The Mirror Test
Behavior is the mirror in which everyone shows their image. ~ German writer Johann Wolfgang von Goethe
We look upon the intelligence of others with bias. This is true of other humans and even more so of non-human animals.
Religious bias long precluded serious consideration that other life could possibly be smart. Plants, microbes, and “primitive” creatures merited no investigation for intelligence. Ignorant human presumption long foreclosed intelligent inquiry – rich irony indeed.
A few birds, particularly corvids, were considered an exception. But then, the cleverness of crows has been apparent since ancient times.
As with corvids, the striking smarts of rats rendered rodents acceptable subjects of intelligence research. Their easily being caged helped.
Mammals have dominated zoological study of intelligence, especially those most like us. Darwin held a mirror up to an orangutan at a zoo and recorded the animal’s reaction. Darwin did not know what to make of the orangutan’s responses; nor did the orangutan know what to make of Darwin and his unnatural object. Hairless apes are mighty peculiar.
In the late 1960s, American psychologist Gordon Gallup, Jr., working with chimpanzees, followed in Darwin’s footsteps. Others followed.
The mirror test consists of putting a mirror in front of an animal and recording its response behavior. The mirror test often involves painting a dot on the test subject’s body, as opposed to other animals that may appear in the mirror. The surmise is that, by indicating its marked dot during a mirror test, an animal recognizes itself. Having repeatedly been exposed to mirrors, most toddlers recognize themselves in the mirror around 2 years of age; before then, they cannot.
The mirror test acts a presumed proxy for self-awareness. But mirrors don’t appear in the wild, so the supposition behind the mirror test as meaningful is silly.
Cleaner wrasse are a tiny, territorial, tropical fish with excellent eyesight. They make their living by cleaning parasites off bigger fish. Mark a spot on them and put a mirror in front of them, and a wrasse knows right away that something is amiss. How wrasse know what they naturally look like is a mystery (the inherent enigma of the mirror test).
Trained pigeons pass the mirror test but not untrained ones. So too monkeys. Wild creatures’ lack of exposure to mirrors is the difference. With familiarity comes comprehension. People score higher IQs when they are familiar with the test.
Monkeys are superior to men in this: when a monkey looks into a mirror, he sees a monkey. ~ Mauritian writer Malcolm de Chazal
Animals known to recognize themselves in the mirror include magpies, elephants, dolphins, and apes. Many different monkeys were given the mirror test over the years. Only a tiny South American monkey – the cotton-top tamarin – passed. Researchers dyed tamarins’ white topknot in brilliant psychedelic colors, a change no self-respecting tamarin could fail to notice.
Mirror test results can be ambiguous, depending upon the intelligence of the observer, not the participant. Presented with a mirror, pigs don’t care what they look like. But swine are quite willing to use the information from a mirror to find food, which is of considerable interest.
In the end, experiments that test animals’ cognition by determining when they succeed and when they fail may reveal more about human minds than other species. ~ American life-sciences writer Susan Milius