spiegelproef

The spiegelproef, or mirror test, is a behavioral experiment designed to assess self-recognition and self-awareness in animals by observing reactions to their own reflection. The test was proposed by psychologist Gordon Gallup Jr. in 1970 and has since become a standard tool in comparative cognition.

In a typical procedure, an animal is observed in front of a mirror to establish its normal responses. A non-toxic, odorless mark is then placed on a part of the animal’s body that it cannot see without a mirror, such as the face or ear. The animal is given access to the mirror again, and researchers monitor whether the animal notices and investigates the mark on its own body, or uses the mirror to inspect the mark. The appearance of self-directed behavior is taken as evidence of mirror self-recognition.

Findings have varied. Several great apes, notably chimpanzees and orangutans, have shown self-recognition in many studies. Dolphins and elephants have yielded mixed results, and some bird species, such as magpies, have produced positive outcomes under certain conditions. Many other species fail to pass the test, though researchers caution that failure may reflect sensory or ecological differences rather than absence of self-awareness.

The spiegelproef is subject to methodological criticisms. Critics argue that the test assumes vision is the primary modality for self-recognition, neglects olfactory or tactile cues, and that passing the test does not prove full self-awareness. Nonetheless, it remains a widely used tool and has spurred developments in alternative methods for assessing consciousness and social cognition in non-human animals.