Does chess make children more intelligent? What the school trials show
Does chess raise children’s IQ? Nothing demonstrates it. A 2016 meta-analysis finds a moderate effect of chess lessons on school results, but this effect shrinks when studies are better designed, and the largest randomised trial, conducted in England among 4,009 pupils, finds no effect on mathematics. Chess remains an excellent pastime, not a shortcut to intelligence.
Far transfer: improvement in a skill remote from the one being trained, for example better results in mathematics after chess lessons. Near transfer, by contrast, concerns a neighbouring skill (improving at draughts after chess). The meta-analyses by Giovanni Sala and Fernand Gobet find far transfer to be small or nil.
Does chess raise children’s IQ? The trials
The question interests parents and ministries alike: several countries have introduced chess in schools in the hope of better results in mathematics. Researchers have therefore multiplied the studies. Here are the three most important.
The Sala and Gobet meta-analysis (2016)
Sala and Gobet, 2016 · Educational Research Review
Do the benefits of chess instruction transfer to academic and cognitive skills? A meta-analysis
- Who
- 24 studies, 40 effect sizes (2,788 pupils in the chess group, 2,433 controls)
- Type
- Meta-analysis · level of evidence: Moderate
- Result
- Moderate overall effect (g = 0.34), more marked in mathematics (0.38) than in reading (0.25), and stronger when the lessons last longer.
- What the study does not say
- No study had the ideal design (a no-activity control group and an active control group): a placebo effect is not ruled out.
At first sight, the result is encouraging. But the authors immediately pointed out the problem: without a control group doing another new and motivating activity, it is impossible to know whether the effect comes from chess or simply from novelty, adult attention and the pupils’ enthusiasm.
The English randomised trial by the Education Endowment Foundation
Jerrim et al., 2018 (EEF trial) · Journal of Human Resources
Does Teaching Children How to Play Cognitively Demanding Games Improve Their Educational Attainment? Evidence from a Randomized Controlled Trial of Chess Instruction in England
- Who
- 4,009 pupils aged 9 to 10, 100 English schools
- Type
- Cluster-randomised trial by school (funded by the Education Endowment Foundation) · level of evidence: High
- Result
- 30 hours of chess lessons in 2013-2014 (one hour a week): no measurable effect on results in mathematics, reading or science a year later (effect size of 0.01 in mathematics).
- What the study does not say
- A single programme, a single duration; the effects on enjoyment or concentration in class were not the main focus.
This is the strongest study to date: chance chose the schools that received the lessons, and results were measured by national examinations, independent of the researchers. Its verdict is unequivocal for mathematics. It does not say the lessons were useless (the pupils learned to play, which was the first objective), but that they did not improve school results.
The Spanish study from La Laguna (2012)
Aciego, García and Betancort, 2012 · The Spanish Journal of Psychology
The Benefits of Chess for the Intellectual and Social-Emotional Enrichment in Schoolchildren
- Who
- 170 pupils aged 6 to 16 in a chess club, 60 in football or basketball
- Type
- Quasi-experimental study over a school year · level of evidence: Low to moderate
- Result
- Clearer progress in the chess group on the WISC-R and on measures of problem-solving and socio-emotional adjustment, according to the pupils and their teachers.
- What the study does not say
- The pupils chose their activity (no random allocation); the authors note that the profile of children who choose chess weighs on the results.
This study is often cited to defend chess in schools. It has the merit of comparing with other extracurricular activities, but the children had chosen their activity: those who choose chess are not necessarily the same as those who choose football.
The later syntheses
Sala and Gobet, 2017 · Current Directions in Psychological Science · DOI 10.1177/0963721417712760
Does far transfer exist? Negative evidence from chess, music, and working memory training
- Who
- Synthesis of meta-analyses
- Type
- Review of meta-analyses · level of evidence: High
- Result
- The effects of chess lessons, music or working-memory training on other skills are small and shrink as methodological quality increases: far transfer is rare.
- What the study does not say
- Mainly concerns children and school skills.
The school trials in one table
| Study | Sample size | Duration | Random allocation | Effect measured |
|---|---|---|---|---|
| Aciego et al., 2012 (Spain) | 170 pupils in chess, 60 in sport | One school year | No | Gains on the WISC-R and in socio-emotional adjustment |
| Sala and Gobet, 2016 (meta-analysis) | 24 studies, ≈ 5,200 pupils | Variable | Rarely | g = 0.34; stronger in maths, stronger if lessons are longer |
| Jerrim et al., 2018 (England, EEF) | 4,009 pupils, 100 schools | 30 hours over a year | Yes | No effect in maths, reading or science |
All these studies appear, with their full references, in the annotated bibliography.
Why the results diverge
- The placebo effect and novelty. A new lesson, led by an enthusiastic instructor, motivates pupils. This enthusiasm can temporarily improve results, whatever the activity.
- Selection. When children or schools choose to do chess, the most motivated or the most advantaged are over-represented.
- Publication bias. Studies that find an effect are published more often than those that do not.
- Duration. Sala, Foley and Gobet (2017) estimate that at least 25 to 30 hours of lessons are needed to hope for an effect; some studies offer far fewer.
The underlying mechanism lies in the nature of expertise. What one learns in chess is mainly patterns specific to chess, as we explain on the page chess and memory. They serve to play better, not directly to calculate better in class.
What chess brings to a child
If chess does not raise IQ, it remains a very good pastime. Parents and teachers often cite:
- the pleasure of a game in which you visibly improve;
- learning patience and respect for your opponent;
- the ability to lose, analyse your defeat and start again;
- links between generations: grandparents and grandchildren play on almost equal terms after a few years.
These benefits are plausible and appreciated, but they have not been measured rigorously. The question of attention, often put forward, is dealt with on the page chess and ADHD.
Chess in schools in Europe
On 15 March 2012, the European Parliament adopted a written declaration (No 50/2011) on the introduction of the “Chess in School” programme in the education systems of the Union, signed by a majority of MEPs. It invites the Commission and the Member States to encourage this programme. A written declaration is not binding: it shows political support, not scientific proof of effectiveness.
At what age should you start chess?
No study sets an ideal age. In practice, many children start around 5 or 6, when they can follow rules and stay seated for a short game. Clubs often offer lessons from this age, with simplified forms (the pawn game, mini-games). More important than age: enjoyment. A bored child will give up; a child who is having fun will improve.
At home, a real board remains the best start: you play together, discuss the moves, put the pieces away. A wooden chess set for the family, with stable, easily recognised pieces, will accompany a child for years.
What the studies do not say
- That chess would be harmful: no study suggests it.
- That longer or more intensive lessons could not have an effect: that remains to be tested in well-controlled trials.
Frequently asked questions
Does chess raise children’s IQ?
Nothing demonstrates it. Meta-analyses find modest effects that shrink when studies are better controlled, and the largest randomised trial, among 4,009 English pupils, finds no effect on school results.
At what age should you start chess?
Around 5 or 6 for many children, when they can follow rules. No study sets an ideal age: the pleasure of playing matters more than the starting age, and you can start at any age.
Can playing chess raise IQ?
Studies do not show a lasting increase in IQ, in children or adults. People mainly improve at chess itself; transfer to other intellectual abilities is small or nil according to the syntheses by Sala and Gobet.