Face Masks Decrease Quality Of Chess Moves But Mostly Among Grandmasters

Wearing a face mask during a game of chess decreases the quality of chess players' decisions, an effect that is relatively short and mostly hurts strong players. This is the conclusion of a study about the effect of masks on cognitive performance by behavioral and development economist GM David Smerdon.

For his study, published in PNAS, Smerdon collected data from over 70 chess tournaments with mask requirements held during the pandemic. He matched those to another roughly 140 tournaments without masks but with a large overlap of the same players.

Overall, he analyzed almost three million chess moves played by more than eight thousand people in 18 countries and found that masks significantly decrease performance for grandmaster-level players, particularly in high-incentive tournaments. 

Earlier chess-related studies assumed a higher working memory load for stronger chess players. Based on this assumption, Smerdon tested in three different ways the prediction that the effect of wearing masks should be larger for stronger players, and each time this hypothesis was supported.

The study found that while mask-wearing had a negative impact on chess performance, the effect subsided after four to six hours of playing. In general, there’s no negative effect of masks at all for the average chess player.

"The decrease in performance was due to the annoyance caused by the masks rather than a physiological mechanism, but people adapted to the distraction over time," Smerdon said. "The results suggest that the effect of masks may depend on the type of task, the duration of the task and working memory load."

Although the use of face masks has been a key response to the COVID-19 pandemic, leading to the widespread use of masks in classrooms and offices around the world, almost nothing was known about their effects on cognitive performance. Using chess, Smerdon's study suggests that masks might decrease performance, especially in situations where there is a demanding mental task with a high working memory load.

"This is something to keep in mind for occupations in the STEM fields of science, technology, engineering and mathematics as well as other professions that demand a high level of working memory such as language interpreters, performers, waiters and teachers," said Smerdon.

The Australian grandmaster said understanding the impact of mask-wearing on decision-making could help individuals and organizations better evaluate when and how to use them: "For example, education policy makers may need to bear in mind the disruptive effects of masks when designing exam conditions to address concerns about student health and fairness."