We've looked at a few different delusional misidentification syndromes so far and sent the doppelgangers packing. But what if the mysterious stranger in your life happens to be that weirdo in the mirror?
You've probably seen this played out for laughs in everything from the Marx Brothers' "Duck Soup" to "Shaun the Sheep." Your reflection just doesn't look or move quite right, so you move around till the impostor gives him or herself away. Assuming the rest of your life doesn't resemble a slapstick farce, however, it's probably best to seek professional help.
In clinical psychology, this is known as mirrored self-misidentification. A 2001 study from Macquarie Centre for Cognitive Science (MCCS) looked at two dementia patients. The two individuals could no longer recognize their own faces in the mirror, but they had no problem recognizing the faces of others in reflections. Both individuals suffered from right-side brain lesions, the portion of the brain associated with self-facial recognition and even the use of self-describing adjectives.
But dementia isn't the only way to experience mirrored self-misidentification. A 2008 MCCS study gave 12 highly hypnotizable people the hypnotic suggestion that the face in the mirror was a stranger. The majority of the subjects ended up describing their reflections as having different facial features than their own.
So there you have it! If you can't throw your false reflection off with sudden, unpredictable movements, consult a doctor or the family hypnotist.