What does an animal see in a mirror? Until 1970, the accepted answer was "another animal": a stranger to be greeted, threatened, courted--or ignored. In that year, psychologist Gordon Gallup Jr. came up with the idea of giving a chimpanzee a mirror and painting a mark on his face while he slept. With one small gesture--reaching to touch the mark on his own face when he awakened--the chimp touched off a revolution not only in psychology, but philosophy as well. He saw himself.
It was a minor revolution at first, because only chimps and other closely related primates passed the "mirror test." Then, in 2001, Diana Reiss of the New York Aquarium showed that bottlenose dolphins marked with dye recognized their reflections. Last week, Reiss, Joshua Plotkin and Frans de Waal of Emory University announced that Happy, a 34-year-old Asian elephant at the Bronx Zoo, had shown the same ability. (Two other elephants who live there also took the mirror test; they flunked.) "The mirror test asks something quite hard," says Patricia Churchland, a professor of philosophy at the University of California at San Diego. "The animal has to say, 'I'm here, that is a perfect replica of me, but it isn't me'." The experiment appears to measure something more, or different, than what we usually mean by "animal intelligence," which we tend to define in practical terms. Animals are "smart" if they can communicate or use tools to get food. But recognizing one's reflection has no obvious survival value; it's a kind of intellectual luxury that until recently only human beings were believed to enjoy.
In fact, this ability might not even be confined to mammals. Many researchers think the next breakthrough in animal intelligence will be among smart, social birds such as crows, ravens and parrots. African gray parrots may be among the smartest animals on earth. Irene Pepperberg of Brandeis University has been training one for nearly three decades and reporting her results in peer-reviewed journals. According to Pepperberg, Alex has a vocabulary of 50 to 100 words that he combines spontaneously to answer questions or make requests; he names colors and shapes, counts objects up to at least five and can do simple addition. Confronted with a tray of scattered blocks and balls of different colors, he can answer a question like "How many green blocks?" After that he usually asks for a nut, but often lets the nut drop; he seems to perform to please his trainers. Or perhaps to annoy them. When he wants to go back to his cage, Pepperberg says, he will sometimes give every possible answer to a question except the right one.
Intuitively, Alex seems to possess self-awareness, but he's never had the mirror test. He can't, because a student once took him with her to the restroom, and when Alex saw himself in the mirror, he squawked "What's that?" "It's you," the student replied, fatally contaminating any possible future results from the test. Pepperberg did try the mirror test on another of her parrots, but the results were "equivocal," she says; he scratched at a red mark for nine seconds, couldn't get it to go away, and then ignored it. In the wild, she notes, parrots are frequently covered with glop from their meals, so it's possible they're just not programmed to care about a spot on their faces.
That speaks to the practical difficulties in animal research, but also a conceptual one, says Colin Allen, a professor of philosophy at Indiana University. He sees a danger that the mirror experiment could become a kind of pass/fail exam for species. Self-awareness, he says, "is not a simple trait; animals will have it in various degrees and different kinds, not all lined up in a single continuum."
So the simple answer is, we don't know what an animal sees in the mirror. Not even Alex, wonderful as he is, has words for "think" and "feel." But dolphins, elephants and human beings all have large brains, a complex social structure and a capacity for altruism toward members of the same social group. Is it just a coincidence that they pass the mirror test? Or does empathy, which implies an awareness of the state of other individuals, depend on a measure of self-consciousness? "This research," says Reiss, "links us to the rest of the natural world. It shows there are other minds around us." Think about that the next time you look in the mirror.