Wildlife Research Center, Kyoto University, 6068203 Kyoto, Japan; Kumamoto Sanctuary, Kyoto University, 8693201 Kumamoto, Japan.
Kumamoto Sanctuary, Kyoto University, 8693201 Kumamoto, Japan; Center for the Advanced Study of Collective Behaviour, University of Konstanz, 78464 Konstanz, Germany; Max-Planck Institute of Animal Behavior, 78315 Radolfzell, Germany.
Horm Behav. 2022 Jul;143:105182. doi: 10.1016/j.yhbeh.2022.105182. Epub 2022 May 7.
Previous research has found that oxytocin (OT) is associated with intergroup behaviour in humans as well as wild chimpanzees, and that exogenous OT affects Pan social attention. The two Pan species, bonobos and chimpanzees, differ drastically from one another in their intensity of intergroup competition, with lethal intergroup aggression often led by males in chimpanzees and more tolerant associations often centered around females in bonobos. However, it remains unclear how exogenous OT changes the two species' responses to ingroup and outgroup individuals. In this study, after intranasal administration of nebulized OT or placebo control, chimpanzees and bonobos viewed image pairs of ingroup and outgroup conspecifics while their eye movements were tracked with an eye-tracker. Although the overall effect of OT was small, we found that OT shifted bonobos' and chimpanzees' attention to outgroup images of the sex primarily involved in intergroup encounters in each species. Specifically, OT selectively shifted attention towards outgroup photos of female conspecifics in bonobos, and those of outgroup male conspecifics in chimpanzees. This suggests that OT generally promotes outgroup attention in both bonobos and chimpanzees but this effect is restricted to the sex most relevant in intergroup relations. These results suggest that, although OT may have a generally conserved role in hominid intergroup behaviour, it may act in species-relevant ways under the influence of their socio-ecological backgrounds.
先前的研究发现，催产素（OT）与人类和野生黑猩猩的群体间行为有关，外源性 OT 影响 Pan 的社会注意力。两个 Pan 物种，倭黑猩猩和黑猩猩，在群体间竞争的激烈程度上有很大的不同，黑猩猩中雄性经常发起致命的群体间攻击，而倭黑猩猩中更多的是围绕雌性的容忍性联系。然而，外源性 OT 如何改变这两个物种对同群体和外群体个体的反应仍不清楚。在这项研究中，在经鼻给予雾化 OT 或安慰剂对照后，黑猩猩和倭黑猩猩观看了同群体和外群体同种个体的图像对，同时用眼动追踪器跟踪他们的眼球运动。尽管 OT 的总体效果很小，但我们发现 OT 改变了黑猩猩和倭黑猩猩对每个物种中主要参与群体间接触的性别的外群体图像的注意力。具体来说，OT 选择性地将注意力转移到倭黑猩猩中同群体雌性照片上，以及黑猩猩中同群体雄性照片上。这表明 OT 通常会促进黑猩猩和倭黑猩猩对外群体的关注，但这种效果仅限于群体间关系中最相关的性别。这些结果表明，尽管 OT 可能在人类群体间行为中具有普遍保守的作用，但在它们的社会生态背景的影响下，它可能以物种相关的方式发挥作用。
