punishment behavior. Our study uses experiments conducted with 525 officers in the Swiss Army, and exploits random assignment to … prisoner's dilemma game with in-group as opposed to out-group members. They also use a costly punishment option to selectively … stronger in-group cooperation, but also a qualitative change in punishment: punishment becomes antisocial, harming cooperative …

candidate is expectations: what people expect could affect how they feel about what actually occurs. In a real-effort experiment …

take risks is negatively related to age and being female, and positively related to height and parental education. We test … the behavioral relevance of this survey measure by conducting a complementary field experiment, based on a representative …

hostility between groups. Our experiment provides the first evidence without the confounding effect of self-selection into … Army. We conduct choice experiments - simultaneous prisoner’s dilemma games, with and without third-party punishment - in … not lead to hostility, in the sense of vindictive punishment of outsiders, but does affect norm enforcement, enhancing …