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.^[1] 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,^[2] and being aware of their own bodies, while humans have abnormally good vision, and thus intelligence that is highly visual.

In the classic MSR test, an animal is anesthetized and then marked (e.g. paint or sticker) on an area of the body the animal normally cannot see (e.g. forehead). When the animal recovers from the anesthetic, it is given access to a mirror. If the animal then touches or investigates the mark on itself, it is taken as an indication that the animal perceives the reflected image as an image of itself, rather than of another animal.

Very few species have passed the MSR test. Species that have include the great apes, a single Asian elephant, manta rays, 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.^[3][4]