In many social animals, individuals derive fitness benefits from close social bonds, which are often formed among kin of the philopatric sex. Hamadryas baboons, however, exhibit a hierarchical, multilevel social system where both sexes disperse from their natal one-male-unit (OMU). Although this would seem to hinder maintenance of kin ties, both sexes appear largely philopatric at the higher or...

Kin selection theory, also known as inclusive fitness theory, has been the subject of much debate and misunderstanding. Nevertheless, the idea that relatedness among individuals can drive the evolution of altruism has emerged as a central paradigm in evolutionary biology. Or has it? In two recent articles, E.O. Wilson argues that kin selection should no longer be considered the main explanation...

Darwinian evolution, defined as evolution arising from selection based directly on the properties of individuals, does not account for cultural constructs providing the organizational basis of human societies. The difficulty with linking Darwinian evolution to structural properties of cultural constructs is exemplified with kinship terminologies, a cultural construct that structures and delinea...

Human kinship and associated terminology vary a lot across cultures, but many anthropologists have suspected that a common set of principles underlies this variation. I argue that cross-cultural variation in kin classification is produced by a generative psychology built on two broad classes of rules. Some rules declare that kin differing with respect to binary distinctive features should be di...

OBJECTIVES Marriages among kin have the dual effect of both increasing average group relatedness as well as reducing the total number of kin by eliminating more genealogically and geographically distant individuals from kinship networks. Marriage decisions therefore face a tradeoff between density of kin, or formation of intensive kinship systems, and the diversity of kin, or extensive kinship ...

With evolutionary psychology used as the theoretical framework, two aspects of gift giving among young adults are investigated: (a) sex differences in motives for giving gifts to a romantic partner, and (b) the allocation of gift expenditures among various relations, including romantic partners, close friends, close kin, and distant kin members. As per the evolved sex differences in mating stra...

Social Hymenoptera have played a leading role in development and testing of kin selection theory. Inclusive fitness models, following from Hamilton's rule, successfully predict major life history characteristics, such as biased sex investment ratios and conflict over parentage of male offspring. However, kin selection models poorly predict patterns of caste-biasing nepotism and reproductive ske...

Kin recognition by the roots of Cycas edentata was recently demonstrated. Our extensive literature search revealed this to be the first report of kin recognition in any spermatophyte other than angiosperms. Based on this new validation that the phenomenon occurs among phylogenetically diverse taxa, we conclude that kin recognition by roots may be an ancient phenomenon.

The aim of this experimental study was to investigate kin discrimination in the polecat and to analyse the ontogeny of interactions. Juvenile polecats (ten males and nine females) had been raised under four distinct experimental conditions: 1, kin, familiar; 2, kin, unfamiliar; 3, non-kin, familiar; 4, non-kin, unfamiliar. During dyadic encounters between polecats in neutral enclosures, the num...