Mirror self-recognition

Mirror self-recognition describes a psychological test used to make inferences about the presence or development of self-recognition in children, patients or non-human animals.

In this test, the subject is marked with on parts of its body normally invisible to it and placed in front of a mirror. If it recognizes the mark it sees in the mirror as actually being located on its body, it must possess some representation of the concept of self. Usually, the test counts as passed if the subject scratches the mark away from its body but other variants exist (e.g. using videos). Self-recognition is considered an important aspect of theory of mind, the capacity to take the perspective of another organism in order to anticipate its behaviour.

Traditionally, both theory of mind and the passing of the mirror test have been considered uniquely human but since the last third of the 20th century, evidence has accumulated that contradicts this view. So far, mirror self-recognition has been reported for chimpanzees, orangutans, bonobos, dolphins, elephants and magpies.

In children, the capacity develops around the middle of the second year of life, around the same time as the use of personal pronouns.