Department of Psychology, Durham University, Durham, DH1 3LE, UK.
Durham Cultural Evolution Research Centre, Durham University, Durham, DH1 3LE, UK.
Learn Behav. 2023 Mar;51(1):48-58. doi: 10.3758/s13420-023-00570-8. Epub 2023 Feb 1.
Male and female human social bonding strategies are culturally shaped, in addition to being genetically rooted. Investigating nonhuman primate bonding strategies across sex groups allows researchers to assess whether, as with humans, they are shaped by the social environment or whether they are genetically predisposed. Studies of wild chimpanzees show that in some communities males have strong bonds with other males, whereas in others, females form particularly strong intrasex bonds, potentially indicative of cultural differences across populations. However, excluding genetic or ecological explanations when comparing different wild populations is difficult. Here, we applied social network analysis to examine male and female social bonds in two neighbouring semiwild chimpanzee groups of comparable ecological conditions and subspecies compositions, but that differ in demographic makeup. Results showed differences in bonding strategies across the two groups. While female-female party co-residence patterns were significantly stronger in Group 1 (which had an even distribution of males and females) than in Group 2 (which had a higher proportion of females than males), there were no such differences for male-male or male-female associations. Conversely, female-female grooming bonds were stronger in Group 2 than in Group 1. We also found that, in line with captive studies but contrasting research with wild chimpanzees, maternal kinship strongly predicted proximity and grooming patterns across the groups. Our findings suggest that, as with humans, male and female chimpanzee social bonds are influenced by the specific social group they live in, rather than predisposed sex-based bonding strategies.
男性和女性的人类社交结合策略不仅受到遗传因素的影响，还受到文化塑造的影响。研究不同性别的非人类灵长类动物的结合策略可以让研究人员评估它们是受社会环境影响，还是受遗传因素影响。对野生黑猩猩的研究表明，在一些群体中，雄性与其他雄性之间有很强的联系，而在另一些群体中，雌性之间形成了特别强烈的内部性别联系，这可能表明不同种群之间存在文化差异。然而，在比较不同的野生种群时，排除遗传或生态解释是很困难的。在这里，我们应用社会网络分析来研究两个相邻的半野生黑猩猩群体中雄性和雌性的社交联系，这两个群体具有相似的生态条件和亚种组成，但在人口结构上存在差异。研究结果表明，这两个群体的结合策略存在差异。虽然在雄性和雌性比例均衡的群体 1（Group 1）中，雌性之间的群体居住模式明显比雄性比例较高的群体 2（Group 2）更紧密，但在雄性之间或雄性与雌性之间的联系中没有这种差异。相反，在群体 2 中，雌性之间的梳理关系比群体 1 更紧密。我们还发现，与圈养研究一致，但与野生黑猩猩的研究相反，母婴亲缘关系强烈预测了群体之间的接近程度和梳理模式。我们的研究结果表明，与人类一样，雄性和雌性黑猩猩的社交联系受到它们所处的特定社交群体的影响，而不是受基于性别的先天结合策略的影响。
