Chimpanzees recognize themselves in mirrors

Heyes’ (1994, Anim. Behav., 97, 909–919; 1995, Anim. Behav., 50, 1533–1542) recent account of chimpanzees’, Pan troglodytes, reactions to mirrors challenged the view that they are capable of recognizing the equivalence between their mirror images and their physical appearance. In particular, she argued that observations that chimpanzees touch surreptitiously placed marks on their faces while in front of mirrors can be explained as an interaction between ambient levels of face touching and procedural artefacts of the anaesthetization and markings of the subjects. Using new analytical techniques, data are reported that falsify the central predictions generated by her account and confirm predictions derived from the self-recognition model.