What does mirror self-recognition really mean?
We are all fascinated by the intellectual abilities of animals; with the blatant use of personification in
one could rightfully think that deep-down, we all wished our beloved creatures could do the things we see them accomplish in cartoons and storybooks. I’m no different; in fact, whenever I read Bob O’Hara ’s posts or comments, in my head, I imagine The Beast moving his lips and doing most of the talking. So it is easy to understand that when science actually does present us with some evidence that animals are indeed like us (at least cognitively), we get excited. Sometimes I wonder if our excitement goes a little far…
Mirror self-recognition (MSR) as a test for “knowing oneself” was introduced in 1970 by Gordon Gallup when he revealed that chimpanzees can recognize a colored spot placed on a part of their body, only visible with the help of a mirror, is in fact NOT on another animal, but on the monkey looking into the mirror. Many animals have been tested, but only 4 great apes, bottlenose dolphins and Asian elephants have passed this test. Besides humans, of course.
MSR is the gold standard test of self-identity in science and a new member has entered the club. In the most recent issue of PLoS Biology, researchers from Germany present evidence that magpies also recognize themselves in a mirror.
Essentially, the researchers placed a sticker on the black throat feathers of the birds, which caused them to subsequently scratch at the mark until it was gone. This did not happen in the absence of a mirror. Nor did it occur if a black mark was placed on the black feathers (the best “sham” mark used in a MSR test to date, by far.) Thus, there was no choice but to conclude that since the corvids only scratched the non-visible mark with the assistance of the mirror, they in fact understood that they were looking at themselves.
We knew that magpies (and their close cousins, scrub jays, crows, etc…) are smart, with many an outdoorsman providing an anecdote describing how one of these birds successfully opened a zipped pack or saddlebag. But these data shed some new light on the avian world in general, with one of its members possessing the recognition skills of primates.
However, let’s take a closer look at the raw data. Only one of the birds (“Gerti”) was a real pro. Another (“Goldie”) had a decent showing in one trial, but the performance of the other subjects didn’t even come close. So in chimpanzees, while 75% of adult individuals exhibit MSR (ref), we now have 1 (maybe 2) magpies doing this. This is hardly the basis for a broad general conclusion that a corvid species exhibits a sense of self.
For me, the best that we can say about any of this is that there are individual animals out there that seem to be special. Koko the gorilla immediately comes to mind. As does this brilliant beast:
These animals should fascinate us because they are special. But why are so many not that interested in what makes those particular few so special. Why did Gertie the magpie exhibit a strong sense of self while Harvey wouldn’t even enter the compartment with the mirror? Using the surprising gifts of a select few animals to create generalizations about a species’ intelligence seems a bit cavalier to me.
So while I am fascinated with Gertie’s gifts, and excited that it was reproducibly reported, I think that I’ll hold off on bringing the corvids into the pavilion of consciousness just yet.
Prior, H., Schwarz, A., & Güntürkün, O. (2008). Mirror-Induced Behavior in the Magpie (Pica pica): Evidence of Self-Recognition PLoS Biology, 6 (8) DOI: 10.1371/journal.pbio.0060202