http://www.pnas.org/content/98/10/5937.long
The ability to recognize oneself in a mirror is an exceedingly rare capacity in the animal kingdom. To date, only humans and great apes have shown convincing evidence of mirror self-recognition. Two dolphins were exposed to reflective surfaces, and both demonstrated responses consistent with the use of the mirror to investigate marked parts of the body. This ability to use a mirror to inspect parts of the body is a striking example of evolutionary convergence with great apes and humans.
http://ac360.blogs.cnn.com/2010/11/15/a ... he-mirror/The capacity for mirror self-recognition (MSR) has been found only in humans and great apes (1–8). In humans, MSR does not emerge reliably until 18–24 months of age (9) and marks the beginning of a developmental process of achieving increasingly abstract psychological levels of self-awareness, including introspection and mental state attribution (10, 11). The first evidence for MSR in a nonhuman species was experimentally demonstrated in the common chimpanzee (1), but numerous subsequent attempts showed no convincing evidence of self-recognition in a variety of other primates and nonprimates, including monkeys, lesser apes, and elephants (12–18). All of these species, including African gray parrots (19) demonstrate the ability to use a mirror to mediate or guide their behavior. A provocative debate continues to rage about whether self-recognition in great apes implies that they are also capable of more abstract levels of self-awareness (20). Therefore, research on self-recognition in other species will have profound implications for the idea that humans are the only species to conceive of their own identity.
