The relative importance of social evolution theories such as kin selection, direct reciprocity and need-based transfers in explaining real-world cooperation is the source of much debate. Previous field studies of cooperation in human communities have revealed variability in the extent to which each of these theories explains human sociality in different contexts. We conducted multivariate socia...

Darwinian selection should preclude cooperation from evolving; yet cooperation is widespread among organisms. We show how kin selection and reciprocal altruism can promote cooperation in diverse 2×2 matrix games (prisoner's dilemma, snowdrift, and hawk-dove). We visualize kin selection as non-random interactions with like-strategies interacting more than by chance. Reciprocal altruism emerges f...

24 a younger age and were more likely to have a second child than women with less contact with kin. This suggests that, indeed, being around the family promotes behaviors, norms, and ideas that support fertility and heteronormative behavior. Kin-based societies will maintain norms that discourage homosexual behavior. Newson and Richerson (this issue) provide a validated model suggesting that, o...

In steady state Twin GP both children created by sub-tree crossover and point mutation are used. They are born together and die together. Evolution is little changed. Indeed fitness selection using the twin’s co-conceived doppelganger is possible.

Patients with white matter lesions (WMLs) often present with problems of balance. The aim of this study was to verify the effects of combined Pro-kin system and conventional balance training to improve balance ability in WMLs patients.This is a randomized controlled study, and 40 participants were divided into 2 groups: the intervention group (n=18) received Pro-kin system with additional conve...

This article investigates the targeting of cyclone relief within villages in Fiji. It focuses on how relief allocation is linked with informal risk sharing and elite capture, both of which are directly related to kinship. The results are as follows. First, food aid is initially targeted toward kin groups according to their aggregate shocks and then shared among group members. Right after the cy...

OBJECTIVES This study examined the extent to which older adults in the Netherlands include a nonrelative as part of their family (create fictive kin), and whether this process is similar in other age groups. It assessed the importance of absence of close family ties and the experience of divorce in the family network for the creation of fictive kin. METHOD Using data from the Netherlands Kins...

A major challenge for social theory is to explain the importance of kin discrimination for the evolution of altruism. One way to assess the importance of kin discrimination is to test its effects on increasing relatedness within groups. The social amoeba Dictyostelium discoideum aggregates to form a fruiting body composed of dead stalk and live spores. Previous studies of a natural population s...

The division of labor has typically been portrayed as a complementary strategy in which men and women work on separate tasks to achieve a common goal of provisioning the family. In this paper, we propose that task specialization between female kin might also play an important role in women's social and economic strategies. We use historic group composition data from a population of Western Dese...