We experimentally test the social motives behind individual participation in intergroup conflict by manipulating the framing and symmetry of conflict. We find that behavior in conflict depends on whether one is harmed by actions perpetrated by the out-group, but not on one’s own influence on...

In experiments, people behave more cooperatively when they are aware of an external threat, while in the field, we observe surprisingly high levels of cooperation and altruism within groups in conflict situations such as civil wars. We provide an explanation for these phenomena. We introduce a...

Bidding rules that guarantee procedural fairness may induce more equilibrium bidding and moderate other-regarding concerns. In our experiment, we assume commonly known true values and only two bidders to implement a best-case scenario for other-regarding concerns. The two-by-two factorial design...

This article examines the nature of human behavior in a nested social dilemma referred to as the Spillover Game. Players are divided into two groups with positive production interdependencies. Based on theoretically derived opportunistic, local, and global optima, our experimental results...

There is extensive literature, both theoretical and empirical, on the effects of social identity on a wide range of economic and non-economic outcomes. However, there is only scarce knowledge about how social identity is affected by policies or market structure. We address the question how...

We report on an experiment designed to explore whether and how anger affects future levels of cooperation. Participants play three consecutive one-shot games. In between two identical two-person public goods games there is a mini dictator game that, depending on the treatment, either gives or...

The provision of public goods regularly embodies interrelated spheres of influence on multiple scales. This article examines the nature of human behavior in a multilevel social dilemma game with positive provision externalities to local and global scales. We report experimental results showing...

We investigate experimentally the underlying motivations and individual differences with regard to the participation in between-group conflict in nested social dilemmas. In our nested social dilemmas, the collective is divided into two groups, and individuals allocate tokens between a private, a...

We study the existence of homophily (i.e. the tendency for people to make friends with people who are similar to themselves) with respect to trustworthiness. We ask whether two friends show similarly trustworthy behavior towards strangers, and whether this is anticipated by outsiders. We develop...

We report on an experiment designed to explore whether a written expression of disapproval affects future levels of cooperation. In between two identical public goods games, participants play a mini dictator game that, depending on the treatment, either gives or does not give the recipient the...