Recognizing that the individual appearing in the mirror in front of you is actually you is considered to be a sign of self-
awareness (known as “Mirror self-recognition” or MSR). Scientists can investigate this behavior by using a “mark test.” A colored (visible) or colorless (invisible) mark is placed on the face – somewhere that can only be seen by the animal looking at a reflection in a mirror. Then, they watch to see if the subject pays more attention (touching or scratching) to the part of the body with the visible mark than it does to the part with the invisible mark. If it does, this suggests the animal recognizes its reflection.