fed brain simply performs closer to its actual capacity; a depleted one underperforms its own ceiling every day.
What doesn't work: the brain-game problem
The app store is full of products promising a higher IQ. The evidence is consistently disappointing, and the reason has a name: the transfer problem. Practice a specific task and you get better at that task — your scores climb impressively. But the gains rarely transfer to general reasoning or to anything you do off-screen. You become an expert at the game, not a more capable thinker. Treat "this app raises your IQ" as a marketing claim, not a research finding.
The Flynn effect: we got smarter together
There's one more clue that environment matters. Across the 20th century, average raw IQ performance rose about three points per decade — the Flynn effect. Better nutrition, more schooling, and the rising abstraction of daily life appear to have lifted entire populations. It's a powerful demonstration that cognitive performance responds to conditions — even if the cause operates at the level of generations, not gym sessions.
The realistic conclusion
Put it together and the picture is freeing rather than fatalistic. You likely have a biological ceiling on fluid ability, and your rank relative to peers won't swing wildly. But almost nobody lives at their ceiling. Through genuine learning, physical health, adequate sleep, and steady mental challenge, you can raise what your brain actually delivers — and that, not a number on a chart, is what shows up in your work and your life.
Get a current reading
The most useful baseline is a recent, honest one. My Path's IQ assessment returns an estimated range with a confidence interval and a subtest profile, so you can see where you stand now — and, if you retake it later, whether your habits are paying off.
Since motivation and consistency do more of the heavy lifting than most people expect, it's worth pairing this with the Big Five to see how your conscientiousness and openness support (or undercut) the habits above.