A group of researchers in Germany and Sweden recruited 39 competitive male chess players, who had an average IQ of 127 and an average chess Elo rating of about 1700 (an above-average rating in the system used to determine serious players’ skill level). They divided the group to test their performance after consuming either 200 mg of modafinil, 20 mg of ritalin, 200 mg of caffeine, or a placebo. Each participant then played 20 games against the computer which adjusted to their skill level. In each game, the participant had 15 minutes to make their moves. When they controlled for the extra time, however, they found that modafinil boosted performance by 15%, ritalin by 13%, and caffeine by 9%. The placebo, as expected, didn’t do anything. The researchers believe that cognitive enhancers were helping players perform more mental calculations and make better moves.
