Can You Increase Your IQ? What the Neuroplasticity Research Says

The Honest Answer Is: A Little, Under Specific Conditions

Few questions generate more wishful thinking in popular neuroscience than "can I increase my IQ?" The answer the evidence supports is nuanced, and it will disappoint anyone hoping for a dramatic uplift. Yes, cognitive ability is malleable to a meaningful degree. No, you cannot dramatically increase your IQ through brain training, nootropics, or most of the interventions aggressively marketed for this purpose.

Understanding what neuroplasticity actually means — and what it does not mean — is the starting point for a clear-eyed view of the question.

Understanding Neuroplasticity

Neuroplasticity refers to the brain's ability to change its structure and function in response to experience. This is genuinely remarkable and well-established. It includes:

• The formation of new synaptic connections (synaptic plasticity)
• The strengthening and weakening of existing connections through use and disuse
• Neurogenesis — the formation of new neurons, documented particularly in the hippocampus
• Cortical reorganisation following injury or sustained skill development

What neuroplasticity does not mean is that any type of cognitive exercise produces general improvements in intelligence. The brain changes it makes in response to experience are domain-specific. A taxi driver develops a larger hippocampal region associated with spatial navigation. A musician develops expanded auditory cortex representation. A chess grandmaster develops superior pattern recognition for chess positions. None of these adaptations reliably transfer to general IQ.

The taxi driver finding has actual research behind it. Eleanor Maguire at University College London studied London cab drivers — people who must pass "The Knowledge," a grueling exam requiring memorization of 25,000 streets. She found measurably larger posterior hippocampal volume in experienced drivers compared to controls, and the more years of experience, the more pronounced the structural difference. When cabbies retired, the difference gradually faded. The change was real, functionally specific, and partly reversible — none of which fits the story that challenging your brain produces permanent general enhancement.

The plasticity also changes across the lifespan in ways that matter for the IQ question. During early childhood, the brain operates under sensitive periods — windows of heightened plasticity for language acquisition, sensory processing, and foundational cognitive skills. This is why children acquire language effortlessly and adults rarely achieve native-level fluency in a second language acquired after puberty. Adult brains can still change substantially, but the same learning requires more time, more repetition, and produces more modest structural effects than it would have in childhood.

What Brain Training Research Shows

The brain training industry is built on a misapplication of neuroplasticity research. Companies like Lumosity have faced regulatory action for claims that their games improve real-world cognitive performance. The research reality is considerably more modest.

A landmark 2010 study by Owen and colleagues involving over 11,000 participants found that while extensive practice on brain training tasks improved performance on those specific tasks, there was no evidence of transfer to broader measures of cognitive function. You get better at the games. That improvement does not generalise.

What Moves the Needle

The interventions with the strongest evidence for improving real cognitive performance are disappointingly unglamorous:

• Aerobic exercise — Consistently the most evidence-backed cognitive intervention. Regular aerobic exercise increases BDNF (brain-derived neurotrophic factor), promotes hippocampal neurogenesis, and improves performance on fluid intelligence measures. Effects are modest — estimated at 3–5 IQ-equivalent points — but real and sustained.
• Sleep — Consistently getting 7–9 hours of quality sleep is one of the highest-impact things you can do for cognitive performance. The effects of chronic sleep restriction on fluid intelligence are well-documented and significant.
• Formal education and sustained learning — The Flynn Effect is partly attributable to expanding education. Learning new, complex skills — a second language, a musical instrument, a demanding technical field — does appear to produce some generalised cognitive benefits, particularly when the learning involves sustained effort over years.
• Reducing chronic stress — Cortisol causes structural damage to the hippocampus and prefrontal cortex. Eliminating sources of chronic psychological stress has documented protective and potentially restorative effects on cognitive function.

The Realistic Expectation

Across these evidence-backed interventions combined, a realistic upper bound for voluntary cognitive improvement is perhaps 5–10 IQ points. Not 30. Not 50. This is meaningful — 10 points is the difference between two IQ bands — but it requires genuine lifestyle investment, not a brain training subscription.

A more productive question than "how do I maximise my IQ?" is "how do I ensure my cognitive performance reflects my actual ability?" Many people operate significantly below their ceiling due to chronic sleep deprivation, high stress, and sedentary behaviour. Addressing these is not enhancement — it is removing suppression.

The Right Starting Point

Before worrying about optimisation, it is worth knowing your current baseline. A score taken under optimal conditions — well-rested, unstressed, focused — gives you the most accurate picture of where you actually are. That is the number worth building from.