Cooperation is fundamental to human societies and widespread among animals, yet explaining how cooperative relationships persist without one party exploiting another remains a challenge. Although it is well established that altruism can be favoured when recipients are relatives or when they reciprocate, it is increasingly being recognized that many behaviours cannot be explained in these terms....

Five key problems of kinship networks are boundedness, cohesion, size and cohesive relinking, types of relations and relinking, and groups or roles. Approaches to solving these problems include formats available for electronic storage of genealogical data and representations of genealogies using graphs. P-graphs represent couples and uncoupled children as vertices, whereas parent-child links ar...

Knowledge of biological relatedness between samples is important for many genetic studies. In large-scale human genetic association studies, the estimated kinship is used to remove cryptic relatedness, control for family structure, and estimate trait heritability. However, estimation of kinship is challenging for sparse sequencing data, such as those from off-target regions in target sequencing...

It has been a challenge to understand the formation and roles of social groups or natural communities in the evolution of species, societies and real world networks. Here, we propose the hypothesis that homophyly/kinship is the intrinsic mechanism of natural communities, introduce the notion of the affinity exponent and propose the homophyly/kinship model of networks. We demonstrate that the ne...

The classification of kin into structured groups is a diverse phenomenon which is ubiquitous in human culture. For populations which are organized into large agropastoral groupings of sedentary residence but not governed within the context of a centralised state, such as our study sample of 83 historical Bantu-speaking groups of sub-Saharan Africa, cultural kinship norms guide all aspects of ev...

Introduction There were 27 quality studies on looked after children as determined by the project categorisation. Studies included children who were placed with non-related foster parents as well as those in kinship care; these are currently the placements of choice in Anglophone jurisdictions (Ainsworth and Thoburn 2014). Surveys have compared children’s material resources in different forms of...

Donor conception challenges conventional kinship idioms: the involvement of a gamete donor culturally raises questions about parentage and also the meaning of genetic heritage. Although there is now a growing body of literature exploring how people resorting to donor conception negotiate kinship and connectedness, this predominantly focuses on heterosexual couples. Little is yet known about how...

Helgason et al. (Reports, 8 February 2008, p. 813) reported a positive association between kinship and fertility in the Icelandic population. We point out that the data further suggest that fertility initially increases with kinship and then decays. This is supported by another large study on the Danish population suggesting a superposition of effects of inbreeding and outbreeding depression on...

The human ability to form large, coordinated groups is among our most impressive social adaptations. Larger groups facilitate synergistic economies of scale for cooperative breeding, such economic tasks as group hunting, and success in conflict with other groups. In many organisms, genetic relationships provide the structure for sociality to evolve via the process of kin selection, and this is ...