The hamadryas baboon is one primate species that fails the mirror test.
The mirror test—sometimes called the mark test, mirror self-recognition (MSR) test, red spot technique, or rouge test—is a behavioral technique developed in 1970 by American psychologist Gordon Gallup Jr. as an attempt to determine whether an animal possesses the ability of visual self-recognition. The MSR test is the traditional method for attempting to measure physiological and cognitive self-awareness. However, agreement has been reached that animals can be self-aware in ways not measured by the mirror test, such as distinguishing between their own and others’ songs and scents.
In the classic MSR test, an animal is anesthetized and then marked (e.g., painted or a sticker attached) on an area of the body the animal cannot normally see. When the animal recovers from the anesthetic, it is given access to a mirror. If the animal then touches or investigates the mark, it is taken as an indication that the animal perceives the reflected image as an image of itself, rather than of another animal.(see Face perception)
Very few species have passed the MSR test. Species that have, include the great apes (including humans), a single Asiatic elephant, dolphins, orcas, the Eurasian magpie, and the cleaner wrasse. A wide range of species has been reported to fail the test, including several species of monkeys, giant pandas, and sea lions.
Animals that are considered to be able to recognize themselves in a mirror typically progress through four stages of behavior when facing a mirror:
- social responses
- physical inspection (e.g. looking behind the mirror)
- repetitive mirror-testing behavior
- realization of seeing themselves
European magpies have demonstrated mirror self recognition.
Since the 1970s psychologists have used mirrors to search for signs of self-awareness in both humans and animals. Along the way, they came to believe that humans were almost universally able to pass a mirror-based self-recognition test by 24 months of age. But a 2004 study published in Child Development called that idea into question. Researchers found the widely accepted finding only applied to kids from Western nations, where most of the previous studies had been done. Now, a study published September 9 in The Journal of Cross-Cultural Psychology is reinforcing that idea and taking it further. Not only do non-Western kids fail to pass the mirror self-recognition test by 24 months—in some countries, they still are not succeeding at six years old.
What does it mean? Are kids in places like Fiji and Kenya really unable to figure out a mirror? Do these children lack the ability to psychologically separate themselves from other humans? Not likely. Instead researchers say these results point to long-standing debates about what counts as mirror self-recognition, and how results of the test ought to be interpreted.
Based on results with Western children, psychologists have linked the age humans start passing the mark test with other milestones that happen around the same time, such as development of empathy. The ability to separate oneself from others is often thought of as a prerequisite for understanding that someone else might be hurt or sad, even if the beholder is not.
Nursery children of non-western parents are inferior at speaking Danish, have an inferior mathematical understanding and have inferior social skills than children of Danish parents, the study of 13,000 children in Denmark shows.