Gallup, G. G. (1977). Self recognition in primates: A comparative approach to the bidirectional properties of consciousness. American Psychologist, 32(5), 329-338.
http://dx.doi.org/10.1037/0003-066X.32.5.329
Describes a technique in which organisms are provided with extended exposure to mirrors and then given an explicit test of self-recognition (through the unobtrusive application of marks to facial features visually inaccessible without a mirror). Use of this procedure with chimpanzees and orangutans in a series of studies by the present author provided evidence of self-recognition, with patterns of self-directed behavior emerging after only 2–3 days. In support of the widely held view that the self-concept may develop out of social interaction with others, the capacity for self-recognition in chimpanzees appears to be influenced by early social experience. To date, however, attempts to demonstrate self-recognition in all other species except man have failed. The phyletic limits of this capacity may have important implications for claims concerning the evolutionary continuity of mental experience. (64 ref) (PsycINFO Database Record (c) 2016 APA, all rights reserved)