What Mirrors Tell Us About Animal Minds
… including our own.
By ED YONG
Feb 13 2017
A couple of weeks ago, an editor at The Guardian tweeted an image of a bald eagle staring at its reflection in a body of water. “This photo of an eagle taking a hard look at itself is not a metaphor for anything that’s been in the news recently,” he wrote.
At the time of this writing, the image has been retweeted 62,000 times.
And it prompted one of my colleagues at The Atlantic to ask: “Are eagles intelligent enough to recognize their own reflections?”
In March 1838, a young and little-known biologist named Charles Darwin asked the same question. On a visit to London Zoo, he stepped into a cage with an orangutan named Jenny, and marveled as she played with a mirror. He noted that she was “astonished beyond measure” at the glass. She examined it, kissed it, made faces at it, and contorted her body as she approached it. What did she see in the mirror? Did she recognize herself? And perhaps most importantly, how could you even tell?
Psychologist Gordon Gallup Jr. came up with a way, over a century later. In 1970, he got four captive chimps accustomed to a mirror, and anesthetized them. While they were out, he dabbed red dye on their eyebrows. When they came to and caught sight of their reflections, they did exactly what humans would do—they stared at their faces and touched their own eyebrows. Monkeys, by contrast, made no moves to examine their own red-marked faces. They couldn’t recognize themselves in the mirror, Gallup concluded. But chimps could.
“Recognition of one’s own reflection,” he wrote, “would seem to require a rather advanced form of intellect… Moreover, insofar as self-recognition of one’s mirror image implies a concept of self, these data would seem to qualify as the first experimental demonstration of a self-concept in a subhuman form.”
Gallup’s mirror test is one of the most famous and controversial techniques in the study of animal intelligence. It has been administered to dozens of species, in much the same way. If an animal inspects the mark on its body (and not on the reflection), and if it interacts with that area more often than usual, it passes the test. At the very least, that’s a sign of self-recognition. It suggests that the animal has a sense of self—a mental representation of its own body or appearance. Perhaps, as Gallup has repeatedly argued, it indicates self-awareness.
Some animal species perform inconsistently on the test. Chimps and orang-utans have unambiguously passed, but they don’t always. An Asian elephant named Happypassed in 2006 after staring into a really big mirror, and examining a mark on her head with her trunk—but two other elephants failed.
Killer whales and bottlenose dolphins have allegedly passed; they’re obviously less dextrous than apes or elephants, but they seemed to go to special lengths to inspect marked body parts by twisting, turning, and stretching. Two captive manta raysreportedly did something similar, but as with many of these studies, it’s hard to interpret the creatures’ behavior.