Close social associations in animals and humans: functions and mechanisms of friendship

In: Behaviour
View More View Less
  • 1 Department of Behavioural Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands;, Email:
  • | 2 Department of Behavioural Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands, Department of Ethology Research, Biomedical Primate Research Centre, Rijswijk, The Netherlands
  • | 3 Department of Sociology, University of Groningen, Groningen, The Netherlands
Download Citation Get Permissions

Access options

Get access to the full article by using one of the access options below.

Institutional Login

Log in with Open Athens, Shibboleth, or your institutional credentials

Login via Institution


Buy instant access (PDF download and unlimited online access):



Both humans and group-living animals associate and behave affiliatively more with some individuals than others. Human friendship has long been acknowledged, and recently scientists studying animal behaviour have started using the term friendship for close social associates in animals. Yet, while biologists describe friends as social tools to enhance fitness, social scientists describe human friendship as unconditional. We investigate whether these different descriptions reflect true differences in human friendship and animal close social associations or are a by-product of different research approaches: namely social scientists focussing on proximate and biologists on ultimate explanations. We first stress the importance of similar measures to determine close social associations, thereafter examine their ultimate benefits and proximate motivations, and discuss the latest findings on the central-neural regulation of social bonds. We conclude that both human friendship and animal close social associations are ultimately beneficial. On the proximate level, motivations for friendship in humans and for close social associations in animals are not necessarily based on benefits and are often unconditional. Moreover, humans share with many animals a similar physiological basis of sociality. Therefore, biologists and social scientist describe the same phenomenon, and the use of the term friendship for animals seems justified.

Content Metrics

All Time Past Year Past 30 Days
Abstract Views 1639 748 29
Full Text Views 428 86 9
PDF Views & Downloads 347 102 15