The human social world is orders of magnitude smaller than our highly urbanized world
might lead us to suppose. In addition, human social networks have a very distinct fractal …

Comparative analyses are the backbone of evolutionary analysis. However, their record in
producing a consensus has not always been good. This is especially true of attempts to …

Evolutionary explanations for mammalian sociality typically center on inclusive-fitness
benefits of associating and cooperating with close kin, or close maternal kin as in some …

Cooperative breeding is an extreme form of cooperation that evolved in a range of lineages,
including arthropods, fish, birds, and mammals. Although cooperative breeding in birds is …

The evolution of cooperative breeding has been traditionally attributed to the effect of kin
selection. While there is increasing empirical evidence that direct fitness benefits are …

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

Predation risk is a major ecological factor selecting for group living. It is largely ignored,
however, as an evolutionary driver of social complexity and cooperative breeding, which is …

The general belief that cooperation and altruism in social groups result primarily from kin
selection has recently been challenged, not least because results from cooperatively …

How can the stunning diversity of social systems and behaviours seen in nature be
explained? Drawing on social evolution theory, experimental evidence and studies …

Altruism is globally associated with unpredictable environments, but we do not understand
why. New theory has highlighted that unpredictable environments could favor the evolution …