Abstract
Cooperation requires that individuals are able to identify, and preferentially associate with, others who have compatible preferences and the shared background knowledge needed to solve interpersonal coordination problems. The present study investigates the nature of such similarity within social networks, asking: What do friends have in common? And what is the relationship between similarity and altruism? The results show that similarity declines with frequency of contact; similarity in general is a significant predictor of altruism and emotional closeness; and, specifically, sharing a sense of humor, hobbies and interests, moral beliefs, and being from the same area are the best predictors. These results shed light on the structure of relationships within networks and provide a possible checklist for predicting attitudes toward strangers, and in-group identification.
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Acknowledgments
This research is supported by the SOCIALNETS Project, funded by an EU-FP7 grant. RD’s research is also supported by the British Academy Centenary Research Project and by an ERC Advanced Grant. Thanks also to Susanne Shultz, and Thomas Pollett for statistical advice.
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Curry, O., Dunbar, R.I.M. Do Birds of a Feather Flock Together?. Hum Nat 24, 336–347 (2013). https://doi.org/10.1007/s12110-013-9174-z
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DOI: https://doi.org/10.1007/s12110-013-9174-z