Although various forms of self-knowledge and self-awareness are thought to be present in human infants (Neisser, 1988; Stern, 1985), the question of selfawareness in nonhuman primates has been overshadowed by discussion of their capacity for mirror self-recognition (Gallup, 1977a, 1985; Suarez & Gallup, 1981). Evidence for mirror self-recognition (MSR) via passing the mark test and/or examining body parts not visible without a mirror have been obtained for each great ape species (Gallup, 1970; Hyatt & Hopkins, SAAH15; Miles, SAAH16; Patterson & Cohn, SAAH17; Suarez & Gallup, 1981). In contrast, evidence for MSR in monkeys is much more questionable (Anderson, SAAH21; Gallup, SAAH3): Self-examination using the mirror is typically absent, and mark-directed behaviors during the mark test are infrequent and different in form than that seem in the apes (e.g., Itakura, 1987; Thompson & Boatright-Horowitz, SAAH22).
The rationale for using the mark test in the assessment of self-recognition is that the individual must have a mental representation of the self that he or she understands to be reflected in the mirror (Gallup, 1988). The presence of the mark is a violation of that internal representation, and therefore is a novelty to which the individual's behavior is directed.
Macaques may have failed to provide evidence for MSR for reasons other than a failure to have an internal representation of the self. First, few subjects have been used in the tests of self-recognition, ranging from one (Gallup, 1977a) to four (Gallup, 1970) of any particular species.