Can Rhesus Macaques Pass The Mirror Test?

Some 40 or more years ago, American psychologist Gordon Gallup came up with a mirror test for self-awareness that could be applied across a whole range of species. In the classic versions of the experiment, primates, say, were anaethetised before a small dab of red dye was placed on their forehead. Measurements were then taken, on recovery, to compare their behaviour with their reflections in a mirror. A greater incidence of movements of hands to forehead to investigate the area around the spot suggested to researchers that the animals concerned had some concept of self-awareness - "Look that's me!" Higher primates like chimps could pass the test, as has one elephant to date. But, so far, no monkeys have ever demonstrated they can pass the mirror test. If the test really did test for self-awareness, any animal which passed it would have dissolved one major cognitive barrier between humans and the rest of the animal kingdom, however, the test has always been criticized because not all researchers are convinced that body awareness is the same as self-awareness. That there is a difference between examination of one's body and a deeper sense of knowledge of oneself as a psychological entity with inner mental states. This "The Scientist" piece comments on some recent work reported in PLoS 1 where rhesus monkeys are held to have passed the mirror test for the first time. Instead of having red blobs of paint on their heads, these monkeys had already been implanted with electronic terminals for experimentation. Would they react to the sight of the terminals in a mirror? Although they did indeed react as if to satisfy the test, the experiment has drawn criticism, including some from the originator of the original test - Gordon Gallup. Gallup says this experiment is un-interpretable because the monkeys could feel the implant as well as see it - whereas , in his test, this was controlled for because the only way the monkeys could be aware of the paint mark was by seeing it. SO, for the time being, for several reasons the question of whether or not monkeys have any self-awareness remains open.

Since PLoS is a free journal here is the url for the original paper - in case anyone wants to follow it up.

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0012865