Psychopathy Part I

 

Psychopathy is a mental health condition characterized by persistent antisocial behavior, impaired empathy and remorse, and bold, disinhibited, and egotistical traits. Different conceptions of psychopathy have been used throughout history that are only partly overlapping and may sometimes be contradictory.

Hervey M. Cleckley, an American psychiatrist, influenced the initial diagnostic criteria for antisocial personality reaction/disturbance in the Diagnostic and Statistical Manual of Mental Disorders (DSM), as did American psychologist George E. Partridge. The DSM and International Classification of Diseases (ICD) subsequently introduced the diagnoses of antisocial personality disorder (ASPD) and dissocial personality disorder (DPD) respectively, stating that these diagnoses have been referred to (or include what is referred to) as psychopathy or sociopathy. The creation of ASPD and DPD was driven by the fact that many of the classic traits of psychopathy were impossible to measure objectively. Canadian psychologist Robert D. Hare later repopularized the construct of psychopathy in criminology with his Psychopathy Checklist.

Although no psychiatric or psychological organization has sanctioned a diagnosis titled "psychopathy", assessments of psychopathic characteristics are widely used in criminal justice settings in some nations and may have important consequences for individuals. The study of psychopathy is an active field of research. The term is also used by the general public, popular press, and in fictional portrayals. While the abbreviated term "psycho" is often employed in common usage in general media along with "crazy", "insane", and "mentally ill", there is a categorical difference between psychosis and psychopathy.

History

Etymology

The word psychopathy is a joining of the Greek words psyche (ψυχή) "soul" and pathos (πάθος) "suffering, feeling". The first documented use is from 1847 in Germany as psychopatisch, and the noun psychopath has been traced to 1885. In medicine, patho- has a more specific meaning of disease (thus pathology has meant the study of disease since 1610, and psychopathology has meant the study of mental disorder in general since 1847. A sense of "a subject of pathology, morbid, excessive" is attested from 1845, including the phrase pathological liar from 1891 in the medical literature).

The term psychopathy initially had a very general meaning referring to all sorts of mental disorders and social aberrations, popularized from 1891 in Germany by Koch's concept of "psychopathic inferiority" (psychopathische Minderwertigkeiten). Some medical dictionaries still define psychopathy in both a narrow and broad sense, such as MedlinePlus from the U.S. National Library of Medicine. On the other hand, Stedman's Medical Dictionary defines "psychopath" only as a "former designation" for a person with an antisocial type of personality disorder.

The term psychosis was also used in Germany from 1841, originally in a very general sense. The suffix -ωσις (-osis) meant in this case "abnormal condition". This term or its adjective psychotic would come to refer to the more severe mental disturbances and then specifically to mental states or disorders characterized by hallucinations, delusions or in some other sense markedly out of touch with reality.

 

The slang term psycho has been traced to a shortening of the adjective psychopathic from 1936, and from 1942 as a shortening of the noun psychopath, but it is also used as shorthand for psychotic or crazed.

The media usually uses the term psychopath to designate any criminal whose offenses are particularly abhorrent and unnatural, but that is not its original or general psychiatric meaning.

Sociopathy

The word element socio- has been commonly used in compound words since around 1880. The term sociopathy may have been first introduced in 1909 in Germany by biological psychiatrist Karl Birnbaum and in 1930 in the US by educational psychologist George E. Partridge, as an alternative to the concept of psychopathy. It was used to indicate that the defining feature is violation of social norms, or antisocial behavior, and may be social or biological in origin.

The term is used in various ways in contemporary usage. Robert Hare stated in the popular science book Snakes in Suits that sociopathy and psychopathy are often used interchangeably, but in some cases the term sociopathy is preferred because it is less likely than is psychopathy to be confused with psychosis, whereas in other cases the two terms may be used with different meanings that reflect the user's views on its origins and determinants. Hare contended that the term sociopathy is preferred by those that see the causes as due to social factors and early environment, and the term psychopathy preferred by those who believe that there are psychological, biological, and genetic factors involved in addition to environmental factors. Hare also provides his own definitions: he describes psychopathy as lacking a sense of empathy or morality, but sociopathy as only differing from the average person in the sense of right and wrong.

Precursors

Ancient writings that have been connected to psychopathic traits include Deuteronomy 21:18–21 and a description of an unscrupulous man by the Greek philosopher Theophrastus around 300 BC.

The concept of psychopathy has been indirectly connected to the early 19th century work of Pinel (1801; "mania without delirium") and Pritchard (1835; "moral insanity"), although historians have largely discredited the idea of a direct equivalence. Psychopathy originally described any illness of the mind, but found its application to a narrow subset of mental conditions when it was used toward the end of the 19th century by the German psychiatrist Julius Koch (1891) to describe various behavioral and moral dysfunction in the absence of an obvious mental illness or intellectual disability. He applied the term psychopathic inferiority (psychopathischen Minderwertigkeiten) to various chronic conditions and character disorders, and his work would influence the later conception of the personality disorder.

The term psychopathic came to be used to describe a diverse range of dysfunctional or antisocial behavior and mental and sexual deviances, including at the time homosexuality. It was often used to imply an underlying "constitutional" or genetic origin. Disparate early descriptions likely set the stage for modern controversies about the definition of psychopathy.

20th century

An influential figure in shaping modern American conceptualizations of psychopathy was American psychiatrist Hervey Cleckley. In his classic monograph, The Mask of Sanity (1941), Cleckley drew on a small series of vivid case studies of psychiatric patients at a Veterans Administration hospital in Georgia to provide a description for psychopathy. Cleckley used the metaphor of the "mask" to refer to the tendency of psychopaths to appear confident, personable, and well-adjusted compared to most psychiatric patients, while revealing underlying pathology through their actions over time. Cleckley formulated sixteen criteria for psychopathy. The Scottish psychiatrist David Henderson had also been influential in Europe from 1939 in narrowing the diagnosis.

The diagnostic category of sociopathic personality in early editions of the Diagnostic and Statistical Manual (DSM) had some key similarities to Cleckley's ideas, though in 1980 when renamed Antisocial Personality Disorder some of the underlying personality assumptions were removed. In 1980, Canadian psychologist Robert D. Hare introduced an alternative measure, the "Psychopathy Checklist" (PCL) based largely on Cleckley's criteria, which was revised in 1991 (PCL-R), and is the most widely used measure of psychopathy.[39] There are also several self-report tests, with the Psychopathic Personality Inventory (PPI) used more often among these in contemporary adult research.

Famous individuals have sometimes been diagnosed, albeit at a distance, as psychopaths. As one example out of many possible from history, in a 1972 version of a secret report originally prepared for the Office of Strategic Services in 1943, and which may have been intended to be used as propaganda, non-medical psychoanalyst Walter C. Langer suggested Adolf Hitler was probably a psychopath.[ However, others have not drawn this conclusion; clinical forensic psychologist Glenn Walters argues that Hitler's actions do not warrant a diagnosis of psychopathy as, although he showed several characteristics of criminality, he was not always egocentric, callously disregarding of feelings or lacking impulse control, and there is no proof he could not learn from mistakes.

Definition

Concepts

Psychopaths are social predators who charm, manipulate, and ruthlessly plow their way through life, leaving a broad trail of broken hearts, shattered expectations, and empty wallets. Completely lacking in conscience and in feelings for others, they selfishly take what they want and do as they please, violating social norms and expectations without the slightest sense of guilt or regret.—Robert D. Hare, 1993, p. xi

There are multiple conceptualizations of psychopathy, including Cleckleyan psychopathy (Hervey Cleckley's conception entailing bold, disinhibited behavior, and "feckless disregard") and criminal psychopathy (a meaner, more aggressive and disinhibited conception explicitly entailing persistent and sometimes serious criminal behavior). The latter conceptualization is typically used as the modern clinical concept and assessed by the Psychopathy Checklist. The label "psychopath" may have implications and stigma related to decisions about punishment severity for criminal acts, medical treatment, civil commitments, etc. Efforts have therefore been made to clarify the meaning of the term.

It has been suggested that those who share the same emotional deficiencies and psychopathic features, but are properly socialized, should not be designated as 'psychopaths'.

The triarchic model suggests that different conceptions of psychopathy emphasize three observable characteristics to various degrees. Analyses have been made with respect to the applicability of measurement tools such as the Psychopathy Checklist (PCL, PCL-R) and Psychopathic Personality Inventory (PPI) to this model.

Boldness. Low fear including stress-tolerance, toleration of unfamiliarity and danger, and high self-confidence and social assertiveness. The PCL-R measures this relatively poorly and mainly through Facet 1 of Factor 1. Similar to PPI fearless dominance. May correspond to differences in the amygdala and other neurological systems associated with fear.

Disinhibition. Poor impulse control including problems with planning and foresight, lacking affect and urge control, demand for immediate gratification, and poor behavioral restraints. Similar to PCL-R Factor 2 and PPI impulsive antisociality. May correspond to impairments in frontal lobe systems that are involved in such control.

Meanness. Lacking empathy and close attachments with others, disdain of close attachments, use of cruelty to gain empowerment, exploitative tendencies, defiance of authority, and destructive excitement seeking. The PCL-R in general is related to this but in particular some elements in Factor 1. Similar to PPI, but also includes elements of subscales in impulsive antisociality.

Measurement

An early and influential analysis from Harris and colleagues indicated that a discrete category, or taxon, may underlie PCL-R psychopathy, allowing it to be measured and analyzed. However, this was only found for the behavioral Factor 2 items they identified, child problem behaviors; adult criminal behavior did not support the existence of a taxon. Marcus, John, and Edens more recently performed a series of statistical analyses on PPI scores and concluded that psychopathy may best be conceptualized as having a "dimensional latent structure" like depression.

Marcus et al. repeated the study on a larger sample of prisoners, using the PCL-R and seeking to rule out other experimental or statistical issues that may have produced the previously different findings. They again found that the psychopathy measurements do not appear to be identifying a discrete type (a taxon). They suggest that while for legal or other practical purposes an arbitrary cut-off point on trait scores might be used, there is actually no clear scientific evidence for an objective point of difference by which to label some people "psychopaths"; in other words, a "psychopath" may be more accurately described as someone who is "relatively psychopathic".

The PCL-R was developed for research, not clinical forensic diagnosis, and even for research purposes to improve understanding of the underlying issues, it is necessary to examine dimensions of personality in general rather than only a constellation of traits.

Personality dimensions

Studies have linked psychopathy to alternative dimensions such as antagonism (high), conscientiousness (low) and anxiousness (low).

Psychopathy has also been linked to high psychoticism—a theorized dimension referring to tough, aggressive or hostile tendencies. Aspects of this that appear associated with psychopathy are lack of socialization and responsibility, impulsivity, sensation-seeking (in some cases), and aggression.

Otto Kernberg, from a particular psychoanalytic perspective, believed psychopathy should be considered as part of a spectrum of pathological narcissism that would range from narcissistic personality on the low end malignant narcissism in the middle, and psychopathy at the high end.

Psychopathy, narcissism and Machiavellianism, three personality traits that are together referred to as the dark triad, share certain characteristics, such as a callous-manipulative interpersonal style. The dark tetrad refers to these traits with the addition of sadism.

Criticism of current conceptions

The current conceptions of psychopathy have been criticized for being poorly conceptualized, highly subjective, and encompassing a wide variety of underlying disorders. Dorothy Otnow Lewis has written:

The concept and subsequent reification of the diagnosis "psychopathy" has, to this author's mind, hampered the understanding of criminality and violence. [...] According to Hare, in many cases one need not even meet the patient. Just rummage through his records to determine what items seemed to fit. Nonsense. To this writer's mind, psychopathy and its synonyms (e.g., sociopathy and antisocial personality) are lazy diagnoses. Over the years the authors' team has seen scores of offenders who, prior to evaluation by the authors, were dismissed as psychopaths or the like. Detailed, comprehensive psychiatric, neurological, and neuropsychological evaluations have uncovered a multitude of signs, symptoms, and behaviors indicative of such disorders as bipolar mood disorder, schizophrenia spectrum disorders, complex partial seizures, dissociative identity disorder, parasomnia, and, of course, brain damage/dysfunction.

Half of the Hare Psychopathy Checklist consists of symptoms of mania, hypomania, and frontal-lobe dysfunction, which frequently results in underlying disorders being dismissed. Hare's conception of psychopathy has also been criticized for being reductionist, dismissive, tautological, and ignorant of context as well as the dynamic nature of human behavior. Some have called for rejection of the concept altogether, due to its vague, subjective and judgmental nature that makes it prone to misuse.

Psychopathic individuals do not show regret or remorse. This was thought to be due to an inability to generate this emotion in response to negative outcomes. However, in 2016, people with antisocial personality disorder and dissocial personality disorder were found to experience regret, but did not use the regret to guide their choice in behavior. There was no lack of regret but a problem to think through a range of potential actions and estimating the outcome values.

In an experiment published in March 2007 at the University of Southern California neuroscientist Antonio R. Damasio and his colleagues showed that subjects with damage to the ventromedial prefrontal cortex lack the ability to empathically feel their way to moral answers, and that when confronted with moral dilemmas, these brain-damaged patients coldly came up with "end-justifies-the-means" answers, leading Damasio to conclude that the point was not that they reached immoral conclusions, but that when they were confronted by a difficult issue – in this case as whether to shoot down a passenger plane hijacked by terrorists before it hits a major city – these patients appear to reach decisions without the anguish that afflicts those with typically functioning brains. According to Adrian Raine, a clinical neuroscientist also at the University of Southern California, one of this study's implications is that society may have to rethink how it judges immoral people: "Psychopaths often feel no empathy or remorse. Without that awareness, people relying exclusively on reasoning seem to find it harder to sort their way through moral thickets. Does that mean they should be held to different standards of accountability?"

Signs and symptoms

Socially, psychopathy typically involves extensive callous and manipulative self-serving behaviors with no regard for others, and often is associated with repeated delinquency, crime and violence. Mentally, impairments in processes related to affect and cognition, particularly socially related mental processes, have also been found. Developmentally, symptoms of psychopathy have been identified in young children with conduct disorder, and suggest at least a partial constitutional factor that influences its development.

Primary features

Disagreement exists over which features should be considered as part of psychopathy, with researchers identifying around 40 traits supposedly indicative of the construct, though the following characteristics are almost universally considered central.

Core traits

Cooke and Michie (2001) proposed a three-factor model of the Psychopathy Checklist-Revised which has seen widespread application in other measures (e.g. Youth Psychopathic Traits Inventory, Antisocial Process Screening Device).

Arrogant and deceitful interpersonal style: impression management or superficial charm, inflated and grandiose sense of self-worth, pathological lying/deceit, and manipulation for personal gain.

Deficient affective experience: lack of remorse or guilt, shallow affect (coldness and unemotionality), callousness and lack of empathy, and failure to accept responsibility for own actions.

Impulsive and irresponsible lifestyle: impulsivity, sensation-seeking and risk-taking, irresponsible and unreliable behavior, financially parasitic lifestyle and lack of realistic, long-term goals.

Low anxiety and fearlessness

Cleckley's (1941) original description of psychopathy included the absence of nervousness and neurotic disorders, and later theorists referred to psychopaths as fearless or thick-skinned. While it is often claimed that the PCL-R does not include low anxiety or fearlessness, such features do contribute to the scoring of the Facet 1 (interpersonal) items, mainly through self-assurance, unrealistic optimism, brazenness and imperturbability. Indeed, while self-report studies have been inconsistent using the two-factor model of the PCL-R, studies which separate Factor 1 into interpersonal and affective facets, more regularly show modest associations between Facet 1 and low anxiety, boldness and fearless dominance (especially items assessing glibness/charm and grandiosity). When both psychopathy and low anxiety/boldness are measured using interviews, both interpersonal and affective facets are both associated with fearlessness and lack of internalizing disorders.

The importance of low anxiety/fearlessness to psychopathy has historically been underscored through behavioral and physiological studies showing diminished responses to threatening stimuli (interpersonal and affective facets both contributing). However, it is not known whether this is reflected in reduced experience of state fear or where it reflects impaired detection and response to threat-related stimuli. Moreover, such deficits in threat responding are known to be reduced or even abolished when attention is focused on the threatening stimuli.

Offending

Criminality

Psychopathy is strongly correlated with crime, violence, and antisocial behavior.

In terms of simple correlations, the PCL-R manual states an average score of 22.1 has been found in North American prisoner samples, and that 20.5% scored 30 or higher. An analysis of prisoner samples from outside North America found a somewhat lower average value of 17.5. Studies have found that psychopathy scores correlated with repeated imprisonment, detention in higher security, disciplinary infractions, and substance misuse.

Psychopathy, as measured with the PCL-R in institutional settings, shows in meta-analyses small to moderate effect sizes with institutional misbehavior, post-release crime, or post-release violent crime with similar effects for the three outcomes. Individual studies give similar results for adult offenders, forensic psychiatric samples, community samples, and youth. The PCL-R is poorer at predicting sexual re-offending. This small to moderate effect appears to be due largely to the scale items that assess impulsive behaviors and past criminal history, which are well-established but very general risk factors. The aspects of core personality often held to be distinctively psychopathic generally show little or no predictive link to crime by themselves. For example, Factor 1 of the PCL-R and Fearless dominance of the PPI-R have smaller or no relationship to crime, including violent crime. In contrast, Factor 2 and Impulsive antisociality of the PPI-R are associated more strongly with criminality. Factor 2 has a relationship of similar strength to that of the PCL-R as a whole. The antisocial facet of the PCL-R is still predictive of future violence after controlling for past criminal behavior which, together with results regarding the PPI-R which by design does not include past criminal behavior, suggests that impulsive behaviors are an independent risk factor. Thus, the concept of psychopathy may perform poorly when attempted to be used as a general theory of crime.

Violence

Studies have suggested a strong correlation between psychopathy scores and violence, and the PCL-R emphasizes features that are somewhat predictive of violent behavior. Researchers, however, have noted that psychopathy is dissociable from and not synonymous with violence.

It has been suggested that psychopathy is associated with "instrumental aggression", also known as predatory, proactive, or "cold blooded" aggression, a form of aggression characterized by reduced emotion and conducted with a goal differing from but facilitated by the commission of harm. One conclusion in this regard was made by a 2002 study of homicide offenders, which reported that the homicides committed by homicidal offenders with psychopathy were almost always (93.3%) primarily instrumental, significantly more than the proportion (48.4%) of those committed by non-psychopathic homicidal offenders, with the instrumentality of the homicide also correlated with the total PCL-R score of the offender as well as their scores on the Factor 1 "interpersonal-affective" dimension. However, contrary to the equating of this to mean exclusively "in cold blood", more than a third of the homicides committed by psychopathic offenders involved some component of emotional reactivity as well. In any case, FBI profilers indicate that serious victim injury is generally an emotional offense, and some research supports this, at least with regard to sexual offending. One study has found more serious offending by non-psychopathic offenders on average than by offenders with psychopathy (e.g. more homicides versus more armed robbery and property offenses) and another that the Affective facet of the PCL-R predicted reduced offense seriousness.

Studies on perpetrators of domestic violence find that abusers have high rates of psychopathy, with the prevalence estimated to be at around 15-30%. Furthermore, the commission of domestic violence is correlated with Factor 1 of the PCL-R, which describes the emotional deficits and the callous and exploitative interpersonal style found in psychopathy. The prevalence of psychopathy among domestic abusers indicate that the core characteristics of psychopathy, such as callousness, remorselessness, and a lack of close interpersonal bonds, predispose those with psychopathy to committing domestic abuse, and suggest that the domestic abuses committed by these individuals are callously perpetrated (i.e. instrumentally aggressive) rather than a case of emotional aggression and therefore may not be amenable to the types of psychosocial interventions commonly given to domestic abuse perpetrators.

Some clinicians suggest that assessment of the construct of psychopathy does not necessarily add value to violence risk assessment. A large systematic review and meta-regression found that the PCL performed the poorest out of nine tools for predicting violence. In addition, studies conducted by the authors or translators of violence prediction measures, including the PCL, show on average more positive results than those conducted by more independent investigators. There are several other risk assessment instruments which can predict further crime with accuracy similar to the PCL-R and some of these are considerably easier, quicker, and less expensive to administer. This may even be done automatically by a computer simply based on data such as age, gender, number of previous convictions and age of first conviction. Some of these assessments may also identify treatment change and goals, identify quick changes that may help short-term management, identify more specific kinds of violence that may be at risk, and may have established specific probabilities of offending for specific scores. Nonetheless, the PCL-R may continue to be popular for risk assessment because of its pioneering role and the large amount of research done using it.

The Federal Bureau of Investigation reports that psychopathic behavior is consistent with traits common to some serial killers, including sensation seeking, a lack of remorse or guilt, impulsivity, the need for control, and predatory behavior. It has also been found that the homicide victims of psychopathic offenders were disproportionately female in comparison to the more equitable gender distribution of victims of non-psychopathic offenders.

Sexual offending

Psychopathy has been associated with commission of sexual crime, with some researchers arguing that it is correlated with a preference for violent sexual behavior. A 2011 study of conditional releases for Canadian male federal offenders found that psychopathy was related to more violent and non-violent offences but not more sexual offences.[citation needed] For child molesters, psychopathy was associated with more offences. A study on the relationship between psychopathy scores and types of aggression in a sample of sexual murderers, in which 84.2% of the sample had PCL-R scores above 20 and 47.4% above 30, found that 82.4% of those with scores above 30 had engaged in sadistic violence (defined as enjoyment indicated by self-report or evidence) compared to 52.6% of those with scores below 30, and total PCL-R and Factor 1 scores correlated significantly with sadistic violence. Despite this, it is reported that offenders with psychopathy (both sexual and non-sexual offenders) are about 2.5 times more likely to be granted conditional release compared to non-psychopathic offenders.

Hildebrand and colleagues (2004) have uncovered an interaction between psychopathy and deviant sexual interests, wherein those high in psychopathy who also endorsed deviant sexual interests were more likely to recidivate sexually. A subsequent meta-analysis has consolidated such a result.

In considering the issue of possible reunification of some sex offenders into homes with a non-offending parent and children, it has been advised that any sex offender with a significant criminal history should be assessed on the PCL-R, and if they score 18 or higher, then they should be excluded from any consideration of being placed in a home with children under any circumstances. There is, however, increasing concern that PCL scores are too inconsistent between different examiners, including in its use to evaluate sex offenders.

Other offending

The possibility of psychopathy has been associated with organized crime, economic crime and war crimes. Terrorists are sometimes considered psychopathic, and comparisons may be drawn with traits such as antisocial violence, a selfish world view that precludes the welfare of others, a lack of remorse or guilt, and blame externalization. However, John Horgan, author of The Psychology of Terrorism, argues that such comparisons could also then be drawn more widely: for example, to soldiers in wars. Coordinated terrorist activity requires organization, loyalty and ideological fanaticism often to the extreme of sacrificing oneself for an ideological cause. Traits such as a self-centered disposition, unreliability, poor behavioral controls, and unusual behaviors may disadvantage or preclude psychopathic individuals in conducting organized terrorism.

It may be that a significant portion of people with psychopathy are socially successful and tend to express their antisocial behavior through more covert avenues such as social manipulation or white collar crime. Such individuals are sometimes referred to as "successful psychopaths", and may not necessarily always have extensive histories of traditional antisocial behavior as characteristic of traditional psychopathy.

Childhood and adolescent precursors

The PCL: YV is an adaptation of the PCL-R for individuals aged 13–18 years. It is, like the PCL-R, done by a trained rater based on an interview and an examination of criminal and other records. The "Antisocial Process Screening Device" (APSD) is also an adaptation of the PCL-R. It can be administered by parents or teachers for individuals aged 6–13 years. High psychopathy scores for both juveniles, as measured with these instruments, and adults, as measured with the PCL-R and other measurement tools, have similar associations with other variables, including similar ability in predicting violence and criminality. Juvenile psychopathy may also be associated with more negative emotionality such as anger, hostility, anxiety, and depression. Psychopathic traits in youth typically comprise three factors: callous/unemotional, narcissism, and impulsivity/irresponsibility.

There is positive correlation between early negative life events of the ages 0–4 and the emotion-based aspects of psychopathy. There are moderate to high correlations between psychopathy rankings from late childhood to early adolescence. The correlations are considerably lower from early- or mid-adolescence to adulthood. In one study most of the similarities were on the Impulsive- and Antisocial-Behavior scales. Of those adolescents who scored in the top 5% highest psychopathy scores at age 13, less than one third (29%) were classified as psychopathic at age 24. Some recent studies have also found poorer ability at predicting long-term, adult offending.

Conduct disorder

Conduct disorder is diagnosed based on a prolonged pattern of antisocial behavior in childhood and/or adolescence, and may be seen as a precursor to ASPD. Some researchers have speculated that there are two subtypes of conduct disorder which mark dual developmental pathways to adult psychopathy. The DSM allows differentiating between childhood onset before age 10 and adolescent onset at age 10 and later. Childhood onset is argued to be more due to a personality disorder caused by neurological deficits interacting with an adverse environment. For many, but not all, childhood onset is associated with what is in Terrie Moffitt's developmental theory of crime referred to as "life-course- persistent" antisocial behavior as well as poorer health and economic status. Adolescent onset is argued to more typically be associated with short-term antisocial behavior.

It has been suggested that the combination of early-onset conduct disorder and ADHD may be associated with life-course-persistent antisocial behaviors as well as psychopathy. There is evidence that this combination is more aggressive and antisocial than those with conduct disorder alone. However, it is not a particularly distinct group since the vast majority of young children with conduct disorder also has ADHD. Some evidence indicates that this group has deficits in behavioral inhibition, similar to that of adults with psychopathy. They may not be more likely than those with conduct disorder alone to have the interpersonal/affective features and the deficits in emotional processing characteristic of adults with psychopathy. Proponents of different types/dimensions of psychopathy have seen this type as possibly corresponding to adult secondary psychopathy and increased disinhibition in the triarchic model.

The DSM-5 includes a specifier for those with conduct disorder who also display a callous, unemotional interpersonal style across multiple settings and relationships. The specifier is based on research which suggests that those with conduct disorder who also meet criteria for the specifier tend to have a more severe form of the disorder with an earlier onset as well as a different response to treatment. Proponents of different types/dimensions of psychopathy have seen this as possibly corresponding to adult primary psychopathy and increased boldness and/or meanness in the triarchic model.

Mental traits

Cognition

Dysfunctions in the prefrontal cortex and amygdala regions of the brain have been associated with specific learning impairments in psychopathy. Since the 1980s, scientists have linked traumatic brain injury, including damage to these regions, with violent and psychopathic behavior. Patients with damage in such areas resembled "psychopathic individuals" whose brains were incapable of acquiring social and moral knowledge; those who acquired damage as children may have trouble conceptualizing social or moral reasoning, while those with adult-acquired damage may be aware of proper social and moral conduct but be unable to behave appropriately. Dysfunctions in the amygdala and ventromedial prefrontal cortex may also impair stimulus-reinforced learning in psychopaths, whether punishment-based or reward-based. People scoring 25 or higher in the PCL-R, with an associated history of violent behavior; appear to have significantly reduced mean microstructural integrity in their uncinate fasciculus—white matter connecting the amygdala and orbitofrontal cortex. There is evidence from DT-MRI of breakdowns in the white matter connections between these two important areas.

Although some studies have suggested inverse relationships between psychopathy and intelligence, including with regards to verbal IQ, Hare and Neumann state that a large literature demonstrates at most only a weak association between psychopathy and IQ, noting that the early pioneer Cleckley included good intelligence in his checklist due to selection bias (since many of his patients were "well educated and from middle-class or upper-class backgrounds") and that "there is no obvious theoretical reason why the disorder described by Cleckley or other clinicians should be related to intelligence; some psychopaths are bright, others less so". Studies also indicate that different aspects of the definition of psychopathy (e.g. interpersonal, affective (emotion), behavioral and lifestyle components) can show different links to intelligence, and the result can depend on the type of intelligence assessment (e.g. verbal, creative, practical, analytical).