In recent decades, many researchers have studied the importance of group-level cognition. I strongly agree with the notion that group activities improve intellectual abilities. Indeed, to my mind, there is now convincing evidence that group activities improve the intelligence of individuals. In this essay, I shall examine how research in team games and study groups supports this view. To begin with, team games clearly require individuals to perform a diverse range of rapid mental calculations. This is because, in a sporting context, players must predict and anticipate possible actions within tight time constraints. For example, a recent Cambridge study showed that soccer players can – within the span of seconds – calculate over a dozen different permutations that could result from a single soccer- related action. Such predictive powers clearly improve players' mental abilities and result from activities performed in a group context. Secondly, study groups enable indi...