Self-awareness has long been described as a capacity unique to, or perhaps defining, humans (Gallup, 1977b, 1983; Suarez & Gallup, 1981), and has been evaluated in numerous nonhuman species since the innovative studies of Gallup (1970). The ontogeny of self-recognition in human infants, that is, the acquisition of knowledge of one's physical appearance as a component of self-awareness, has also been explored by those with interests in human development, with most studies employing a variant of the Gallup (1970) mark test (Amsterdam, 1972; Bertenthal & Fischer, 1978; Brooks-Gunn & Lewis, 1984; Dixon, 1957; Papoušek & Papoušek, 1974). This test entails a surreptitiously applied mark (rouge placed on the child's nose) and attentional orientation to the mark as the dependent variable as the child views itself in a mirror. Similarly, self-recognition has been evaluated, principally through the use of the mark test, with a number of nonhuman primate species and elephants (see review by Anderson, 1984; Calhoun & Thompson, 1988; Gallup, 1970, 1977a,b, 1983, 1991, SAAH3; Gallup, Wallnau, & Suarez, 1980; Ledbetter & Basen, 1982; Lin, Bard, & Anderson, 1992; Povinelli, 1989; Robert, 1986; Suarez & Gallup, 1981; Swartz & Evans, 1991). Self-recognition, as one facet of self-awareness, has been demonstrated through the mirror mark test in chimpanzees (Gallup, 1970; Lin, Bard, & Anderson, 1992; Suarez & Gallup, 1981), and orangutans (Lethmate & Dücker, 1973), and the gorilla Koko (Patterson & Cohn, SAAH17).