Living Reference Work Entry

Encyclopedia of Evolutionary Psychological Science

pp 1-3

Date: Latest Version

Altruism Among Nonkin


Nonhuman reciprocal altruism


Nonkin altruism is helping nonrelatives at a cost to one’s lifetime reproductive success. By this definition, a strategy of nonkin altruism cannot evolve and persist. If an “altruistic” trait is adaptive, then “altruists” that pay a cost in the short-term to help a nonrelative must gain a net reproductive benefit in the long-term, in which case the behavior is not altruistic but rather mutually beneficial.


The concept of altruism is of great interest to both psychologists and evolutionary biologists, but it has different meanings in each context, which creates a semantic problem for the field of evolutionary psychology and other social sciences concerned with the evolution of human cooperation ( West et al. 2011). In psychology, altruism often refers to intentions and motivations to help others without regard to one’s own self-interest. In evolutionary biology, however, altruism refers to a behavior that increases the recipient’s ...

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