Do Video Games Rot Your Brain? What a Study of 9,855 US Children Found

Do video games rot your brain? The best large studies we read say no. The biggest on children, by Sauce and colleagues in 2022, tested 9,855 US children aged 9 to 10, and about 5,400 were retested two years later. Children who gamed more gained more on the intelligence measures: a standardised gain of 0.17, which the authors convert to 2.55 IQ points. The design was observational, so it cannot prove cause, and it covers US children only.

Below: what that study found for gaming, watching videos and socialising, what two other large studies add, whether games raise IQ or only the skills you practise, what counts as too much gaming, and what none of the studies cover.

Do video games rot your brain?

So can video games rot your brain? Not in the large studies we read. Sauce, Liebherr, Judd and Klingberg (Scientific Reports, 2022) used the Adolescent Brain Cognitive Development (ABCD) study, which follows children at 21 research sites across the United States and collects biological, psychological and social measures. They measured intelligence at ages 9 to 10 and again about two years later, and they allowed for each child's genetic score for cognition and family socioeconomic status.

• At ages 9 to 10: gaming time did not correlate with intelligence. Time watching videos correlated at r = -0.12 and time socialising on screens at r = -0.10
• Two years later, gaming: standardised beta +0.17, which the authors convert to 2.55 IQ points
• Two years later, watching videos: beta +0.12, or 1.8 IQ points. It was not significant when parental education replaced the socioeconomic score
• Two years later, socialising on screens: no effect

A standardised beta of 0.17 is a gain of 0.17 of a standard deviation (SD), the usual spread of scores. On a scale with mean 100 and SD 15, that is the 2.55 points the paper gives. By our arithmetic, 2.55 points moves a child from the 50th percentile to about the 57th. That is a small shift, and it is a gain, not a loss. Our IQ percentile calculator shows how little a rank moves for a gap that size.

The authors call the result evidence of a beneficial effect of gaming. It is still not a randomised trial. Children were not assigned to play more or less, so something else about them could explain the gain.

Where does the brain rot idea come from? Oxford University Press named "brain rot" its 2024 Word of the Year after more than 37,000 people had their say. It defines the term as low-quality online content and the negative effect people think it has. That is a word's popularity, not a finding, and in this study watching videos was not linked to a loss either.

Are video games good for your brain? What did the large studies find?

Some skills look better in gamers, but the evidence that games lift general ability is weak. Two other studies show both sides, so are video games good for your brain? It depends on the skill and the design.

Chaarani and colleagues (JAMA Network Open, 2022) also used ABCD data, this time 2,217 children aged 9 to 10. How do video games affect the brain? They compared children who played at least 21 hours a week with children who never played. Gamers did better on two brain-scan tasks, one of response inhibition and one of working memory, and showed different activity in some brain regions. The authors say the findings are consistent with gaming improving these abilities. The comparison was made at one point in time, so by our reading it cannot rule out that children who are good at these tasks choose to play more.

Sala, Tatlidil and Gobet (Psychological Bulletin, 2018) ran three meta-analyses, which pool many studies, to test the effect of video games on the brain, measured as cognitive ability. The first pooled 310 results on the link between game skill and cognitive ability, the second 315 on gamers versus non-gamers, and the third 359 on training. Effects were small or null in all three. The authors found no evidence of a causal relationship between playing video games and better cognitive ability.

So do video games help your brain? Gamers in the ABCD sample did better on specific tasks, but the pooled experiments find little carry-over to general ability. The two results do not contradict each other. A skill can be better in people who play without games being what made them better.

Do video games raise IQ, or only the skills you practise?

The meta-analysis points to the skills you practise. Researchers call carry-over to similar skills near transfer and carry-over to general ability far transfer. Sala and colleagues note that far transfer is hard to obtain in many fields, and say video game training is no exception.

The Sauce result sits at the other end. It suggests a link between gaming and a gain on a broad intelligence measure, but it cannot say whether games caused it. Our blog guide on whether video games raise your IQ covers the narrower skills where gains are clearer, and our news guide to brain training apps sets the same question against the wider training literature.

The same question comes up for other pastimes, and the answers rhyme. Our guide to the Mozart effect finds a short-lived boost on one spatial task, not a rise in IQ. Our guide to whether Sudoku increases IQ finds people who do number puzzles score higher, but no study shows the puzzles caused it. A practised skill, a link in a survey and a proven gain in general ability are three different things.

How much gaming is too much, and what do these studies not cover?

No study here sets a safe number of hours. The World Health Organization defines gaming disorder by its effects, not by time played: impaired control over gaming, gaming taking priority over other interests and daily activities, and continuing despite negative consequences. It must cause significant impairment and normally be evident for at least 12 months. WHO says it affects only a small proportion of people who game.

The limits matter as much as the results. Sauce and colleagues relied on children's self-reported screen time and could not separate game types, because the ABCD study records gaming as one variable covering simple phone games and complex multiplayer ones. The genetic score came from a study biased towards people of European descent. The authors say their results may not carry over to other countries, since children differ in the games they prefer. Ages covered were 9 to 12.

Nothing here speaks to adults, to teenagers, or to Europe. Other screen habits are covered in our guide to screen time and cognitive test scores in children, and our guide to brain myths about intelligence sets this question beside other popular claims. You can try a game-style measure yourself with our reaction time test or the brain games.

For a measured result rather than a headline, take the IQ Metrics test. Games and screens can change how you spend time, but a norm-referenced test is what reports a rank.

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