This paper reports further observations, experiments, and methodological considerations concerning mirror-mediated self-recognition and mirrorcorrelated behavior in pigtailed monkeys (Macaca nemestrina) and chimpanzees (Pan troglodytes). We also describe from videotape an instance of apparent self-recognition by a monkey. Last, we discuss behavioral processes we think applicable to the “passing” of the Gallup mark test and to the larger issues of self-awareness and a self-concept.

The empirical facts of mirror-mediated/mark-directed (MM/MD) responding in some chimpanzees and orangutans, but not in gorillas nor in the dozen or more monkey species tested by the well-known Gallup (1970) procedure (hereafter, the “mark test”), have been widely discussed (e.g., Anderson, 1984; Gallup, 1987). A positive mark test is said to imply – even to operationally define – self-recognition, self-awareness, a self-concept, and, ipso facto, consciousness. From there, questions of proximate causes, function, development, and evolution are pursued; species discontinuities are postulated; comparisons with human cognition are made, and searches are prompted for indications of empathy, deception, attributions of mental states, and more. If sentience or self-awareness is attributed to any nonhuman animals, ethical and legal questions of human obligations toward animals are made even more urgent. In short, the importance of this range of issues should find us disquieted that experimental investigations of self-recognition in primates have relied so strongly on tests with mirrors (see discussion by Cheney & Seyfarth, 1990; commentary by Povinelli & deBlois, 1992).