Self-recognition is an intrinsic part of the selfie. While the ability to recognize oneself is often taken for granted, just how unusual is it in other animals? Scientists have devised the mirror test in order to learn about how pervasive this ability is across the animal kingdom. In this test, researchers present a study subject with a mirror and evaluate their response towards their own reflection. In order to have self-recognition, subjects must be able to recognize themselves in the mirror. Self-recognition is identified by self-directed behaviors. For instance, by inspecting body parts that are otherwise obscured, such as the inside of one’s mouth. (We’ve all done that before!) Researchers also combine the mirror test with the mark test, where the subject is painted in an area that can only be seen in the mirror (e.g., behind the eye). If the individual inspects the marked part of their body while looking at their reflection, then they are likely performing that action because they understand that the mark is on their body.
As it turns out, mirror self-recognition is fairly rare. Aside from us, great apes (chimpanzees, bonobos, gorillas, orangutans), dolphins, and elephants demonstrate self-recognition. Go figure that we’d find it in the brainy mammals. While most of these studies are based on the reactions of captive mammals, researchers have recently brought the lab into the field in order to explore how wild animals respond to their reflections (see video clips below). Occasionally, we can see self-recognition in the wild without the aid of mirrors. For example, Jill Pruetz has observed a young infant chimpanzee gazing into her reflection in the Sakoto pool at Fongoli, Senegal (see the second video clip below). Finally, don’t be surprised if new research shows that more species also have this ability, as some critics have suggested that flaws in the mirror and mark tests are biased against species that tend to avoid direct eye contact during social interactions, or that display more subtle forms of self-directed behavior.
See what I mean in these videos.
Mirror test with Gabonese chimpanzees:
Watch an infant Fongoli chimp play with her reflection at Sakoto pool (very briefly at 1:08 or 46:55):