Can You Raise Your IQ? What the Research Actually Shows
The short answer: a little — yes, a lot — no. Genetics accounts for roughly 50–80% of IQ variation in adults. The rest comes down to environment: education, nutrition, sleep, and stress. Removing the factors that drag your intelligence down is genuinely possible. Pushing your IQ above your natural ceiling, however, has eluded everyone so far — despite billions of dollars poured into "brain training."
What IQ Actually Measures
IQ isn't a measure of how much you know. These tests measure the speed and accuracy of information processing: logic, working memory, spatial reasoning, and vocabulary. The standard scale is designed so that the average score is 100 and the standard deviation is 15. About 68% of people score between 85 and 115.
One important thing to understand: IQ is a relative measure. It compares you to a sample of people your own age. So "raising your IQ" doesn't just mean getting smarter — it means getting smarter faster than everyone else.
What Drags IQ Down — and What You Can Fix
Before thinking about gains, it's worth eliminating the factors that artificially suppress your score. Their impact is far greater than any training program.
- Sleep deprivation. A single night of five hours' sleep impairs cognitive test performance to a degree comparable to mild intoxication. Chronic sleep loss builds up a deficit that people stop noticing subjectively — but tests still pick it up.
- Iron and B12 deficiency. Both are essential for neuronal myelination. In children, iron deficiency is consistently linked to lower IQ. In adults, correcting the deficiency restores scores to baseline — but doesn't push them above it.
- Chronic stress. High levels of cortisol damage the hippocampus and impair working memory. This is reversible once the source of stress is removed.
- Air pollution. Fine particulate matter (PM2.5) is associated with cognitive decline, particularly in children and older adults.
- Poverty and chaotic early environments. This is one of the most powerful factors of all. Children from disadvantaged backgrounds who were adopted into high-socioeconomic-status families scored 12–18 IQ points higher than siblings who remained in their original environment. This data comes from French adoption studies conducted in the 1970s and 80s.
Education: The Most Reliable Effect
Each additional year of formal schooling adds roughly 1–5 IQ points — one of the most reproducible findings in psychometrics. This applies to structured education, not self-study through YouTube.
The mechanism appears to be twofold: school trains the very skills that IQ tests measure (abstract reasoning, working with symbols), and it also builds the habit of sustained mental effort.
A 2018 study in Nature Human Behaviour analyzed data from more than 600,000 people and confirmed that education has a causal effect on IQ — not merely a correlational one.
Brain Training: Marketing vs. Science
The brain training industry makes billions on promises to raise IQ. The reality is far more modest.
Working memory training is the most thoroughly studied approach. Early experiments in the 2000s produced optimistic results: people improved their fluid intelligence test scores after completing n-back training (a task requiring you to remember sequences). But subsequent meta-analyses found that the gains barely transfer to tasks different from the ones being practiced. You get better at n-back — not at intelligence itself.
In 2014, more than 70 leading cognitive psychologists and neuroscientists signed an open letter warning about the misleading advertising used by brain training companies. Their position: there is no convincing evidence that these programs improve everyday thinking or slow its age-related decline.
Exercise: A Modest but Real Effect
Aerobic exercise — running, swimming, cycling — increases production of BDNF, a neurotrophic factor that supports the growth and survival of neurons, particularly in the hippocampus.
Meta-analyses consistently find small but statistically significant improvements in executive function and memory among people who exercise regularly. The effect is most pronounced in older adults and children.
How much this actually moves the IQ needle is hard to say. Results range from zero to a few points depending on study design. But physical activity clearly does no harm, and the long-term data on preserving cognitive function is fairly compelling.
Diet and Supplements
A balanced diet with adequate protein, omega-3 fatty acids, zinc, and iron is the necessary foundation. Correcting deficiencies brings cognitive function back to baseline — but doesn't push it above baseline in people who aren't deficient to begin with.
As for popular supplements:
- Omega-3 (fish oil): beneficial when there's a deficiency; in healthy adults without one, the effect on IQ is unproven.
- Creatine: some evidence of modest working memory improvement in people on vegetarian diets, where baseline brain creatine levels are lower.
- "Nootropics" and "smart pills": most over-the-counter supplements marketed this way have not been rigorously tested in healthy individuals.
Age and IQ: When Does the Ceiling Shift?
Fluid intelligence — processing speed, working memory, abstract pattern recognition — peaks around ages 20–25 and then declines slowly. Crystallized intelligence — accumulated knowledge, vocabulary, experience — keeps growing until the age of 60–70.
This matters for interpreting IQ scores: at 35, you may solve problems faster than you did at 25 thanks to experience, but a standardized IQ test compares you to your peers — so your score stays roughly stable.
| Type of Intelligence | Peak | Trajectory After Peak |
|---|---|---|
| Fluid (speed, logic) | Ages 20–25 | Slow decline |
| Crystallized (knowledge, experience) | Ages 60–70 | Stable into old age |
What Actually Works: A Quick Summary
- Eliminate deficits: sleep, nutrition, stress, physical activity — this isn't "upgrading" yourself, it's getting back to your own baseline.
- Learn through structured education — it produces the most reliable and reproducible effect on IQ.
- Don't expect miracles from apps or supplements that lack a solid evidence base.
- Accept that a genetic ceiling exists — but most people never reach it because of fixable environmental factors.
If you want to understand where you stand right now, you can take the IQMeter test. Your result will show where you fall on the standard scale.
Common Questions
How many IQ points can you realistically gain?
Removing factors that suppress your score — poor sleep, nutritional deficiencies, chronic stress — can restore 5–15 points back to your personal baseline. Each year of education adds roughly 1–5 points. No intervention has yet produced a reproducible effect of pushing IQ above a person's genetically determined ceiling.
Do games and puzzles help?
They improve specific skills: reaction speed, attention to detail, knowledge of the rules involved. Research doesn't support a transfer to general IQ. Crossword puzzles make you better at crosswords — they don't raise your score on a matrices test.
Do children's IQs improve more easily than adults'?
The brain is more plastic during childhood and adolescence, and external factors — education, nutrition, environment — have a stronger influence on IQ than they do in adulthood. That doesn't mean the adult brain doesn't change; it just means the "window of opportunity" for shaping core cognitive structures is wider early in life.
Does bilingualism affect IQ?
Bilingualism is associated with improved executive control — the ability to switch between tasks and suppress irrelevant responses. But research doesn't show a direct increase in IQ scores on standard tests. It's more of a different cognitive profile than a higher overall score.
At what age does IQ stop changing?
After about 16–18, IQ is relatively stable: studies show a correlation of around 0.7–0.8 between childhood and adult IQ scores. That means there is some variability, but large shifts are uncommon. Fluid intelligence declines slowly after 25; crystallized intelligence continues to grow until age 60–70.