Human social behaviour might be unique in the animal kingdom. The fact that we cooperate on a large scale with nonkin might be underlain by psychological mechanisms not seen in other species. A key aspect of our sociality is prosocial behaviour, acts that are intended to produced benefits for others.
The psychology behind prosociality involves other-regarding concerns. When aligned with the welfare and emotional states of others, these lead to acts such as helping and sharing.
On the other hand, “feeling into” others can be misaligned so that we take pleasure in the misfortunes of others, leading to acts of spite and cruelty. In between, these social motivations can produce a sense of fairness and punitive sentiments. To explore the evolution of prosociality, fairness, punishment and spite, my research has used experimental approaches, many borrowed from experimental economics, to test chimpanzees and children.
The key insights from this work are that concern for the welfare of others – both for better and for worse – may be uniquely human, the capacities for which emerge early in our lives. One suggestion is that human sociality is not only uniquely hyper-cooperative, it is also hyper-competitive.