Absence of self-recognition in a monkey (Macaca fascicularis) following prolonged exposure to a mirror.

To date only chimpanzees, orangutans, and humans have been found capable of recognizing themselves in mirrors. In an attempt to provide a more definitive test of the capacity for self-recognition in monkeys. I gave a preadolescent crab-eating macaque 2400 hr of mirror exposure. However, patterns of self-directed behavior never developed and a more explicit test of self-recognition yielded negative results. The data indicate possible differences between great apes and monkeys in self-awareness.