How to Increase Your IQ: What the Research Actually Says

Can you increase your IQ? Let us get the uncomfortable truth out of the way first. There is no supplement, app, trick, or 30-day program that will reliably raise your measured IQ by 20 points. Anyone selling that idea is selling you something.

But the more nuanced answer — the one the research actually supports — is genuinely interesting. Cognitive ability is more malleable than most people assume. Specific, evidence-backed interventions can meaningfully improve the cognitive functions that IQ tests measure. Whether that constitutes "raising your IQ" depends on what you mean by the question. To understand why, it helps to first understand what IQ actually measures and how the number is constructed — because the answer to "can you raise it" changes depending on which part of the construct you are targeting.

Here is what we actually know.

First: What Would "Raising IQ" Even Mean?

IQ is a relative measure. It tells you where you stand compared to other people of the same age group. If everyone's cognitive performance improved equally, nobody's IQ score would change — even if everyone got meaningfully smarter in absolute terms. This is a critical point that most discussions of "how to raise your IQ" entirely skip.

So when people ask whether they can increase their IQ, they usually mean one of two things. Either they want to improve their raw cognitive performance — processing speed, working memory, abstract reasoning ability — or they want to score higher on IQ tests specifically. These goals are related but not identical, and the research speaks to them differently.

The evidence is considerably stronger for improving specific cognitive functions than for reliably shifting a properly normed IQ score. Whether improvements in cognitive function translate to a higher test score depends on how much overlap exists between what you trained and what the specific test measures. Understanding how IQ tests are scored and what they are actually measuring across different domains is essential context before evaluating any enhancement claim.

What the Evidence Actually Supports

1. Aerobic Exercise — The Strongest Single Intervention

This is the most robustly supported finding in cognitive enhancement research, and it is not close. Regular aerobic exercise — running, swimming, cycling, brisk walking — produces measurable improvements in executive function, working memory, and processing speed across multiple well-controlled randomised trials in every age group studied.

The mechanism is well understood. Aerobic exercise increases production of BDNF (brain-derived neurotrophic factor), a protein that promotes the growth of new neurons and strengthens synaptic connections, particularly in the hippocampus and prefrontal cortex — the regions most centrally involved in higher reasoning, attention, and cognitive flexibility. It also improves cerebral blood flow and reduces systemic inflammation, both of which have downstream effects on neural efficiency.

The effect sizes are meaningful. A meta-analysis of randomised controlled trials found that regular aerobic exercise improved cognitive performance by approximately 0.5 standard deviations on average — equivalent to roughly 7–8 IQ points if the effect transferred directly to IQ scores, which it partially does. Three to five sessions per week of 30–45 minutes of moderate-to-vigorous cardio is the dosage most consistently associated with cognitive benefits. Resistance training shows some cognitive benefit too, but the effect sizes are smaller and less consistent than for aerobic exercise.

2. Sleep — The Most Underrated Factor

Chronic sleep deprivation is cognitively devastating in ways that are dramatically underappreciated in popular discussions of intelligence. Even mild sleep restriction — consistently getting 6 hours instead of 8 for two weeks — produces cognitive deficits equivalent to two full nights of total sleep deprivation, while the subjects subjectively feel only slightly impaired. The gap between felt impairment and actual impairment is itself a product of sleep deprivation.

The cognitive functions most acutely affected by sleep deprivation are exactly the ones that IQ tests measure: working memory, processing speed, attention control, and novel problem solving. Studies have found that restoring adequate sleep in chronically sleep-deprived populations can improve cognitive test performance by the equivalent of 10 or more IQ points in some cohorts.

For many people, this is the highest-return cognitive intervention available — not some exotic supplement or brain training app, but simply sleeping 7.5 to 9 hours consistently in conditions that allow deep and REM sleep cycles to complete. The research on sleep and cognition is among the most unambiguous in all of neuroscience, yet it is routinely ignored by people spending money on nootropics.

3. Working Memory Training — Partially Effective

Working memory — the ability to hold and manipulate information in short-term memory — is one of the strongest individual correlates of fluid intelligence. This connection made working memory training programs like Dual N-Back extremely exciting to researchers in the 2000s and early 2010s, when early studies suggested that training working memory might transfer to gains in general fluid intelligence.

The findings turned out to be more complicated than the early excitement suggested. Working memory training reliably improves performance on working memory tasks. The evidence for transfer to general fluid intelligence is mixed — some well-controlled studies show modest transfer effects, others find none at all. The current scientific consensus is that working memory training produces specific gains that may partially transfer to similar tasks, but does not produce large general intelligence improvements in most people.

That said, if working memory is a specific weakness for you — which your domain breakdown on a comprehensive IQ assessment can help identify — targeted training in that area has value for its own sake, particularly for academic and professional tasks that are heavily working-memory-dependent.

4. Sustained Intellectual Challenge — Real but Slow

Crystallised intelligence — the accumulated knowledge, vocabulary, and verbal reasoning ability built across a lifetime — genuinely grows with sustained intellectual engagement. Reading widely and deeply, learning new languages, acquiring complex domain expertise, engaging seriously with difficult ideas: all of these build the verbal and reasoning foundations that IQ tests partly measure.

This is a slow process that does not produce dramatic IQ score changes on a weekly timescale. Over years and decades, it is probably the most powerful force shaping cognitive development in adults. The Flynn Effect — the well-documented rise in average IQ across the 20th century — is largely attributed to exactly this kind of environmental enrichment at population scale: more years of formal education, more exposure to abstract problem-solving, and greater familiarity with the kind of reasoning that standardised tests require. The distinction between fluid intelligence (raw reasoning power) and crystallised intelligence (accumulated knowledge and skill) is directly relevant here — intellectual engagement primarily builds the crystallised component, while exercise and sleep support the fluid component.

5. Stress Reduction — Often Overlooked

Chronic psychological stress impairs prefrontal cortex function through cortisol's sustained effects on neural plasticity. The prefrontal cortex governs working memory, inhibitory control, cognitive flexibility, and fluid reasoning — all core components of measured IQ. When cortisol levels are chronically elevated, the prefrontal cortex's ability to support these functions is genuinely compromised at the neurological level, not just behaviourally.

Studies of people in persistently high-stress conditions — poverty, caregiver burden, workplace burnout, ongoing relationship conflict — consistently show reduced performance on cognitive assessments compared to matched controls with lower stress. Critically, when those stressors are removed, cognitive performance recovers substantially. This suggests that for many people, apparent cognitive limitations are actually stress-mediated impairments rather than fundamental capacity constraints.

Evidence-backed stress reduction approaches with demonstrated cognitive benefit include mindfulness-based stress reduction (shown to improve attention and working memory in multiple RCTs), regular aerobic exercise (again), social connection and support, and where possible addressing the sources of chronic stress directly rather than managing only the symptoms.

6. Nutrition — Foundation Matters More Than Supplements

Severe nutritional deficiencies produce measurable cognitive impairment. Correcting them produces measurable cognitive improvement. This is well established for iron deficiency (extremely common globally, strongly linked to reduced IQ in children and to attention and processing deficits in adults), iodine deficiency, and clinically low omega-3 fatty acid status.

In populations without frank nutritional deficiency, the evidence for specific supplements improving IQ in healthy adults is weak to absent. The popular claims about nootropic stacks — racetams, various adaptogenic herbs, lion's mane mushroom, microdosed psychedelics — are largely not supported by rigorous placebo-controlled research at marketed doses and durations. Some show theoretical neurobiological plausibility; very few have demonstrated reliable IQ-relevant performance benefits in methodologically sound human trials.

The baseline nutritional status matters far more than the supplements layered on top of it. A nutrient-sufficient diet, adequate hydration, minimal ultra-processed food, and stable blood glucose creates the neurochemical environment in which optimal cognitive function is achievable. That is a genuine foundation — not a shortcut, but not negligible either.

What Does Not Work

Brain training games like Lumosity and BrainHQ improve your performance at the specific tasks they train. You will become better at the game. The evidence for transfer to general cognitive ability or IQ scores is not convincing, and has been challenged by open letters from over 70 cognitive scientists. The companies behind these products have faced regulatory action specifically for overstating their claims about real-world cognitive benefits.

Most nootropic supplements sold online have little or no rigorous evidence for cognitive enhancement in healthy adults. Some — like caffeine — have real and well-documented temporary performance effects, but these are not improvements in underlying cognitive capacity; they are transient shifts in alertness and attention that reverse completely when the substance clears. Others are essentially inert at marketed doses. The detailed evidence on brain training products and what genuinely transfers makes sober reading for anyone who has spent money in this category.

Intelligence-boosting music — the "Mozart Effect" — was essentially a myth that escaped the laboratory. The original 1993 study showed a brief improvement on one specific spatial reasoning task after listening to Mozart. It failed to replicate consistently and never supported the broader claims about ambient classical music improving general intelligence. It remains one of the most famous examples of a finding that became a cultural meme before the science had time to catch up with it.

Specific dietary supplements marketed as "IQ boosters" — ginkgo biloba, various B-vitamin megadoses, phosphatidylserine — have mostly failed to demonstrate meaningful effects in well-controlled trials on cognitively healthy adults. Ginkgo in particular has been extensively studied and consistently failed to produce the cognitive benefits its marketing implies.

Age and Cognitive Plasticity: When Does It Get Harder?

One of the most common questions about cognitive enhancement is whether it becomes harder — or impossible — after a certain age. The answer is more optimistic than most people expect, but with important nuances.

Fluid intelligence — the raw ability to reason through novel problems, hold information in working memory, and process information quickly — peaks in the mid-20s and declines gradually thereafter. This decline is real and not reversible through lifestyle interventions, though it can be meaningfully slowed. The rate of decline varies substantially between individuals and appears strongly influenced by the same factors that predict cognitive benefit at any age: exercise, sleep quality, social engagement, and intellectual challenge.

Crystallised intelligence — verbal knowledge, accumulated expertise, and pattern recognition built from experience — continues to grow well into the 60s and sometimes beyond for individuals who remain intellectually active. Many of the real-world cognitive advantages associated with high intelligence are in fact crystallised, which is why experienced professionals often outperform younger, higher-fluid-IQ counterparts on practical tasks in their domain.

The concept of cognitive reserve is also relevant here. Decades of research on neurodegenerative disease have established that individuals who maintain higher levels of cognitive activity throughout their lives develop a kind of resilience to age-related and pathological cognitive decline — their brains can tolerate more neurological damage before functional impairment becomes apparent. Education, lifelong learning, social engagement, and physical activity all contribute to this reserve. The implication is that cognitive enhancement efforts compound over time: a habit of intellectual challenge at 30 pays returns at 65 that no intervention at 65 can replicate.

The practical takeaway is that there is no age at which cognitive improvement efforts become futile. The nature of what is improvable shifts with age — fluid gains become harder to achieve but crystallised gains remain accessible, and protective effects on long-term cognitive health remain significant at any age.

The Role of Environment: What Holds People Back More Than Biology

Perhaps the most important finding from decades of intelligence research is how much environmental factors can suppress cognitive performance below a person's biological potential — and how correcting those factors can produce gains that dwarf anything achievable through deliberate enhancement programs.

Lead exposure during childhood is one of the most extensively documented environmental suppressors of IQ. Studies estimate that the reduction of leaded petrol in developed countries during the 1970s and 1980s raised average population IQ by several points — a larger effect than almost any targeted intervention. Environmental toxins including pesticides, mercury, and industrial pollutants have similar if less studied effects.

Early childhood adversity — chronic poverty, food insecurity, neglect, instability — has measurable effects on cognitive development that persist into adulthood. These are not simply social problems; they are neurological ones, mediated by chronic stress and nutritional deficiency during critical developmental windows. The implication is that for populations affected by these factors, addressing the environmental suppressors matters more than any enhancement program.

For adults in stable circumstances, the most common environmental suppressors of cognitive performance are the mundane ones: chronic sleep deficit, high sustained stress, sedentary lifestyle, social isolation, and lack of meaningful cognitive challenge at work or in leisure. These are correctable. Correcting them does not constitute "raising your IQ" in the strict measurement sense, but it absolutely constitutes improving cognitive function in ways that matter for real-world performance — which is, for most people, the thing they actually care about.

The relationship between intelligence and outcomes like income, educational attainment, and professional success is real but often overstated. Emotional intelligence, self-regulation, and interpersonal skill predict important life outcomes independently of IQ — and these are substantially more trainable than the narrow cognitive abilities measured by standardised tests.

Building a Personal Cognitive Enhancement Stack

Given everything the research shows, what does a genuinely evidence-based approach to cognitive improvement actually look like in practice? Not a 30-day program, not a supplement stack — a sustainable set of habits that compounds over months and years.

The foundation is non-negotiable: aerobic exercise four to five times per week, seven to nine hours of quality sleep, and nutritional adequacy covering iron, omega-3s, B vitamins, and vitamin D. These three factors, consistently maintained, create the neurobiological conditions under which all other cognitive work becomes more productive. Skipping any of them while pursuing elaborate enhancement strategies is like trying to optimise the performance of a car that is running on a flat tyre.

On top of that foundation, the highest-return cognitive investment for most adults is sustained intellectual challenge in domains that are genuinely novel and difficult. The key words are novel and difficult. Re-reading books in your existing domain expertise, or doing puzzles you already find easy, does not produce the kind of effortful processing that drives cognitive growth. Learning a new language, acquiring a skill in a completely different domain, engaging seriously with ideas that challenge your existing frameworks — these demand the kind of effortful cognitive work that research associates with genuine development.

Working memory training is worth considering if a cognitive assessment reveals working memory as a specific relative weakness. The evidence for general intelligence gains is weak, but the evidence for improvement in working-memory-demanding tasks is solid, and those tasks include most of what matters academically and professionally. Using a tool like the DesperateMinds advanced assessment to establish your current domain profile before choosing where to invest your cognitive development effort is considerably more efficient than guessing.

Finally, stress management should be treated as a cognitive intervention rather than a lifestyle luxury. Chronic stress is not just unpleasant — it is neurologically expensive, consuming prefrontal resources that would otherwise support reasoning, memory, and cognitive flexibility. Any sustainable program for cognitive enhancement that does not address chronic stress is working against itself.

The Honest Summary

You cannot hack your way to a significantly higher measured IQ in a few weeks. That is the honest answer, and it is worth being clear about it in a landscape full of people selling the opposite.

What you can do — through consistent, evidence-backed practice over months and years — is meaningfully improve the cognitive functions that IQ measures. Exercise, sleep, sustained intellectual challenge, stress management, and nutritional adequacy are not exciting. They do not have compelling marketing copy. But they are what the research actually supports, and the effect sizes for people who implement them seriously are not trivial.

More importantly: IQ is a measure of a specific set of cognitive skills under specific test conditions. The actual cognitive qualities that determine what you build with your mind — curiosity, persistence, creativity, the ability to synthesise across domains, the willingness to update your beliefs in response to evidence — are only partially captured by any standardised test. Improving your measurable cognitive performance is a worthy goal. So is developing the qualities that no test yet measures well.