Supplementary Data Table 1 - Data and demographics Study 1 from Visually attending to a video together facilitates great ape social closeness

Humans create social closeness with one another through a variety of shared social activities in which they align their emotions or mental states towards an external stimulus such as dancing to music together, playing board games together or even engaging in minimal shared experiences such as watching a movie together. Although these specific behaviours would seem to be uniquely human, it is unclear whether the underlying psychology is unique to the species, or if other species might possess some form of this psychological mechanism as well. Here we show that great apes who have visually attended to a video together with a human (Study 1) and a conspecific (Study 2) subsequently approach that individual faster or spend more time in their proximity than when they had attended to something different. Our results suggest that one of the most basic mechanisms of human social bonding—feeling closer to those with whom we act or attend together—is present in both humans and great apes and thus has deeper evolutionary roots than previously suspected.

人类通过各类共享社交活动构建彼此间的社会亲密度，在这些活动中个体将情绪或心理状态指向同一外部刺激源，例如一同随乐起舞、共同参与桌游，或是诸如一同观影这类极简的共享体验。尽管这类具体行为看似是人类独有的特质，但目前尚不明确其背后的心理机制是否仅为人类独有，亦或是其他物种也具备该类心理机制的某种形式。本研究表明，与人类一同观看视频（研究1）以及与同类一同观看视频（研究2）的类人猿，后续相较于观看不同内容时，会更快趋近该个体，或在该个体附近停留更久。本研究结果显示，人类社会联结最基础的机制之一——与一同行动或共享注意力的对象产生亲近感——在人类与类人猿中均存在，因此其演化根源比此前推测的更为深远。