Increased alertness and moderate ingroup cohesion in bonobos’ response to outgroup cues

Brooks, James; van Heijst, Karlijn; Epping, Amanda; Lee, Seok Hwan; Niksarli, Aslihan; Pope, Amy; Clay, Zanna; Kret, Mariska E.; Taglialatela, Jared; Yamamoto, Shinya

Abstract

In a number of species, including humans, perceived outgroup threat can promote ingroup cohesion. However, the distribution and selection history of this association across species with varied intergroup relations remains unclear. Using a sample of 8 captive groups (N = 43 individuals), we here tested whether bonobos, like chimpanzees, show more affiliative ingroup behaviour following perception of outgroup cues (unfamiliar male long-distance vocalisations). We used comparable methods to our previous study of captive chimpanzees, and found that, although weaker, there was an association for more frequent social grooming in response to the outgroup condition than the control condition, alongside more alert posture and increased self-directed behaviour. This provides preliminary evidence for an ancestral origin to the proximate association between outgroup cues and ingroup cohesion, at least prior to the Pan-Homo split, and suggests the presence of intergroup competition in our last common ancestor.

Citation

Brooks, J., van Heijst, K., Epping, A., Lee, S. H., Niksarli, A., Pope, A., Clay, Z., Kret, M. E., Taglialatela, J., & Yamamoto, S. (2024). Increased alertness and moderate ingroup cohesion in bonobos’ response to outgroup cues. PLoS ONE, 19(8), Article e0307975. https://doi.org/10.1371/journal.pone.0307975

• Journal Article Type: Article
• Acceptance Date: Jul 15, 2024
• Online Publication Date: Aug 21, 2024
• Publication Date: 2024
• Deposit Date: Sep 11, 2024
• Publicly Available Date: Sep 11, 2024
• Journal: PLoS ONE
• Electronic ISSN: 1932-6203
• Publisher: Public Library of Science
• Peer Reviewed: Peer Reviewed
• Volume: 19
• Issue: 8
• Article Number: e0307975
• DOI: https://doi.org/10.1371/journal.pone.0307975
• Public URL: https://durham-repository.worktribe.com/output/2770666