Keeping up appearances: Experiments on cooperation in social dilemmas

We cooperate. To be precise: we help out others at a cost to ourselves, daily and at an astonishing scale; among family, strangers and enemies, whether we are foraging, negotiating or waging war. Why are we willing to reduce our own chances of survival and reproduction to augment those of others?
This dissertation addresses such social dilemmas using laboratory experiments. It explores how we incorporate reputational concerns, whether imaginary competition with another group makes us more self-sacrificing, and why we behave more cooperatively if we can select our own partners. These institutions make us self-conscious of our appearance in comparison to others and boost cooperation in social dilemmas.