Capgras Syndrome: a disorder of kin recognition

Capgras Syndrome is a psychotic condition characterized by the delusion that someone has been replaced by an imposter. It is named after an early twentieth century French psychiatrist, Joseph Capgras, who himself referred to the condition as “l’illusion de sosies”, i.e. the illusion of doubles (Capgras and Reboul-Lachaux 1923). Although cases involving ‘doppelgänger’ doctors, household staff, neighbors, pets and inanimate belongings have all been reported, typically the targets of the delusion are close relatives of the subject (Ellis, Luauté and Retterstøl 1994, Wallis 1986). Some of the earliest attempts to explain the condition sought psychodynamic causes in the social and emotional tensions experienced by the subject in their formative years; by contrast, since the 1970s, there has been greater interest in identifying the physical basis of the disorder (Berson 1983, de Pauw 1994, Edelstyn and Oyebode 1999). A third of reported cases are accompanied by some form of cerebral damage (Ellis and de Pauw 1994, Signer 1987, 1994).