When organisms can choose whom to interact with, it can create a biological market where
individuals need to outbid their rivals for access to cooperative relationships. Each …

Explanations of cooperation between non-kin in animal societies often suggest that
individuals exchange resources or services and that cooperation is maintained by …

In this thought-provoking book, the acclaimed author of Our Inner Ape examines how
empathy comes naturally to a great variety of animals, including humans. Are we our …

Somewhere in Africa, more than a million years ago, a line of apes began to rear their young
differently than their Great Ape ancestors. From this new form of care came new ways of …

Scientists have long counseled against interpreting animal behavior in terms of human
emotions, warning that such anthropomorphizing limits our ability to understand animals as …

Convergent evidence from many species reveals the evolutionary origins of human
friendship. In horses, elephants, hyenas, dolphins, monkeys, and chimpanzees, some …

The Handbook of Moral Development is the definitive source of theory and research on the
development of morality. Since the publication of the first edition, ground-breaking …

Within-group variation in sociality has been linked to correlates of fitness across vertebrates.
Individuals that form strong social bonds with a few partners, or are well integrated into a …

Sociality has positive effects on female fitness in many mammalian species. Among female
baboons, those who are most socially integrated reproduce most successfully. Here we test …

A growing body of evidence suggests that social bonds have adaptive value for animals that
live in social groups. Although these findings suggest that natural selection may favor the …