The Bluegill Game: How Do Team and Individual Sports Specialists Play the “Bluegill Game”? An Illustration of a Perverse Side Effect of Altruism

In a sports hall, three different groups of young adults played the "bluegill game" (a Prisoner's Dilemma-like sports game). The present study's objective was to measure the extent of cooperative behaviour in a group of 25 team sports players. To maximise gains, a player had to adopt selfish tactics half the time. The group of team sports players came closest to this mixed-strategy Nash equilibrium (chi2=4.07 in a logistic regression, p<0.05). The two control groups (23 individual sports players and 24 non-sportspeople) were found to be significantly more cooperative. The altruistic players kept the game alive while working towards their own defeat. We discuss how the "bluegill game" model can be broadened to other social situations. In these non-collaborative, non-zero-sum games, cooperation is an irrational choice on the individual level but is essential on the group level.