Prosocial values and group assortation - Within an N-person prisoner's dilemma game

Ninety-five freshmen each recruited three peers to play a "group bidding ga me," an N-person prisoner's dilemma in which anyone could win movie tickets depending on their scores in the game. Prior to playing, all participants completed a measure of prosocial value orientation. Replicating and extendi ng: earlier findings (Sheldon and McGregor 2000), our results show that pro social participants were at a disadvantage within groups. Despite this vuln erability, prosocial participants did no worse overall than asocial partici pants because a counteracting group-level advantage arose for prosocials, w ho tended to be concentrated in groups. Implications of this assortative pr ofess for the egoism/altruism debate, and for hierarchical selection theory , are discussed.