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. to determine whether an animal possesses the ability of visual self-recognition.^[1] In this 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 it subsequently touches or examines the mark on its own body, this behavior is interpreted as evidence that the animal recognizes its reflection as an image of itself, rather than another animal.

The MSR test has become a standard approach for evaluating physiological and cognitive self-awareness. Few species have passed this test. However, several critiques have been raised that challenge the test's validity.^[2][3] Some studies have questioned Gallup's findings;^[2] others have discovered that animals exhibit self-awareness in ways not captured by the test, such as differentiating between their own songs and scents and those of others.^[4]