Fregoli delusion is the mistaken belief that some person currently present in the deluded person’s environment (typically a stranger) is a familiar person in disguise. The stranger is believed to be psychologically identical to this known person (who is not present) even though the deluded person perceives the physical appearance of the stranger as being different from the known person’s typical appearance. To gain a deeper understanding of this contradictory error in the normal system for tracking and identifying known persons, we conducted a detailed survey of all the Fregoli cases reported in the literature since the seminal Courbon and Fail (1927) paper. Our preliminary reading of these cases revealed a notable lack of definitional clarity. So, we first formulated a classification scheme of different person misidentification delusions so as to identify those cases that qualified as instances of Fregoli according to the above characterization: the mistaken belief that a known person is present in the environment in a different guise to his or her typical appearance. We identified 38 clear cases of this type and set out to answer a series of questions motivated by current hypotheses about the origin of the Fregoli delusion. We asked whether the patients misidentified particular strangers, made reference to the misidentified known persons using wigs or plastic surgery (or other techniques to disguise their appearance), misidentified many different strangers or only one, showed other symptoms (in particular, other misidentification delusions), and made inferences about the motives of the known persons in disguise. We conclude by discussing the implications of our findings for current hypotheses concerning the origin of the Fregoli delusion.
Humans have evolved different capacities to help navigate their social world: distinguishing between the agents and the objects in their environment, identifying conscious agents, recognizing conspecifics, identifying particular known persons, and tracking their persistence across time. Any of these capacities might be disrupted temporarily, causing, for example, transient failures to recognize a familiar person as he or she walks by in the street—something we all do from time to time. Brain damage or psychiatric illness might cause a more enduring, even permanent, disruption to any one, or combination, of these capacities. Studying these more enduring cases offers a unique opportunity to learn more about errors of agent tracking and identification, and thereby to better understand the normal systems for agent tracking. Our aim in this paper was to adopt this approach to advance understanding of the normal processes for person identification and tracking by reviewing the literature on a particular type of clinical error of person identification: the Fregoli delusion.
2 The Fregoli delusion
In 1927, Courbon and Fail described a case of delusion, in which a young Parisian woman believed that two Parisian actresses of the time (Sarah Bernhardt and Robine) pursued her closely. The two actresses were unrecognizable because they were “taking the form of people she knows or meets” (Ellis, Whitley, & Luauté, 1994, p. 134), including the strangers she saw in the street, doctors, friends, and previous employers. Courbon and Fail named this syndrome after the Italian actor and mimic Leopoldo Fregoli because of his extraordinary ability to impersonate people on stage. de Pauw, Szulecka, and Poltock (1987) described a similar case, an elderly lady who believed that her male cousin and his lady friend were disguising themselves with wigs and other methods and following her around.
These two cases involve the delusional misidentification of familiar persons disguised as others. The others in the environment (a stranger, an acquaintance, or a hospital staff member, for example) are perceived correctly as being physically unrecognizable strangers or relatively unfamiliar casual acquaintances—and yet are incorrectly identified as a different known person. For example, Courbon and Fail’s patient believed that the Sarah Bernhardt whom she saw on the stage on some Sunday night was the very same person that she saw on the street (in the disguise of a stranger) on the following Monday.
In these cases, there is some distinctive error(s) in the normal cognitive system for identifying and tracking known persons from the perception of their physical form. These cases are thus very unlike those other, more generic, persecutory, and referential delusions that are common in schizophrenia, and which involve delusional beliefs about being monitored by generic others, such as the Central Intelligence Agency (CIA). The others in these latter cases are personally anonymous—some personally unknown group entity rather than a specific known person, as occurs in Fregoli (see, e.g., Langdon, McKay, & Coltheart, 2008, for further discussion of persecutory delusions).
- Breen, N., Caine, D., & Coltheart, M. (2000). Models of face recognition and delusional misidentification: A critical review. Cognitive Neuropsychology, 17( 1), 55– 71.Crossref CAS PubMed Web of Science®Google Scholar
- Breen, N., Caine, D., & Coltheart, M. (2001). Delusional misidentification: Two cases of focal onset dementia. Neurocase, 7, 239– 254.Crossref CAS PubMed Web of Science®Google Scholar
- Breen, N., Caine, D., Coltheart, M., Hendy, J., & Roberts, C. (2000). Towards an understanding of delusions of misidentification: Four case studies. Mind & Language, 15( 1), 74– 110.Wiley Online Library Web of Science®Google Scholar
- Bruce, V., & Young, A. (1986). Understanding face recognition. British Journal of Psychology, 77( 3), 305– 327.Wiley Online Library PubMed Web of Science®Google Scholar
- Capgras, J., & Reboul‐Lachaux, J. (1923). L’illusion des “sosies” dans un delire systematisé. Bulletin de la Société de Médecine Mentale, 11, 6– 16. Translated by Ellis, H. D., Whitley, J., & Luauté, J‐P. History of Psychiatry, 1994, 5, 134–137.Google Scholar
- Christodoulou, G. (1978). Syndrome of subjective doubles. American Journal of Psychiatry, 135( 2), 249– 251.Crossref CAS PubMed Web of Science®Google Scholar
- Courbon, P., & Fail, G. (1927). Syndrome d’ “Ilusion de Frégoli” et schizophrénie. Bulletin de la Société Clinique de Médecine Mentale. Translated by Ellis, H. D., Whitley, J., & Luauté, J.‐P. History of Psychiatry, 1994, 5, 134–137.Google Scholar
- Courbon, P., & Tusques, J. (1932). Illusion d’intermétamorphose et de charme. Annales Médico‐ Psychologiques, 90, 401– 405.Translated by Ellis, H. D., Whitley, J., & Luauté, J.‐P. History of Psychiatry, 1994, 5, 134–137.Google Scholar
- Duggal, H. S. (2004). Interictal psychosis presenting with Fregoli syndrome. Journal of Neuropsychiatry & Clinical Neurosciences, 16( 4), 543– 544.Crossref PubMed Web of Science®Google Scholar
- Ellis, H. D., & Lewis, M. B. (2001). Capgras delusion: A window on face recognition. Trends in Cognitive Sciences, 5( 4), 149– 156.Crossref PubMed Web of Science®Google Scholar
- Ellis, H. D., & Young, A. W. (1990). Accounting for delusional misidentifications. British Journal of Psychiatry, 157, 239– 248.Crossref CAS PubMed Web of Science®Google Scholar
- Hirstein, W. (2005). Brain fiction: Self‐deception and the riddle of confabulation. Cambridge, MA: MIT Press.Google Scholar
- Hirstein, W., & Ramachandran, V. S. (1997). Capgras syndrome: A novel probe for understanding the neural representation of the identity and familiarity of persons. Proceedings of the Royal Society B, 264, 437– 444.Crossref CAS PubMed Web of Science®Google Scholar
- Langdon, R. (2011). Delusions and faces. In A. Calder, G. Rhodes, M. Johnson & J. Haxby (Eds.), The Oxford handbook of face perception (pp. 877– 892). Oxford, England: Oxford University Press.Google Scholar
- Langdon, R., & Coltheart, M. (2000). The cognitive neuropsychology of delusions. Mind & Language, 15( 1), 184– 218.Wiley Online Library Web of Science®Google Scholar
- Langdon, R., McKay, R., & Coltheart, M. (2008). The cognitive neuropsychological understanding of persecutory delusions. In D. Freeman, R. Bentall, & P. Garety (Eds.), Persecutory delusions: Assessment, theory and treatment (pp. 223– 238). Oxford, England: Oxford University Press.Google Scholar
- Lykouras, L., Typaldou, M., Gournellis, R., Vaslamatzis, G., & Christodoulou, G. N. (2002). Coexistence of Capgras and e syndromes in a single patient. Clinical, neuroimaging and neuropsychological findings. European Psychiatry, 17, 234– 235.Crossref CAS PubMed Web of Science®Google Scholar
- Margariti, M. M., & Kontaxakis, V. P. (2006). Approaching delusional misidentification syndromes as a disorder of the sense of uniqueness. Psychopathology, 39( 6), 261– 268.Crossref PubMed Web of Science®Google Scholar
- McEvedy, C. J., Hendry, J., & Barnes, T. R. (1996). Delusional misidentification: The illusion of Fregoli and a dog. Psychopathology, 29( 4), 215– 217.Crossref CAS PubMed Web of Science®Google Scholar
- Moriyama, Y., Muramatsu, T., Kato, M., Mimura, M., Akiyama, T., & Kashima, H. (2007). Fregoli syndrome accompanied with prosopagnosia in a woman with a 40‐year history of schizophrenia. Keio Journal of Medicine, 56( 4), 130– 134.Crossref PubMed Google Scholar
- Mulholland, C., & O’Hara, A. G. (1999). An unusual case of delusional misidentification: “Delusional hermaphroditism.” Psychopathology, 32( 4), 220– 224.Crossref CAS PubMed Web of Science®Google Scholar
- Papageorgiou, C., Lykouras, L., Ventouras, E., Uzunoglu, N., & Christodoulou, G. N. (2002). Abnormal P300 in a case of delusional misidentification with coinciding Capgras and Fregoli symptoms. Progress in Neuro‐Psychopharmacology & Biological Psychiatry, 26( 4), 805– 810.Crossref PubMed Web of Science®Google Scholar
- de Pauw, K. W., Szulecka, T., & Poltock, T. L. (1987). Fregoli syndrome after cerebral infarction. Journal of Nervous & Mental Disease, 175( 7), 433– 438.Crossref Web of Science®Google Scholar
- Phillips, M., & Sierra, M. (2003). Depersonalization disorder: A functional neuroanatomical perspective. Stress, 6( 3), 157– 165.Crossref PubMed Web of Science®Google Scholar
- Ramachandran, V. S., & Blakeslee, S. (1998). Phantoms in the brain. London: Harper Perennial.Google Scholar
- Schweinburger, S. R., & Burton, A. M. (2003). Covert recognition and the neural system for face processing. Cortex, 39, 9– 30.PubMed Web of Science®Google Scholar
- Somerfield, D. (1999). Capgras syndrome and animals. International Journal of Geriatric Psychiatry, 14( 10), 893– 894.Wiley Online Library CAS PubMed Web of Science®Google Scholar
- Tolkien, J. R. R. (1954). The fellowship of the ring. London: Allen & Unwin.Google Scholar
- Turkiewicz, G., Zanetti, M., Zung, S., & Cordeiro, Q. (2009). Coexistence of Capgras and Fregoli syndromes associated to frontotemporal volume reduction and cerebral white matter hyperintensities. Revista De Psiquiatria Clinica, 36( 6), 240– 247.Web of Science®Google Scholar
- Wolff, G., & McKenzie, K. (1994). Capgras, Fregoli and Cotard’s syndromes and Koro in folie a deux. British Journal of Psychiatry, 165( 6), 842.CAS PubMed Web of Science®Google Scholar
- Wright, S., Young, A., & Hellawell, D. (1993). Fregoli delusion and erotomania. Journal of Neurology, Neurosurgery & Psychiatry, 56( 3), 322– 323.Crossref CAS PubMed Web of Science®Google Scholar
- Young, A. H., Ellis, H. D., Szulecka, T., & de Pauw, K. W. (1990). Face processing impairments and delusional misidentification. Behavioural Neurology, 3( 3), 153– 168.Crossref CAS PubMed Google Scholar
- Young, A. W., Flude, B. M., & Ellis, A. W. (1991). Delusional misidentification incident in a right hemisphere stroke patient. Behavioural Neurology, 4( 2), 81– 87.Crossref CAS PubMed Google Scholar