Groups are often found to be more rational than individuals. In lying games, this implies that groups are more dishonest. We scrutinise this conclusion in a setup where there are true moral concerns associated with dishonest behaviour. In contrast to prior studies, we do not find groups to be...

In one-shot social dilemma experiments, cooperation rates dramatically increase if subjects are allowed to communicate before making a choice. There are two possible explanations for this "communication effect". One is that communication enhances group identity, the other is that communication...

People contribute more to experimental public goods the more others contribute, a tendency called "crowding-in." We propose a novel experimental design to distinguish two possible causes of crowding-in: reciprocity, the usual explanation, and conformity, a neglected alternative. Subjects are...

Using a repeated public goods game, we experimentally examine how apologies support mutual cooperation in groups. In two treatments where participants can send either public apologies or private apologies, contributions increase by 0.37 and 0.61 standard deviations respectively, compared to a...

Political identity has become the strongest social divide within Western societies. This paper employs experiments to measure discrimination along multiple dimensions of social identity, and replicates previous findings showing the strongest discrimination against out-groups occurs in the...