Data from: Chimpanzees recognize their own delayed self-image

Unlike mirror self-recognition, recognizing one's own image in delayed video footage may indicate the presence of a concept of self that extends across time and space. While humans typically show this ability around 4 years of age, it is unknown whether this capacity is found in non-human animals. In this study, chimpanzees performed a modified version of the mark test to investigate whether chimpanzees could remove stickers placed on the face and head while watching live and delayed video images. The results showed that three of five chimpanzees consistently removed the mark in delayed-viewing conditions, while they removed the stickers much less frequently in control video conditions which lacked a link to their current state. These findings suggest that chimpanzees, like human children at the age of 4 years and more, can comprehend temporal dissociation in their concept of self.与镜像自我识别（mirror self-recognition）不同，在延时视频画面中识别自身影像，或许可以证明个体拥有跨越时空的自我概念。尽管人类通常在4岁左右便具备该项能力，但目前尚不清楚非人类动物是否拥有此能力。本研究采用改良版标记测试（mark test），以检验黑猩猩在观看实时与延时视频画面时，能否移除贴在面部和头部的贴纸。实验结果显示，5只黑猩猩中有3只在延时观看条件下会持续稳定地移除标记，而在与自身当前状态无关联的对照视频条件下，它们移除贴纸的频率则显著更低。上述研究结果表明，黑猩猩与4岁及以上的人类儿童一样，能够理解自我概念中的时间解离现象。