We find support for coalition formation between individuals who share food & labour, & especially kinship; physically formidable men & men higher in informal status were more likely to provide coalitional support over time

Coalitions and conflict: A longitudinal analysis of men's politics. Daniel Redhead, Christopher R. von Rueden. Evolutionary Human Sciences, May 5 2021. https://www.cambridge.org/core/journals/evolutionary-human-sciences/article/coalitions-and-conflict-a-longitudinal-analysis-of-mens-politics/06D187167A6F3B1C7D2379D13D89BFA0

Abstract: To negotiate conflict and navigate status hierarchy, individuals in many species form coalitions. We describe inter-personal conflicts and assess theories of coalitionformation in a small-scale human society. Based on longitudinal and cross-sectional social network analysis of men in two communities of Tsimane forager-horticulturalists, we find evidence of reciprocity in coalitional support, as well as evidence of transitivity: an ally of my ally is likely to become my ally. We find mixed support for coalition formation between individuals who share a common adversary. Coalition formation was also predicted by food- and labour-sharing and especially by kinship. Physically formidable men and men higher in informal status were more likely to provide coalitional support over time; evidence was mixed that they receive more coalitional support. The highest status men are hubs of a dense coalitional support network that indirectly link all men in the community. These findings suggest male coalition formation is multiply motivated, and in general reveals the political dynamics that structure men’s lives in small, relatively egalitarian communities.

Media Summary: Among the Tsimane, the emergence of coalitions over time is primarily motivated by social status and existing social relationships between individuals.

Popular version https://www.eurekalert.org/pub_releases/2021-05/mpif-cac050521.php