Why do we enjoy music? Group cohesion. Why do we dance? Group cohesion. But there a couple things wrong with that style of explanation. I'm very deeply suspicious of the explanation always says group cohesion. One of them is, group cohesion is not, in fact, what natural selection selects for. It selects for propagation of genes. Sometimes groups, cohesive groups can help the individuals that compose those groups, but if a group is too cohesive, you could be exploited by the group. You could be cannon fodder.