Populin, who studies the neural bases of perception and behavior, had implanted head implants in two rhesus macaque monkeys while preparing to study attention deficit disorder. Then Abigail Raja, an animal technician from the Neuroscience Training Program, mentioned that one of the animals could be recognized in a small mirror. “I told him that the scientific literature said he can’t do this,” says Populin, “so we decided to do a simple study.” To her satisfaction, the graduate student turned out to be right.
In thebrand standard test, a harmless mark is put on the animal’s face, which can only be seen in a mirror.If the looks of the animals in the mirror lead you to touch the mark, you are said to be self-aware: it is thus known that the mirror shows its own reflection, not that of another animal. Rhesus macaques, a mainstay of medical and psychological research, routinely failed the test.
But in Populin’s lab, the monkeys with the markings were staring at each other. Furthermore, while other macaques interpret the monkey they see reflected as an intruder and behave aggressively, these rhesus macaques devoted themselves to eexamine areas of your bodyespecially the genitalia, which had never been seen before, turning upside down in some cases. When the researchers covered the glass mirror with black plastic, these behaviors disappeared, and the monkeys ignored what had been the subject of fascination.
