Department of Evolutionary Studies of Biosystems, School of Advanced Sciences, The Graduate University for Advanced Studies, Sokendai, Hayama, Kanagawa, 240-0193, Japan.
Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Tokyo, Japan.
Anim Cogn. 2021 Nov;24(6):1179-1189. doi: 10.1007/s10071-021-01508-1. Epub 2021 Mar 29.
A face-to-face configuration and eye-to-eye contact are considered a basis for intersubjectivity, as they create a situation in which interactants are mutually attentive. Studies in humans have shown that the face-to-face configuration establishes active engagement by interactants in subsequent interactions, but it is not clear whether a similar function exists in non-human animals. Using data from a group of Japanese macaques (Macaca fuscata), this study compared dyadic play fighting sessions preceded and not preceded by a face-to-face configuration. During play fighting, players compete to gain an advantage over their playmates by attacking them unilaterally (i.e., attacking them without being attacked or pinning them to the ground). Defining the inter-player asymmetry of active engagement in play in terms of the difference in the duration of each individual's advantage over the other, we found that asymmetry was lower in play bouts with a face-to-face beginning than in play bouts without one. Additionally, in play bouts not preceded by a face-to-face configuration, individuals who faced their partner at the onset of play unilaterally attacked their partner for a significantly longer duration than did those who did not face their partner at the onset of play. Conversely, in play bouts preceded by a face-to-face configuration, there was no difference in the duration of unilateral attacks. Overall, our results indicated that the face-to-face configuration in Japanese macaques functions as a platform to establish mutual engagement by interactors and enhances symmetry within play interaction.
面对面的姿势和眼神接触被认为是主体间性的基础，因为它们创造了一种互动者相互关注的情境。人类研究表明，面对面的姿势建立了互动者在后续互动中的积极参与，但在非人类动物中是否存在类似的功能尚不清楚。本研究使用一组日本猕猴（Macaca fuscata）的数据，比较了面对面姿势前后的对偶玩耍战斗。在玩耍战斗中，玩家通过单方面攻击（即不被攻击或不将对方压在地上）来争夺对玩伴的优势。通过比较每个个体相对于另一个个体的优势持续时间的差异来定义玩耍中主动参与的玩家间不对称性，我们发现，面对面开始的玩耍战斗中不对称性低于没有面对面开始的玩耍战斗。此外，在没有面对面姿势的玩耍战斗中，与面对面开始玩耍的个体相比，那些在玩耍开始时没有面对其伴侣的个体进行单方面攻击的持续时间显著更长。相反，在面对面姿势开始的玩耍战斗中，单方面攻击的持续时间没有差异。总体而言，我们的结果表明，日本猕猴的面对面姿势作为一种平台，通过互动者建立了相互参与，并增强了玩耍互动中的对称性。
