Can You Increase Your IQ?

It's one of psychology's oldest 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. As an adult you probably can't move your rank much, but you can move your everyday performance, and several things that suppress it are under your control.

First, two different things called "intelligence"

The confusion starts because "IQ" bundles two broad abilities that respond very differently to effort:

• Fluid intelligence (Gf) — reasoning about new problems in the moment. Hard to shift durably in adults.
• Crystallized intelligence (Gc) — the knowledge and skill you accumulate. It keeps growing for decades and responds directly to learning.

When people ask "can I raise my IQ," they usually picture moving Gf. But most of the usable gains in everyday thinking come from Gc, and from removing the things that pull your existing ability down.

The case for a stable rank

The traditional view has real evidence behind it. Twin and adoption studies put the heritability of IQ at roughly 50–80% in adulthood (Plomin & Deary, 2015). That is a statement about differences within a population, not a fixed share of any one person's score, but it fits the second finding: people's rank among their peers is strikingly stable over decades (Deary et al., 2000). Childhood environment clearly matters. By adulthood, though, nobody has a reliable method for turning a 100 into a 140.

The case for change

And yet scores do move. The interventions with the best support:

• Education itself. The strongest evidence comes from schooling. A meta-analysis of quasi-experimental studies estimated that each additional year of education raises IQ by roughly 1 to 5 points (Ritchie & Tucker-Drob, 2018). That is measured in school years, not weekends.
• Complex, sustained learning. Learning a language, an instrument or a demanding skill keeps you engaged and builds real knowledge. Evidence that it improves reasoning in general is mixed: meta-analyses find little or no advantage in executive functions for bilingual adults (Lehtonen et al., 2018) and little far transfer from music or chess training (Sala & Gobet, 2017). Do it for the skill, not for an IQ bump.
• Physical activity. Exercise programs improve cognitive function in adults over 50 in pooled trials (Northey et al., 2018). Evidence that exercise raises IQ in healthy young adults is much weaker.
• Sleep and health. Not glamorous. Short sleep mainly hurts attention and speed (Lim & Dinges, 2010), and illness, stress and fatigue pull performance below your usual level. Removing those does not raise your ceiling, but it stops you scoring under it.

What doesn't work: the brain-game problem

App stores are 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. The gains rarely spread to general reasoning or to anything you do off-screen. A large independent review found extensive evidence that training improves the trained tasks, less for closely related tasks, and little for distantly related tasks or everyday performance (Simons et al., 2016). Working memory training in particular shows no convincing gain on intelligence measures once studies use active control groups (Melby-Lervåg et al., 2016). Treat "this app raises your IQ" as a marketing claim, not a research finding.

The Flynn effect: populations changed

There is one more clue that environment matters. Through much of the 20th century, average raw performance on IQ tests rose in many countries, by roughly 3 points per decade in James Flynn's widely cited estimates (Flynn, 1987). A meta-analysis covering 1909 to 2013 confirmed large gains worldwide, slowing in recent decades (Pietschnig & Voracek, 2015), and some countries have since seen declines. That is far too fast to be genetic, so it shows that conditions matter, but it works over generations, not training sessions.

The realistic conclusion

Put it together and the picture is freeing rather than fatalistic. Your rank relative to peers is unlikely to swing wildly in adulthood. But schooling demonstrably raises scores, knowledge keeps accumulating for decades, and sleep, health and freedom from distraction decide how close to your usual level you perform on any given day. For the long-term studies, including adoption and schooling designs, see what the long-term studies show about IQ change on our sister site, My IQ Path.

Get a current reading

My Path's IQ test has a 12-item short form and a 60-item full form, both free, covering six areas: fluid, verbal, numerical and spatial reasoning, working memory and processing speed. The result shows your percentile among people who took the same form, its range, and that position re-expressed as an estimated IQ (≈ N, with a range). It is an estimate, not a clinical IQ.

A retake shows a rough position again; small changes are within the margin of error, and a second attempt usually scores a little higher simply because the formats are familiar (Hausknecht et al., 2007). It cannot tell you whether a new habit is paying off.

Take the free IQ test →

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.