The Fregoli Delusion: A Disorder of Person Identification and Tracking

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Abstract

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.

1 Introduction

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).