{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,6]],"date-time":"2026-10-06T17:38:20Z","timestamp":1791308300904,"version":"4.3.1"},"reference-count":30,"publisher":"American Association for the Advancement of Science (AAAS)","issue":"5850","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Science"],"published-print":{"date-parts":[[2007,10,26]]},"abstract":"<jats:p>Altruism\u2014benefiting fellow group members at a cost to oneself\u2014and parochialism\u2014hostility toward individuals not of one's own ethnic, racial, or other group\u2014are common human behaviors. The intersection of the two\u2014which we term \u201cparochial altruism\u201d\u2014is puzzling from an evolutionary perspective because altruistic or parochial behavior reduces one's payoffs by comparison to what one would gain by eschewing these behaviors. But parochial altruism could have evolved if parochialism promoted intergroup hostilities and the combination of altruism and parochialism contributed to success in these conflicts. Our game-theoretic analysis and agent-based simulations show that under conditions likely to have been experienced by late Pleistocene and early Holocene humans, neither parochialism nor altruism would have been viable singly, but by promoting group conflict, they could have evolved jointly.<\/jats:p>","DOI":"10.1126\/science.1144237","type":"journal-article","created":{"date-parts":[[2007,10,25]],"date-time":"2007-10-25T15:15:28Z","timestamp":1193325328000},"page":"636-640","source":"Crossref","is-referenced-by-count":886,"title":["The Coevolution of Parochial Altruism and War"],"prefix":"10.1126","volume":"318","author":[{"given":"Jung-Kyoo","family":"Choi","sequence":"first","affiliation":[{"name":"School of Economics and Trade, Kyungpook National University, 1370 Sankyuk-dong, Buk-gu, Daegu 702-701, Korea."},{"name":"Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 08571, USA; and Dipartimento di Economica Politica, University of Siena, Piazza San Francesco, 7, 53100 Siena, Italia."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Samuel","family":"Bowles","sequence":"additional","affiliation":[{"name":"School of Economics and Trade, Kyungpook National University, 1370 Sankyuk-dong, Buk-gu, Daegu 702-701, Korea."},{"name":"Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 08571, USA; and Dipartimento di Economica Politica, University of Siena, Piazza San Francesco, 7, 53100 Siena, Italia."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"221","reference":[{"key":"e_1_3_1_2_2","unstructured":"C. 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L. Axtell, J. M. Epstein, H. P. Young, in Social Dynamics S. Durlauf, H. P. Young, Eds. (MIT Press, Cambridge, 2001) pp. 191-211.","journal-title":"Social Dynamics"},{"key":"e_1_3_1_30_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.tpb.2005.12.002"},{"key":"e_1_3_1_31_2","unstructured":"We would like to thank the Behavioral Sciences Program at the Santa Fe Institute the Russell Sage Foundation and the University of Siena for support and Robert Boyd Ernst Fehr Steven Le Blanc Peter Richerson Robert Rowthorn Toshio Yamagishi Polly Wiessner and Elisabeth Wood for contributions to our research. The authors declare no competing interests."}],"container-title":["Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.science.org\/doi\/pdf\/10.1126\/science.1144237","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,1,10]],"date-time":"2024-01-10T04:19:58Z","timestamp":1704860398000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.science.org\/doi\/10.1126\/science.1144237"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2007,10,26]]},"references-count":30,"journal-issue":{"issue":"5850","published-print":{"date-parts":[[2007,10,26]]}},"alternative-id":["10.1126\/science.1144237"],"URL":"https:\/\/doi.org\/10.1126\/science.1144237","relation":{},"ISSN":["0036-8075","1095-9203"],"issn-type":[{"value":"0036-8075","type":"print"},{"value":"1095-9203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2007,10,26]]}}}