Features of other relevant concepts

Antisocial personality disorder

Diagnostic features

To appreciate the key features and boundaries of narcissistic personality disorder, an understanding of antisocial personality disorder, as well as two overlapping traits, psychopathy and sociopathy, may be helpful. According to the DSM V, individuals may be diagnosed with antisocial personality disorder if, since the age of 14, they have exhibited three of the following signs or symptoms, each of which demonstrate an inclination to disregard or violate the rights of other people:

recurrent actions that violate laws or norms, such as theft or harassment, to the extent these acts may be grounds for arrest,
repeated lying or deceit, often to seek money, sex, or power,
impulsive actions or decisions, often without consideration of consequences, such as shifting jobs erratically,
repeated assaults or fights, including at home,
reckless disregard of safety, such as driving while intoxicated or substance abuse,
an inability to work consistently or honour financial obligations, such as debts, with negligible remorse,
indifference, rather than remorse, after hurting or mistreating someone, sometimes including a tendency to blame victims.

Nevertheless, individuals are not diagnosed with this disorder unless they are adults and had been diagnosed with conduct disorder before the age of 14—a disorder that entails aggression, destruction of property, deceit or threat, as well as serious breaches of rules. Furthermore, if individuals exhibit these symptoms only during a bout of schizophrenia or bipolar disorder, they will not be diagnosed with antisocial personality disorder.

Other features

Individuals who are diagnosed with antisocial personality disorder often exhibit other tendencies or behaviours as well. For example, these individuals

tend to be cynical or contemptuous of the feelings or concerns of other people rather than empathic or compassionate,
may seem opinionated or conceited and inflate their qualities,
often display superficial charm and use many technical or sophisticated words to express themselves,
seem irresponsible in relationship, such as fail to sustain romances or care for their children responsibly.

Antisocial personality disorder is observed in about 3.6% of the population, although six of the seven samples from which this figure was derived were US adults (Morgan & Zimmerman 2018). About 70% of individuals diagnosed with antisocial personality disorder are men. Some of the manifestations of antisocial personality disorder may subside after the age of 40 (Black, 2015).quiet ego scale has been validated in other settings and nations. For example, Bernabei et al. (2024) validated this scale at an Italian university, in which the participants were 160 university students, ranging in age from 20 to 42. The study revealed that a quiet ego was positively associated with measures of resilience, happiness, and psychological wellbeing.

Sociopathy

Evolution of this term

Many people violate the norms of society and the rights of other people. In the 1920s and 1930s, George Partridge, an American psychologist, discussed the implications of this behaviour (Partridge, 1928; Partridge, 1930). He also ascribed these behaviours to problems in the social environment, such as parental rejection during childhood. Consequently, he proposed the term sociopath to label these individuals (Partridge, 1930).

About a decade later, in his renowned book entitled “The mast of sanity”, Hervey Cleckley attempted to delineate the traits of psychopaths—a term that psychiatrists had used for many decades to describe people who often perpetrated unlawful, deceptive, impulsive, aggressive, risky, and callous behaviour. Primarily derived from clinical observations of 15 individuals, he characterised these psychopaths as individuals who exhibited superficial charm but were callous and devoid of remorse or shame (Cleckley, 1941).

Specifically, in the first edition of his book, published in 1941, Cleckley identified 21 criteria that practitioners may assess to diagnose psychopathy. In 1976, the fifth edition of his book diminished this number to 16. These criteria include

superficial charm,
absence of delusions; absence of nervousness; rare suicidal behaviour
unreliability, untruthfulness,
limited remorse or shame; poverty in affective reactions,
antisocial behaviour; pathological egocentricity
fantastic and uninviting behaviour
failure to learn by experience; loss of insight; failure to follow any life plan,
unresponsiveness in interpersonal relations; impersonal sex life.

Therefore, during these decades, the terms sociopathy and psychopathy largely evolved from distinct strands of literature. Yet, because these terms referred to overlapping and similar patterns of behaviours, both academics and practitioners often used the words sociopathy and psychopathy interchangeably.

In 1952, the first edition of the DSM, however, utilised the term sociopathic personality disturbance to label people who breach the norms of society and the rights of other people. This reference to sociopathy, rather than psychopathy, was preferred because of several reasons. First, as Robert Hare later discussed in his book “Snakes in suits”, the public sometimes confused the term psychopath and psychotic—a problem that other labels, such as sociopath, prevented. Second, the DSM at this time primarily ascribed this behaviour to problems in the social environment. Third, the behaviours were deemed as inappropriate if they violated rules that are socially constructed—such as laws or cultural norms. In 1968, however, the DSM II refined the definition of this disturbance but labelled this pattern of behaviour as antisocial personality.

Differences between sociopathy and psychopathy

Since this time, researchers and clinicians have generally regarded sociopathy and psychopathy as severe manifestations of antisocial personality disorder (Johnson, 2019). About 30% of the individuals who are diagnosed with antisocial personality disorder also exhibit sociopathy, whereas about 3 to 15% of individuals who are diagnosed with antisocial personality disorder also exhibit psychopathy, although the precise figure depends on the definition of these characteristics.

Because of this overlap with antisocial personality disorder, sociopathy and psychopathy are similar. Despite their similarities, researchers often allude to several key differences (e.g., Gagne, 2024; Hare, 2006; Johnson, 2019; Pemment, 2013):

generally, sociopathy is more likely to be largely ascribed to adverse events or experiences, such as child abuse, permissive parenting, or severe family dysfunction, that compromise socialisation; psychopathy is more likely to be ascribed primarily to biological aberrations at birth—such as genes that diminish susceptibility to fear and anxiety (Lykken, 1995),
people who exhibit sociopathy are more likely than people who exhibit psychopathy to establish close bonds with one collective, such as their family or a gang,
whereas people who exhibit psychopathy experience negligible remorse, people who exhibit sociopathy may express some remorse in response to hurting their closest affiliates,
people who exhibit sociopathy are more likely than people who exhibit psychopathy to be impulsive—and thus not as able to conceal their inclinations, maintain a job, or prevent incarceration,
people who exhibit sociopathy are more likely than people who exhibit psychopathy are more prone to angry or violent outbursts,
treatment of both disorders tends to be ineffective, but people who exhibit sociopathy seldom cooperate with treatment regimes, whereas people who exhibit psychopathy often feign changes in their behaviour.

Thus, in contrast to psychopathy, sociopathy is more likely coincide with some genuine relationships, albeit limited in number, some moral reasoning, as well as impulsive acts, sometimes compromising the capacity of these individuals to conceal their tendencies and avoid prison.

Nevertheless, in contrast to antisocial personality disorder and psychopathy, the definition and boundaries of sociopathy remain hazy. That is, despite some variation and controversy, antisocial personality disorder can often be equated to the definitions and properties that appear in the DSM V. Psychopathy can be equated to some common indices and scales, such as the renowned psychopathy checklist (Hare et al., 1990). In contrast, researchers and practitioners have not developed a standard definition, taxonomy, or measure of sociopathy—although the socialisation scale from the California Psychological Inventory is one possible candidate, as Cooney et al. (1990) recommended in a study of alcoholics.

Acquired sociopathy

Typically, researchers ascribe sociopathy to adverse experiences during childhood. However, as many case studies reveal, some people exhibit the hallmarks of sociopathy only after they experience brain injury, especially in the orbitofrontal cortex or related circuits (for an overview of this region, see Rolls, 2004). This change in behaviour is often labelled acquired sociopathy (e.g., Blair and Cipolotti, 2000).

The most renowned example of acquired sociopathy is the case of Phineas Gage, a railroad worker, in the mid 1800s, whose personality transformed after a tamping iron, similar to a crowbar, penetrated his left frontal lobe (Harlow, 1848) and probably his ventromedial prefrontal cortex (Damasio et al., 1994)—a region that overlaps anatomically and functionally with the orbitofrontal cortex. Although perceived as intelligent and energetic before his injury, he was described as disrespectful, impulsive, obstinate, and profane afterwards (Harlow, 1868). His indifference to social conventions is reminiscent of modern definitions of sociopathy. As an aside, Phineas Gage may have recovered to be more responsible than often assumed (Macmillan & Lena, 2010). For example, after his accident,

for 7 years, he was employed as a coach driver in Chile, implying that he adapted to the language and social norms of the nation,
towards the end of his life, a doctor, who had also known him before the accident, did not report any apparent impairment.

The term acquired sociopathy, however, was first applied many years later, to describe a patient who transformed from a successful person, with a solid marriage, to an individual who experienced failed marriages and businesses after his orbitofrontal cortex was damaged (Eslinger & Damasio, 1985). These changes were observed even though his intelligence remained intact and no other brain circuits were lesioned. The individual exhibited negligible remorse and minimal concern for the needs of other people. These changes lasted at least eight years.

Nevertheless, the term acquired sociopathy is, arguably, applied loosely. For example, this term is not used to differentiate sociopathy from psychopathy or antisocial personality disorder. To illustrate, researchers have utilised this term to label individuals who have experienced neurological decline, such as dementia, together with behaviours that violate social norms or the rights of other people—including physical assault, theft, indecent exposure (e.g., Mendez et al., 2011).

Psychopathy

In contrast to sociopathy, researchers have developed many instruments to measure psychopathy, such as the Hare Psychopathy Checklist. Indeed, scholars often refer to these instruments when defining and delineating psychopathy.

The stability of psychopathy during childhood and adolescence

Many studies have explored the extent to which psychopathy tends to persist over the lifespan. That is, significant research has examined whether the signs or manifestations of psychopathy during childhood are observed in adolescence and adulthood as well.

To illustrate, in one informative study, Obradović et al (2007) administered the Inventory of Interpersonal Callousness to parents of boys aged 8, recruited from the Pittsburgh Youth Study. The researchers then repeated this procedure annually until these children reached 16. The study uncovered elevated latent-factor correlations across the years, such as

.77 between ratings at age 8 and ratings at age 10,
.66 between ratings at age 8 and ratings at age 12,
.50 between ratings at age 8 and ratings at age 16.

These findings suggest that at least one facet of psychopathy, interpersonal callousness, is relatively stable over time (for similar findings, but with a broader measure of psychopathy, see Frick et al., 2003). Indeed, some features of psychopathy might even manifest before the age of 8. Barker et al. (2011) revealed that a fearless temperament at age 2, as measured by the Carey Infant Scale, is strongly and positively associated with callous, unemotional features at age 13—even after controlling parental risks.

The stability of psychopathy over the lifespan

Other studies have explored whether psychopathy also persists from adolescence to adulthood. To illustrate, in one industrious study, Bergstrøm and Farrington (2021) assessed over 400 males, living in London, recruited from the Cambridge Study in Delinquent Development. The participants completed relevant measures of psychopathy—such as the Antisocial Process Screening Device or the Psychopathy Checklist – Screening Version—every two years, from 8 to 18 and then later at ages 32 and 48. As this study revealed

if children demonstrated psychopathy at ages 8 to 10, they were 3.2 times as likely as other children to also demonstrate psychopathy at ages 12 to 14,
however, if adolescents demonstrated psychopathy at ages 12 to 14, they were only 1.68 times as likely as other adolescents to also demonstrate psychopathy at ages 16 to 18,
similarly, if adolescents demonstrated psychopathy at ages 16 to 18, they were only 1.51 times as likely as other adolescents to also demonstrate psychopathy at age 32.
finally, if adults demonstrated psychopathy at age 32, they were 3.5 times as likely as other adults to also demonstrate psychopathy at age 48.

Taken together, these findings imply that during childhood—and during adulthood—levels of psychopathy in individuals seem relatively stable over time. In contrast, during late adolescence or during the transition from adolescence to adulthood, psychopathy in individuals is more likely to shift appreciably. More specifically, as other studies have revealed,

from the ages of 17 to 24, levels of psychopathy, as gauged by the Psychopathy Checklist Youth Version, tend to diminish over time (Hawes et al., 2014),
however, the effect size of this decrease is small to medium, in which d = .34 (Hawes et al., 2014),
between the ages of 14 to 23, about a third of individuals demonstrate significant changes in the Youth Psychopathic Traits Inventory—and the majority of these changes are decreases in psychopathy (McCuish & Lussier, 2018).

Almas and Lordos (2025) ascribed this pattern of change over time, especially the decline in psychopathy around late adolescence and early adulthood, to several possible explanations:

First, this decrease in psychopathy may emanate from biological changes, such as increased myelination, coupled with social changes, such as increased responsibility.
Second, researchers may overestimate the number of children who exhibit psychopathy, because these children may be mimicking behaviours or attitudes they observe—a tendency that might diminish with age,
Third, as individuals age, they can perhaps more readily conceal their psychopathic tendencies, but core levels of these features do not change.

Munchausen by Proxy: Factitious Disorder Imposed on Another

Many people are aware of Munchausen Syndrome by Proxy. A typical case is when parents deliberately induce a disease, illness, or injury in one or more of their children or erroneously maintain their children are ill. Officially, people who perpetrate this behaviour—in which they fabricate or induce disease in another person—are diagnosed with Factitious Disorder Imposed on Another. Although the causes or antecedents of this disorder are uncertain and multifaceted, individuals who perpetrate these behaviours seem to experience a need to attract recognition, attention, and sympathy, reminiscent of narcissism (Saad, 2010; see also Hamilton & Janata, 1997).

Typically, people who exhibit Factitious Disorder Imposed on Another are diagnosed with other personality disorders as well, such as borderline personality disorder (Yates & Bass, 2017). Limited research, however, has assessed the degree to which narcissism is related to Factitious Disorder Imposed on Another or could explain this disorder (for cases in which individuals exhibited both factitious and narcissistic disorders, see Fischer et al., 2017; Thompson & Beckson, 2004). To overcome this shortfall, Barker et al. (2025), at a recent conference, presented a paper in which they

first developed a self-report measure of Factitious Disorder Imposed on Another,
second, in a sample of 623 individuals, assessed whether scores on this measure are associated with scores on the Pathological Narcissism Inventory, comprising questions like “I get mad when people don’t notice all I do for them”.

The data revealed a positive correlation between Factitious Disorder Imposed on Another and the two main facets of narcissism: grandiose narcissism, r = .154, and vulnerable narcissism, r = .150. Presumably, narcissistic individuals often like to seek attention, often dishonestly, increasing the likelihood of Factitious Disorder Imposed on Another.

Future research should explore whether the association between narcissism and Factitious Disorder Imposed on Another depends on the motivations of parents. To illustrate, parents may induce these illness in their children to fulfill a range of goals, not all of which revolve around the need to attract recognition. For example, according to Libow and Schreier (1986), some parents may perpetrate these behaviours merely to seek assistance on a private matter—and thus will concoct the illness to contrive opportunities in which they can express their distress.

Other possible causes and antecedents: An overview

In principle, other experiences or characteristics may increase the likelihood that narcissism could manifest as Factitious Disorder Imposed on Another. To predict which experiences or characteristics may increase this likelihood, researchers should consider the other determinants of Factitious Disorder Imposed on Another (for reviews, see Abdurrachid & Marques, 2022; Dickerman & Jiménez, 2023). According to a systematic review that Yates and Bass (2017) published, Factitious Disorder Imposed on Another tends to coincide with the following features:

Individuals who are diagnosed with this disorder are more likely to be female (97%), married (76%), and often working in roles that relate to health care (46%).
This diagnosis is sometimes co-morbid with depression (14%), personality disorders—especially borderline (19%), substance or alcohol abuse (14%), and pathological lying (9.2%).
Individuals who are diagnosed with this disorder had often experienced mistreatment as a child (30%), reported obstetric complications in (24%), or perpetrated criminal behaviours (10%).

Insights from psychiatric assessments

To explore the causes or determinants of Factitious Disorder Imposed on Another, Bass and Jones (2011) conducted a psychological assessment of 28 women who had been diagnosed with this disorder or suspected, by a social services agency, to exhibit this disorder. The researchers conducted an extensive analysis of the medical and psychiatric history of each person—deriving insights from the reports of social workers, case conferences, medical notes, and other reliable sources. Many of these participants had experienced challenging circumstances. For example

the majority of individuals were unemployed or granted a disability living allowance,
24 of the 28 individuals had experienced a loss of a parent or separation of a parent before the age of 11
54% of the participants had been severely abused as children, 43% reported sexual abuse, and 39% had lived in foster care.

This abuse might have provoked the need in these individuals to be deceptive. To illustrate, during early childhood, some of these individuals had feigned symptoms to prevent beatings or contact from abusive parents. Furthermore, many of these individuals demonstrated other psychiatric conditions:

61% had been referred to child or adolescent psychiatric services, often because of disruptive behaviour, anxiety, depression, or eating disorders,
54% demonstrated a history of self-harm,
75% exhibited a personality disorder, usually antisocial, borderline, histrionic, or dependent,
57% could be diagnosed with somatisation disorder—because of physical complaints that lasted over 2 years with no organic cause,
61% had fabricated stories, suggesting the possibility of pathological lying.

Likewise, Bools et al. (1994) had conducted a similar research project, except these researchers also interviewed some of the mothers when appropriate. As these researchers discovered, in a sample of 56 mothers

55% exhibited self-harm, 21% exhibited alcohol or substance abuse, and 72% exhibited somatising disorder,
16% had been charged with crimes, such as theft or fraud,
many of these individuals had experienced challenges at home; 78% of the 19 mothers interviewed had endured emotional neglect or abuse, for example,
many of these individuals experienced various mental illnesses, such as personality disorders; 26%, for example, had experienced learning difficulties in the past.