There has been recently much interest and research on the possible cognitive and educational benefits of teaching chess. Chess is now part of the school curriculum (as an optional subject) in several countries and research on the educational effects of chess instruction is currently carried in the United Kingdom, Spain, Turkey, Germany and Italy. The European Parliament and the Spanish Parliament have supported the use of chess instruction in schools as an educational tool.
The explicit assumption behind these initiatives is that skills acquired through chess instruction transfer to other fields: They improve mathematical and reading skills, and they enhance general cognitive abilities such as concentration and intelligence. Is this assumption supported by the empirical evidence?
Ten years ago, Gobet and Campitelli (2006) reviewed the studies having researched the effects of chess instruction on youngsters’ academic and cognitive abilities. Three important points were highlighted in their conclusions. First, the available experimental evidence was sparse (just seven studies in thirty years, with only two published in peer-reviewed journals). Second, the conclusions of the studies reporting positive findings on the effectiveness of chess instruction were limited by the typically poor methodology used. Last but not least, the available research provided no explicit causal model explaining why chess should foster students’ academic skills. In fact, substantial research in educational psychology and the psychology of expertise strongly suggests that transfer of skills from a domain (e.g. chess) to another one (e.g. mathematics) is difficult and occurs only when there is an overlap between the source and the target domains (see Gobet, 2015, for a recent discussion). Thus, Gobet and Campitelli had to conclude that the educational benefits of chess instruction were not supported empirically and that they were not justified theoretically.
Today, research on the effects of chess instruction is healthier. There are more studies (between 30 and 40, depending on the selection criteria) and, in general, the methodological quality has improved. This is reflected by the fact that more studies have been published in peer-reviewed journals (ten since 2006). In addition, several explanations trying to account for the potential educational benefits of chess instructions have been provided. For example, chess practice may foster some general cognitive skills, such as executive functions, meta-cognition and general intelligence, which in turn improve students‘ academic performance. Alternatively, chess might promote some academic skill, such as mathematics, because it shares several elements with the target domain (e.g. the value of the pieces and basic arithmetic, the movement of the pieces and geometry).
Chess instruction in schools is on the rise, but are the benefits scientifically justified?
We therefore decided that it was time to carry out a rigorous, quantitative review of the available evidence. To do so, we used the most appropriate method: Meta-analysis (e.g. Schmidt & Hunter, 2015). Meta-analysis is a statistical procedure that allows one to merge the results of many studies regarding a particular topic – in our case, the benefits of chess instruction on educational outcomes – into a single quantitative measure representing the size of the overall effect of one variable (chess instruction) on another variable (educational outcomes). In education, effect sizes typically consist of the standardized difference in improvement between a treatment group and a controlled group.
One advantage of using meta-analysis is that it is possible to compare the effect size of chess instruction with other school interventions. In a seminal book, Hattie (2009) carried out a synthesis of more than 800 meta-analyses of studies having investigated educational interventions. The outcome was that most school interventions show a positive effect. In fact, 50% of educational interventions have an effect of at least 0.40, a result that can often be obtained by traditional didactics. Thus, to be convincing and offer real educational advantages, a study should obtain an effect size higher than 0.40 – what Hattie calls the “zone of desired effects.”
We collected all the studies assessing the effectiveness of chess instruction in improving academic (mathematics and reading) and cognitive skills (e.g. intelligence, focused attention, meta-cognition). Then, we calculated (a) an overall meta-analytic mean and (b) three meta-analytic means, one for cognitive-related skills, one for mathematical-related skills and one for reading-related skills. The studies had to meet precise inclusion criteria, such as reporting an intervention (no correlational study was incorporated) and including, at least, one control group. The criteria were satisfied by 24 studies, with a total of 5,221 participants (2,788 in the experimental groups and 2,433 in the control groups) and altogether 40 effect sizes. The number of effect sizes is larger than the number of studies because some studies included different measures (e.g. reading skill and mathematical ability), and thus more than one effect size.
The overall effect size was 0.34, indicating a moderate positive overall effect of chess instruction. More specifically, the effect sizes were 0.38 for mathematics, 0.33 for cognitive skills, and 0.25 for reading (see Figure 1). Finally, the analysis showed a direct relation between the duration of the chess intervention and the magnitude of the effect. When considering only the studies with more than 25 hours of chess instruction, the effect size was 0.43. (All these effects were statistically reliable, with p < .05 or less).
Figure 1. Histogram of the overall effect sizes in cognitive, mathematics, and reading skills.
Chess instruction seems to have a positive effect on children‘s cognitive and academic (especially mathematics) skills, but the effect is no more than moderate. This outcome may be important for the study of transfer of skills in psychology, but it sheds some doubts about the usefulness of chess as an educational tool. In fact, given that the median effect size of interventions in educational contexts is 0.40, there are many (more than 50%) better ways to improve children‘s skills than chess instruction. Moreover, nearly all the reviewed studies lack a do-other control group, and thus it is impossible to rule out the presence of confounding variables such as placebo effects, for example teacher’s motivation, teacher’s expectation and student’s enthusiasm induced by a novel activity.
However, the fact that the duration of chess instruction positively correlates with the size of the effects is an encouraging result. If the benefits of chess instruction were merely due to placebo effects, these effects would probably occur regardless of duration. This is because the occurrence of placebo effects depends on the participation in the activity, not on the circumstantial features of the activity. A concrete possibility is thus that chess instruction requires a certain minimum amount of time (about 25-30 hours) to show appreciable effects (above 0.40). Nonetheless, the lack of control for placebo effects is still a severe limitation in this field of research.
It is perhaps not surprising that chess is much like anything: you reap what you sow. The more time and effort invested, the greater the rewards, just as going to the gym will not magically make one fit, one must also sweat and strain. Still, the important takeway is that a serious time investment *will* yield palpable results.
In conclusion, our meta-analysis upheld the idea that chess instruction improves children’s cognitive and academic skills, but also raised doubt about the real effectiveness of such practice. Also, as pointed out above, it is not only a matter of if, but also of how much chess instruction enhances children’s skills. Therefore, future studies should (a) control for potential placebo effects; (b) systematically vary the length of instruction to find what the optimal duration is; and (c) evaluate whether chess instruction can offer educational advantages compared to other interventions, such as music, checkers and Go.
Gobet, F. (2015). Understanding expertise: A multidisciplinary approach. London: Palgrave.
Gobet, F., & Campitelli, G. (2006). Education and chess: A critical review. In T. Redman (Ed.), Chess and education: Selected essays from the Koltanowski conference (pp. 124-143). Dallas, TX: Chess Program at the University of Texas at Dallas.
Hattie, J. A. (2009). Visible learning: A synthesis of over 800 meta-analyses relating to achievement. New York: Routledge.
Sala, G., & Gobet , F. (2016). Do the benefits of chess instruction transfer to academic and cognitive skills? A meta-analysis. Educational Research Review, 18, 46-57. Article available online at http://www.sciencedirect.com/science/article/pii/S1747938X16300112
Schmidt, F. L., & Hunter, J. E. (2015). Methods of meta-analysis: Correcting error and bias in research findings (3rd Ed.). Newbury Park, CA: Sage.
About the authors
Giovanni Sala is a PhD candidate in Psychology at the University of Liverpool. He obtained a Bachelor in Philosophy of Science and a Master in Cognitive Sciences at the University of Milan. Sala’s research focuses on the psychology of expertise and educational psychology. His main interests are transfer of skills, experts’ memory and intelligence.
Fernand Gobet is Professor of Decision Making and Expertise at the University of Liverpool. He spent his first career as a chess player, playing for the Swiss national team and earning the title of an International Master. He then moved to a scientific career, receiving his PhD in psychology in 1992 from the University of Fribourg (Switzerland). He held research and academic positions at Carnegie Mellon University (Pittsburgh), the University of Nottingham and Brunel University (London) before taking a chair at the University of Liverpool. His numerous collaborators include Nobel Prize winning Herbert Simon (one of the founders of Artificial Intelligence) and Adriaan De Groot (the father of chess psychology). Gobet has extensively written on expertise, the acquisition of language and computer modelling. His latest book Understanding Expertise (2015, Palgrave/Macmillan), provides a multi-disciplinary study of the psychology, sociology, neuroscience and philosophy of expertise, with extensive references to chess research.
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Chess instruction in schools: A quantitative review
by Giovanni Sala and Fernand Gobet
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