Territoriality and Gender in the Laboratory

We investigate the behavior or males and females in an experimental Prisoner’s Dilemma game with a partisan audience. In each session, there are two same-gender groups, either both male, both female, or one group of males and one group of females. Groups are separated into two rooms; each period, the Prisoner’s Dilemma is played in each room. One player from the other room is seated across a table from a player from that room, with all other participants from that room seated behind the home player and observing. Each person plays twice, once at home and once on the road; to make group identity more salient, each person receives a 1/3 share of the payoffs from every outcome in which the person did not participate, so that most of one’s payoffs are derived from the actions of others. We find very different patterns of behavior across gender. While there is no significant difference in the overall cooperation rates for males and females, males cooperate substantially and significantly more often when on the road, while females cooperate substantially and significantly more often when at home. Our results constitute a puzzle not only for economic theory, but also for evolutionary psychology. While the latter predicts the home-away difference for males that we observe, it does not explain the pattern for females.