Self-awareness in the gorilla Koko (1991)

Patterson, F.

Abstract

Responses of an adult female gorilla (Koko) to her own mirror reflections are described, documented and analyzed. During every session, Koko frequently exhibited self-directed behaviors such as grooming her underarms and picking at her teeth with the aid of the mirror ... or using the mirror to inspect a spot on her cheek. ... The evidence provided by the mirror study combined with that provided by Koko's linguistic abilities leaves little doubt that she is capable of self-recognition and is self-aware.