we had wondered how mentalising ability affected our appreciation of jokes.

used to create the weaker bonds that hold together the outer layers of our communities.

Risk-taking and sportiness are other cues to which women seem to pay more than just casual attention.

We feel a sense of obligation to our friends and that sense of obligation seems to come from the fact that we spend a lot of time with them.

support clique is the people you see at least once a week, while the sympathy group consists of the people you see at least once a month.

Their butterfly patterns of interaction helped to keep the community integrated, allowing social information to flow from one side to the other.

there is something very different about primate social relationships that only a very small number of other mammals seem able to match.

the more gifts received, the less intimate the relationship, whereas the reverse was true for emotional support

the ‘act first, think after’ principle. The problem with this kind of behaviour is that relationships will only work if the benefits are fairly equally balanced.