Reproductive inequality, or reproductive skew, drives natural selection, but has been difficult
to assess, particularly for males in species with promiscuous mating and slow life histories …

Humans exhibit major age-related shifts in social relationships along with changes in social
and emotional psychological processes that underpin these behavioural shifts. Does social …

When Darwin proposed that females shape evolution by being choosy in their choice of
male suitors, his Victorian contemporaries were shocked that he accorded so much …

Demographic data on wild chimpanzees are crucial for understanding the evolution of
chimpanzee and hominin life histories, but most data come from populations affected by …

How can collective action evolve when individuals benefit from cooperation regardless of
whether they pay its participation costs? According to one influential perspective, collective …

In most male mammals, fitness is strongly shaped by competitive access to mates, a non-
shareable resource. How, then, did selection favor the evolution of cooperative social …

Objectives Although conflicts between groups over valuable resources are common in the
animal kingdom, an individual's strategy toward out‐group individuals may differ according …

Recent research on primates and other taxa has shown that the relationships individuals
form with members of the same sex affect their reproductive success. Evidence showing that …

In many group-living mammals, mothers may increase the reproductive success of their
daughters even after they are nutritionally independent and fully grown [1]. However …

Highlights•Some species form social bonds that facilitate cooperation and provide
benefits.•Adult male chimpanzees form some of the strongest and most stable social …