Misplaced Pages

Psychopathy: Difference between revisions

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.
Browse history interactively
← Previous editNext edit →Content deleted Content addedVisualWikitext
Revision as of 15:52, 10 July 2011 editMiradre (talk | contribs)9,214 edits Stroop tasks: intelligence← Previous edit Revision as of 15:52, 10 July 2011 edit undoMiradre (talk | contribs)9,214 edits Intelligence: fixNext edit →
Line 38: Line 38:


====Intelligence==== ====Intelligence====
Hare and Neumann (2008) states that there is at most a only a weak association between psychopathy and IQ. "Moreover, 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."<ref>{{doi|10.1146/annurev.clinpsy.3.022806.091452}}</ref> Hare and Neumann (2008) states that there is at most a only a weak association between psychopathy and IQ. "Moreover, 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."<ref>{{cite doi|10.1146/annurev.clinpsy.3.022806.091452}}</ref>


==Causes and pathophysiology== ==Causes and pathophysiology==

Revision as of 15:52, 10 July 2011

"Psychopath" redirects here. For other uses, see Psychopath (disambiguation). Not to be confused with Psychosis, Psychopathology, or Autistic Psychopathy.

Psychopathy (/saɪˈkɒpəθi/) is a term which, until the 1980s, formally referred to a personality disorder characterized by the inability to form human attachment and an abnormal lack of empathy, masked by an ability to appear outwardly normal. The publication of the Diagnostic and Statistical Manual of Mental Disorders third edition (DSM-III) changed the name of this mental disorder to antisocial personality disorder, and also broadened the diagnostic criteria considerably by shifting from clinical inferences to behavioral diagnostic criteria. However, the DSM-V working party is recommending a revision of antisocial personality disorder to include "Antisocial/Psychopathic Type", with the diagnostic criteria having a greater emphasis on character than on behavior. The ICD-10 diagnostic criteria of the World Health Organization also lacks psychopathy as a personality disorder. The 1992 manual included dissocial (antisocial) personality disorder, which encompasses amoral, antisocial, asocial, psychopathic, and sociopathic personalities.

Despite being currently unused in diagnostic manuals, psychopathy and related terms such as psychopath are still widely used by mental health professionals and laymen alike. In particular, NATO has funded a series of Advanced Study Institutes on psychopathy, both before and after the publication of DSM-III. Researcher Robert Hare has been a particular champion of the term; his Hare Psychopathy Checklist is the standard tool for differentiating between those with antisocial personality disorder and the subset who are psychopaths. According to this scale the prevalence of antisocial personality disorder is two to three times that of psychopathy.

According to a chapter about treatment in Christopher J. Patrick's Handbook of Psychopathy, there is little evidence of a cure or any effective treatment for psychopathy; no medications can instill empathy, and psychopaths who undergo traditional talk therapy might become more adept at manipulating others and more likely to commit crime. Others suggest that psychopaths may benefit as much as others from psychological treatment, at least in terms of effect on behavior. According to Hare, the consensus among researchers in this area is that psychopathy stems from a specific neurological disorder which is present from birth, although a 2008 review indicated multiple causes and variation between individuals. Hare estimates that about one percent of the population are psychopaths.

Classification

Main article: Classification of mental disorder

The classification of mental disorders, also known as psychiatric nosology or taxonomy, is a key aspect of psychiatry and other mental health professions and an important issue for consumers and providers of mental health services. There are currently two widely established systems for classifying mental disorders — Chapter V of the International Classification of Diseases (ICD-10) produced by the World Health Organization (WHO) and the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) produced by the American Psychiatric Association (APA). Both list categories of disorders thought to be distinct types, and have deliberately converged their codes in recent revisions so that the manuals are often broadly comparable, although significant differences remain. Less widely accepted classification schemes may be in use more locally, for example the Chinese Classification of Mental Disorders. Other manuals have some limited used by those of alternative theoretical persuasions, such as the Psychodynamic Diagnostic Manual.

Characteristics

The prototypical psychopath has deficits or deviance in several areas: interpersonal relationships, emotion, and behavior. Psychopaths gain satisfaction through antisocial behavior, and do not experience shame, guilt, or remorse for their actions. Psychopaths lack a sense of guilt or remorse for any harm they may have caused others, instead rationalizing the behavior, blaming someone else, or denying it outright. Psychopaths also lack empathy towards others in general, resulting in tactlessness, insensitivity, and contemptuousness. Psychopaths can have a superficial charm about them, enabled by a willingness to say anything to anyone without concern for accuracy or truth. Shallow affect also describes the psychopath's tendency for genuine emotion to be short-lived, glib and egocentric, with an overall cold demeanor. Their behavior is impulsive and irresponsible, often failing to keep a job or defaulting on debts.

Researcher Robert Hare, whose Hare Psychopathy Checklist is widely used, describes psychopaths as "intraspecies predators". Also R.I. Simon uses the word predator to describe psychopaths. Elsewhere Hare and others write that psychopaths "use charisma, manipulation, intimidation, sexual intercourse and violence" to control others and to satisfy their own needs. Hare states that: "Lacking in conscience and empathy, they take what they want and do as they please, violating social norms and expectations without guilt or remorse". He previously stated that: "What is missing, in other words, are the very qualities that allow a human being to live in social harmony".

According to Hare, many psychopaths are superficially charming, and can excellently mimic normal human emotion; some psychopaths can blend in, undetected, in a variety of surroundings, including corporate environments.

Impulsiveness, irresponsibility and lack of foresight

Their behavior is impulsive and irresponsible. Psychopaths also have a markedly distorted sense of the potential consequences of their actions, not only for others, but also for themselves. They do not deeply recognize the risk of being caught, disbelieved or injured as a result of their behavior. Their behavior does not reform in response to punishment; they will impulsively commit crimes despite knowing the consequences they will likely face. They are among the worst of repeat offenders.

Psychopaths often claim to have ambitious goals in life but fail to appreciate the work, skill and discipline it would take to achieve them. Hare writes of one psychopathic inmate who planned to become a professional swimmer after release, despite the fact he was in his late thirties and overweight.

Perceptual/emotional recognition deficits

Facial affect recognition

In a 2002 study, David Kosson and Yana Suchy, et al. asked psychopathic inmates to name the emotion expressed on each of 30 faces. Compared to the control group, psychopaths had a significantly lower rate of accuracy in recognizing disgusted facial affect but a higher rate of accuracy in recognizing anger. Additionally, when "conditions designed to minimize the involvement of right-hemispheric mechanisms" (i.e., sadness) were used, psychopaths had more difficulty accurately identifying emotions. This study did not replicate Blair, et al. (1997)'s findings that psychopaths are specifically less sensitive to nonverbal cues of fear or distress.

Vocal affect recognition

In a 2002 experiment, Blair, Mitchell, et al. used the Vocal Affect Recognition Test to measure psychopaths' recognition of the emotional intonation given to connotative neutral words. Psychopaths tended to make more recognition errors than controls with a particularly high rate of error for sad and fearful vocal affect.

Stroop tasks

A 2004 experiment tested the hypothesis of over selective attention in psychopaths using two forms of the Stroop color-word and picture-word tasks: with color/picture and word separated and with color/picture and word together. Psychopaths performed significantly better than controls in the separated Stroop tasks, demonstrating less Stroop interference, and performed as well as the controls on standard Stroop tasks.

When split into low-anxious and high-anxious groups, low-anxious psychopaths and low-anxious controls showed less interference on the separated Stroop tasks than their high-anxious counterparts; for low-anxious psychopaths, interference was very nearly zero. Researchers concluded the inability to integrate contextual cues depends on the cues' relationship to "the deliberately attended, goal-relevant information."

Intelligence

Hare and Neumann (2008) states that there is at most a only a weak association between psychopathy and IQ. "Moreover, 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."

Causes and pathophysiology

One twin study suggests that psychopathy has a strong genetic component. The study demonstrates that children with anti-social behavior can be classified into two groups: those who were also callous acquired their behavior by genetic influences, and those who were not callous acquired it from their environment.

Neuranatomy

"The amygdala is crucial for stimulus-reinforcement learning and responding to emotional expressions, particularly fearful expressions that, as reinforcers, are important initiators of stimulus-reinforcement learning. Moreover, the amygdala is involved in the formation of both stimulus-punishment and stimulus-reward associations. Individuals with psychopathy show impairment in stimulus-reinforcement learning (whether punishment or reward based) and responding to fearful and sad expressions. It is argued that this impairment drives much of the syndrome of psychopathy (Blair, 2008).

People scoring ≥25 in the Psychopathy Checklist Revised, with an associated history of violent behavior, appear to have significantly reduced microstructural integrity in their uncinate fasciculuswhite matter connecting the amygdala and orbitofrontal cortex. The more extreme the psychopathy, the greater the abnormality.

Recent studies have triggered theories on determining whether there is a biological relationship between the brain and psychopathy. One theory suggests that psychopathy is associated with both the amygdala, which is associated with emotional reactions and emotion learning, and the prefrontal cortex, associated with impulse control, decision-making, emotional learning and behavioral adaptation. Some studies have shown there is less "gray matter" in these areas in psychopaths than in non-psychopaths.

There is DT-MRI evidence of breakdowns in the white matter connections between these two important areas in a small British study of nine criminal psychopaths. This evidence suggests that the degree of abnormality was significantly related to the degree of psychopathy and may explain the offending behaviors.

A 2008 review found various abnormalities (based on group differences from average) reported in the literature, centred on a prefrontal-temporo-limbic circuit — regions that are involved in emotional and learning processes, as well as many other processes. However, the authors report that the people classed as "psychopathic" cannot in fact be seen as a homogeneous group (i.e. as all having the same characteristics), and that the associations between structural changes and psychopathic characteristics do not enable causal conclusions to be drawn. They conclude that psychopathic characteristics involve multifactorial processes including neurobiological, genetic, epidemiological, and sociobiographical (the person's life in society) factors.

Neurotransmitters and hormones

High levels of testosterone combined with low levels of cortisol have been theorized as contributing factors. Testosterone is "associated with approach-related behavior, reward sensitivity, and fear reduction". Cortisol increases "the state of fear, sensitivity to punishment, and withdrawal behavior". Injecting testosterone "shift the balance from punishment to reward sensitivity", decreases fearfulness, and increases "responding to angry faces". Some studies have found that antisocial and aggressive behaviors are associated with high testosterone levels but it is unclear if psychopaths have high testosterone levels. A few studies have found psychopathy to be linked to low cortisol levels.

High testosterone levels combined with low serotonin levels may increase violent aggression. Some research suggests that testosterone alone does not cause aggression but increases dominance seeking-behaviors. Low serotonin is associated with "impulsive and highly-negative reactions" which if combined with high testosterone may cause aggression if an individual becomes frustrated.

Psychopathy was also associated in two studies with an increased ratio of HVA (a dopamine metabolite) to 5-HIAA (a serotonin metabolite).

Diagnosis

Currently, there are no diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders for psychopathy. Labeling a person as a psychopath involves forensic measurement, using a diagnostic tool such as the Hare Psychopathy Checklist (PCL-R). The PCL-R is widely considered the "gold standard" for assessing psychopathy. Psychopathy is most strongly correlated with DSM-IV antisocial personality disorder (ASPD), and the ICD-10 antisocial personality disorder and dissocial personality disorder (DPD). However, the PCL-R criteria for identifying a psychopath are stricter than the diagnostic criteria for ASPD or DPD; psychopaths represent a subset of those with ASPD, and psychopaths' traits are more severe.

One issue related to the assessment of individuals who may exhibit affective, interpersonal, and behavioral features associated with psychopathy is the ability to overcome gender myths when the psychopathy features are present in females. The Hare Psychopathy Checklist-Revised has both percentiles and T-score tables for male and female offenders.

Cleckley Checklist

In his 1941 book, Mask of Sanity, Hervey M. Cleckley introduced 16 behavioral characteristics of a psychopath:

  1. Superficial charm and good "intelligence"
  2. Absence of delusions and other signs of irrational thinking
  3. Absence of nervousness or psychoneurotic manifestations
  4. Unreliability
  5. Untruthfulness and insincerity
  6. Lack of remorse and shame
  7. Inadequately motivated antisocial behavior
  8. Poor judgment and failure to learn by experience
  9. Pathologic egocentricity and incapacity for love
  10. General poverty in major affective reactions
  11. Specific loss of insight
  12. Unresponsiveness in general interpersonal relations
  13. Fantastic and uninviting behavior with drink and sometimes without
  14. Suicide threats rarely carried out
  15. Sex life impersonal, trivial, and poorly integrated
  16. Failure to follow any life plan.

Hare Psychopathy Checklist

Main article: Hare Psychopathy Checklist

Psychopathy is most commonly assessed with the PCL-R, which is a clinical rating scale with 20 items. Each of the items in the PCL-R is scored on a three-point (0, 1, 2) scale according to two factors. PCL-R Factor 2 is associated with behavioral deficits or antisocial lifestyle, more specifically: reactive anger, anxiety, increased risk of suicide, criminality, and impulsive violence.

PCL-R Factor 1, in contrast, is associated with personality deficits or aggressive narcissism, more specifically: extraversion and positive affect. Factor 1, the so-called core personality traits of psychopathy, may even be beneficial for the psychopath (in terms of non‑deviant social functioning). A psychopath will score high on both factors, whereas someone with ASPD will score high only on Factor 2. Both case history and a semi-structured interview are used in the analysis.

Because an individual's scores may have important consequences for his or her future, the potential for harm if the test is used or administered incorrectly is considerable. The test can only be considered valid if administered by a suitably qualified and experienced clinician under controlled conditions.

PCL-R items

The following findings are for research purposes only, and are not used in clinical diagnosis. These items cover the affective, interpersonal, and behavioral features. Each item is rated on a score from zero to two. The sum total determines the extent of a person's psychopathy.

Factor 1
Aggressive narcissism
  1. Glibness/superficial charm
  2. Grandiose sense of self-worth
  3. Pathological lying
  4. Cunning/manipulative
  5. Lack of remorse or guilt
  6. Emotionally shallow
  7. Callous/lack of empathy
  8. Failure to accept responsibility for own actions
Factor 2
Socially deviant lifestyle
  1. Need for stimulation/proneness to boredom
  2. Parasitic lifestyle
  3. Poor behavioral control
  4. Promiscuous sexual behavior
  5. Lack of realistic, long-term goals
  6. Impulsiveness
  7. Irresponsibility
  8. Juvenile delinquency
  9. Early behavioral problems
  10. Revocation of conditional release
Traits not correlated with either factor
  1. Many short-term marital relationships
  2. Criminal versatility

Comorbidity

Psychopaths may have various mental conditions, although, in contrast to people with antisocial personality disorder, comorbidity among psychopaths is generally found to be low.

Substance abuse has been associated with psychopathy, particularly Factor 2 (anti-social behaviour), but not Factor 1 (emotional) scores of the PCL-R. Conduct disorder and ADHD have both been associated with psychopathy; which may be explained by disruption to dorsolateral prefrontal cortex. This area is associated with executive function, which is affected in all three disorders.

There is some evidence of an association between ASPD and other personality disorders (i.e. histrionic, narcissistic and borderline personality disorders), however, evidence for a link with psychopathy is more tentative.

Anxiety may be associated positively with antisocial behaviour, but it is inversely associated with Factor I (emotional) scores on the PCL-R. Depression is inversely associated with psychopathy. Although violence may be associated with schizophrenia, there is no conclusive evidence for a link between psychopathy and schizophrenia.

It has been suggested that psychopathy may be comorbid with several other diagnoses than these, however limited work on comorbidity has been carried out. This may be because of difficulties in using inpatient groups from certain institutions to assess comorbidity, owing to the likelihood of some bias in sample selection. Furthermore, comorbidity may be more reflective of poor discriminant validity of categories in the DSM-IV than reflective of underlying aetiologically separate conditions.


Psychopathy and Sexual Deviance

Sexual preferences are usually considered deviant when they stray statistically from the norm and, when acted on, tend to inflict unwanted harm on oneself or others (Lalumière & Quinsey, 1999). In a study conducted by Barbaree et al. (1994) using Penile Plethysmography, psychopaths showed more increased penile blood flow than did controls upon being shown deviant visual and auditory stimuli. This may be due to the psychopath’s complete disregard for social norms and lack of attachment to others. The desire to be socially accepted is so deeply ingrained into the minds and personalities of average humans, that to some extent this dictates our sexual feelings. While the psychopath will attempt to blend in, their undisclosed desires are completely uninhibited by social standards. There is also evidence to suggest that psychopathic sexual offenders use more violence against their victims than do nonpsychopathic sexual offenders, suggesting that the psychopath may have a higher propensity to be sexually sadistic. Woodworth et al. (2003) examined the correlation between PCL-R scores and types of aggression expressed in a sample of 38 sexual murderers. 84.7% of these individuals scored in the moderate to high range (scores significantly higher than those of a group of nonsexual murderers). Also, murders committed by psychopaths (those with a score of 20 or above) showed more gratuitous and sadistic violence than those of nonpsychopaths. 82.4% of psychopaths committed sadistic violence against their victims, compared to only 52.6% of nonpsychopaths.

Conceptual models

As a discrete disorder

Hare believes that the Diagnostic and Statistical Manual of Mental Disorders should list psychopathy as a unique disorder, given that psychopathy has no precise equivalent in either the DSM-IV-TR, where it is most strongly correlated with the diagnosis of antisocial personality disorder, or the ICD-10, which has a partly similar condition called dissocial personality disorder.

Primary-secondary distinction

Primary psychopathy was defined by those following this theory as the root disorder in patients diagnosed with it, whereas secondary psychopathy was defined as an aspect of another psychiatric disorder or social circumstances. Today, primary psychopaths are considered to have mostly Factor 1 traits from the PCL-R (arrogance, callousness, manipulativeness, lying) whereas secondary psychopaths have a majority of Factor 2 traits (impulsivity, boredom proneness, irresponsibility, lack of long-term goals).

The primary psychopath engages in antisocial behavior as a result of a genetic-biological predisposition directed by particular psychodynamic forces that occur in infancy. The secondary psychopath's antisocial behavior is the result of strictly environmental forces (e.g., membership in a deviant group) that occur at developmental stages beyond infancy. The fundamental distinction between the two is the ability to attach emotionally to others and to experience the natural anxiety associated with human attachment. The primary psychopath forms no attachments as a result of early developmental obstruction, and thus is capable of harming others with little or no anxiety. The secondary psychopath forms human attachments, possibly to deviant subgroups, or not. However, whether or not the secondary psychopath appears to be attached to others, emotional connection to other human beings is present.

Secondary psychopaths show normal to above-normal physiological responses to (perceived) potential threats; their crimes tend to be unplanned and impulsive with little thought of the consequences. According to those using this theory, this type have hot tempers and are prone to reactive aggression. They experience normal to above-normal levels of anxiety but are nevertheless highly stimulus-seeking and have trouble tolerating boredom. Their lifestyle may lead to depression and even suicide.

Mealey uses the term "primary psychopathy" to differentiate between psychopathy that is biological in origin and "secondary psychopathy" that results from a combination of genetic and environmental influences. Lykken prefers sociopathy to describe the latter.

Sellbom and Ben-Porath (2005) describe the distinction:

Some people who engage in violent behavior possess psychopathic personality traits, such as callousness, grandiosity, and fearlessness, and presumably engage in such conduct because they care little about others. Others are impulsive and experience considerable anger, anxiety, and distress and may commit violent acts as a reaction to negative emotions, which are sometimes referred to as "crimes of passion." Indeed, the distinction between primary and secondary psychopathy (including so-called neurotic psychopathy) has long been noted in the psychopathy literature (Karpman, 1947; Lykken, 1995).

This distinction closely resembles the distinction between instrumental and impulsive/reactive crime/violence in the field of criminology.

Joseph P. Newman et al., who use this concept of psychopathy, have validated David T. Lykken's conceptualization of psychopathy subtypes in relation to Gray's behavioral activation system and behavioral inhibition system. Newman et al. found measures of primary psychopathy to be negatively correlated with Gray's behavioral inhibition system, a construct intended to measure behavioral inhibition from cues of punishment or nonreward. In contrast, measures of secondary psychopathy to be positively correlated with Gray's behavioral activation system, a construct intended to measure sensitivity to cues of behavioral approach.

Psychopathy vs. sociopathy

Hare writes that the difference between sociopathy and psychopathy may "reflect the user's views on the origins and determinates of the disorder."

In the preface to the fifth edition of The Mask of Sanity, Cleckly stated, "... revisions of the nomenclature have been made by the American Psychiatric Association. The classification of psychopathic personality was changed to that of sociopathic personality in 1958", suggesting that he did not recognise any difference between the conditions.

David T. Lykken proposes psychopathy and sociopathy are two distinct kinds of antisocial personality disorder. He believes psychopaths are born with temperamental differences such as impulsivity, cortical underarousal, and fearlessness that lead them to risk-seeking behavior and an inability to internalize social norms. On the other hand, he claims sociopaths have relatively normal temperaments; their personality disorder being more an effect of negative sociological factors like parental neglect, delinquent peers, poverty, and extremely low or extremely high intelligence. Both personality disorders are the result of an interaction between genetic predispositions and environmental factors, but psychopathy leans towards the hereditary whereas sociopathy tends towards the environmental.

Three-factor model

Recent statistical analysis using confirmatory factor analysis by Cooke and Michie indicated a three-factor structure, with those items from factor 2 strictly relating to antisocial behaviour (criminal versatility, juvenile delinquency, revocation of conditional release, early behavioural problems, and poor behavioural controls) removed from the final model. The remaining items are divided into three factors: Arrogant and Deceitful Interpersonal Style, Deficient Affective Experience, and Impulsive and Irresponsible Behavioural Style.

Hare and colleagues have published detailed critiques of the Cooke & Michie hierarchical ‘three’-factor model, citing severe statistical problems. Hare and colleagues note that the Cooke & Michie model actually contains ten factors, and results in impossible parameters (negative variances). Hare and colleagues also note conceptual problems with this model.

Discrete vs. continuous

As part of the larger debate on whether personality disorders are distinct from normal personality, or if they are extremes on various dimensions of normal personality, is the debate on whether psychopathy represents something "qualitatively different" from normal personality, or a "continuous dimension" shading from normality into severely psychopathic. Otto Kernberg believed psychopathy should fall under a spectrum of pathological narcissism, that ranged from narcissistic personality on the low end, malignant narcissism in the middle, and psychopathy at the high end.

Early taxonometric analysis from Harris and colleagues indicated a discrete category may underlie psychopathy, but this was only found for the behavioural Factor 2 items, indicating this analysis may be related to Antisocial Personality Disorder rather than psychopathy per se. Marcus, John, and Edens more recently performed a series of statistical analysis on previously attained PCL–R and PPI scores and concluded psychopathy may best be conceptualized as having a "dimensional latent structure" like depression.

Screening

Childhood precursors

Psychopathic tendencies can sometimes be recognized in childhood or early adolescence. If recognized, a diagnosis of Conduct Disorder, or possibly the related Oppositional Defiant Disorder, may be given. However, while these childhood signs have been found in a significantly higher proportion of psychopaths than in the general population, it must be stressed that not all the subjects of such childhood diagnoses turn out to be psychopaths as adults, or even disordered at all. Therefore, psychopathy is not normally diagnosed in children or adolescents, and some jurisdictions explicitly forbid diagnosing minors with psychopathy and similar personality disorders. This is because such a diagnosis "fails to capture the emotional, cognitive, and interpersonality traits — egocentricity and lack of remorse, empathy, or guilt - that are so important in the diagnosis of psychopathy."

Children showing strong psychopathic precursors often appear immune to punishment; nothing seems to modify their undesirable behavior. Consequently parents usually give up, and the behavior worsens.

The following childhood indicators are to be seen not as to the type of behavior, but as to its relentless and unvarying occurrence. Not all must be present concurrently, but at least a number of them need to be present over a period of years. These indicators are sufficient - but not necessary - indicators of possible psychopathy.

  • An extended period of bedwetting past the preschool years, not due to any medical problem.
  • Precocious sadism, often expressed as profound animal abuse.
  • Pathological firesetting, lacking in obvious homicidal intent. Not to be confused with playing with matches, which is not uncommon for preschoolers. This is the deliberate setting of destructive fires with utter disregard for the property and lives of others.
  • Lying, often without discernible objectives, extending beyond a child's normal impulse not to be punished. These lies are so extensive it is often impossible to know lies from truth.
  • Theft and truancy.
  • Aggression towards peers and relatives. The aggression can include physical and verbal abuse, getting others into trouble, or a campaign of psychological torment.

The three indicators — bedwetting, cruelty to animals and firestarting, known as the Macdonald triad — were first described by J.M. MacDonald as "red flag" indicators of psychopathy and future episodic aggressive behavior. However, subsequent research has found that bedwetting is not a significant factor. The question of whether young children with early indicators of psychopathy respond poorly to intervention, compared to conduct-disordered children without these traits, has only recently been examined in controlled clinical research. The empirical findings from this research have been consistent with broader anecdotal evidence, pointing to poor treatment outcomes.

Prenatal precursors

File:Richard Loeb.jpg
The modified dimorphic features of infamous thrill killer Richard Loeb.

Although the research is still in its infancy, some recent evidence has emerged that suggest high doses of prenatal estrogen exposure might exacerbate a predisposition to psychopathy, especially in males. A 2010 British study, utilizing the digit ratio, concluded that there is in fact a phenotypic marker to support this theory. It is thought that larger doses of in-utero estrogen exposure may inhibit hemespheric brain specialization , and hinder connections to the prefrontal cortex, which is usually associated with impulse control. Other phenotypic and cognitive outcomes of substantial prenatal estrogen exposure, especially in males, could be a more feminine appearance (which is usually perceived as less threatening to both men and women) and thus may give a psychopath an even greater edge in psychological deception, in addition to greater verbal abilities. Regardless, more research is needed in this biological field to help psychologist and law enforcement identify, detect and solve the enigma of psychopathy.

Management

Clinical management

In practice, mental health professionals rarely treat psychopathic personality disorders as they are often considered untreatable and no interventions have proved to be effective. However, some of the difficulty has been attributed to the lack of clarity about the concept and diagnosis of psychopathy; the threat of danger to staff, or deceit or poor motivation from patients; and a lack of follow-up to test effectiveness. Despite pessimism, as of 1999, treatment of patients still takes place in a variety of psychiatric hospitals and secure units, and the research has indicated that some individuals do show some improvements when the right treatment is identified, and that longer periods of therapy often produce better results.

It has been shown that punishment and behavior modification techniques do not improve the behavior of psychopaths. Psychopathic individuals have been regularly observed to become more cunning and better able to hide their behaviour. It has been suggested that traditional therapeutic approaches actually make psychopaths more adept at manipulating others and concealing their behavior. They are generally considered to be not only incurable but also untreatable.

However, some researchers suggest that psychopaths can benefit as much as others from psychological treatment, at least in terms of criminal behaviors. For example, one therapeutic approach to juveniles reports reduced re-offending over a two year period compared to usual care.

Legal response

United Kingdom

In the United Kingdom, "Psychopathic Disorder" was legally defined in the Mental Health Act (UK) as, "a persistent disorder or disability of mind (whether or not including significant impairment of intelligence) which results in abnormally aggressive or seriously irresponsible conduct on the part of the person concerned." This term, which did not equate to psychopathy, was intended to reflect the presence of a personality disorder, in terms of conditions for detention under the Mental Health Act 1983. With the subsequent amendments to the Mental Health Act 1983 within the Mental Health Act 2007, the term 'psychopathic disorder' has been abolished, with all conditions for detention (e.g. mental illness, personality disorder, etc.) now being contained within the generic term of 'mental disorder'.

A 1997 study by the University of Warwick found that, where the severity of a patient's condition was not likely to "cause a potential risk to the safety of the greater community", the patients were encouraged to obtain PSV licenses for therapeutic purposes. After consultation with the Department of Transport, it was decided to offer financial incentives to public transport service operators to employ the rehabilitated patients. This was most successful in Bristol and Sheffield as the scheme was taken up in these areas by the FirstGroup company, a large public transport provider in th UK.

In England and Wales, the diagnosis of dissocial personality disorder is grounds for detention in secure psychiatric hospitals under the Mental Health Act if they have committed serious crimes, but since such individuals are disruptive for other patients and not responsive to treatment this alternative to prison is not often used.

United States

Psychopathy has quite separate legal and judicial definitions that should not be confused with the medical definition. The American Psychiatric Association is vigorously opposing any non-medical or legal definition of what purports to be a medical condition "without regard for scientific and clinical knowledge." Various states and nations have at various times enacted laws specific to dealing with psychopaths.

In the United States, approximately 20 states currently have provisions for the involuntary civil commitment for sex offenders or sexual predators, under Sexually violent predator acts, avoiding the use of the term "psychopath." These statutes and provisions are controversial and are being reviewed by the U.S. Supreme Court as a violation of a person's Fourteenth Amendment rights. (See Foucha v. Louisiana for an example.)

Washington

Washington State Legislature defines a "Psychopathic personality" to mean "the existence in any person of such hereditary, congenital or acquired condition affecting the emotional or volitional rather than the intellectual field and manifested by anomalies of such character as to render satisfactory social adjustment of such person difficult or impossible." The same statute defines the "sexual psychopath" as "any person who is affected in a form of psychoneurosis or in a form of psychopathic personality, which form predisposes such person to the commission of sexual offenses in a degree constituting him a menace to the health or safety of others" for prison sentencing purposes in the Sentencing Reform Act of 1981.

California

California enacted a psychopathic offender law in 1939, since greatly outmoded and revised, that defined a psychopath solely in terms of offenders with a predisposition "to the commission of sexual offenses against children." A 1941 law attempted to further clarify this to the point where anyone examined and found to be psychopathic was to be committed to a state hospital and anyone else was to be sentenced by the courts. However, these laws were enacted years before the American Psychiatric Association began publishing the Diagnostic and Statistical Manual of Mental Disorders which is used today for diagnosis and does not include "psychopathic offender". Hence, these laws are of historical interest only.

Prognosis

Release rate among convicted criminals

Psychopathy was associated with more violent and non-violent, but not sexual, offences. A significant interaction between psychopathy and offender subtype revealed that psychopathy was associated with a greater number of sex offences within child molesters. High-psychopathy offenders (both sexual and non-sexual offenders) were about 2.5 times more likely to be granted conditional release than non-psychopathic offenders.

Epidemiology

It is estimated that approximately one percent of the general population are psychopaths. According to an unsourced article in popular science magazine Scientific American, studies indicate that about 25% of prison inmates meet diagnostic criteria for psychopathy. However, recent British studies have reported a community prevalence of 0.6%, consistent with the estimate given by the screening version of the psychopathy checklist and a prisoner prevalence of 7.7% in men and 1.9% in women.

History

The current concept of psychopathy has been thematically linked to writings by Theophrastus, a student of Aristotle in Ancient Greece, whose description of The Unscrupulous Man is said to embody the characteristics of psychopathy:

"The Unscrupulous Man will go and borrow more money from a creditor he has never paid ... When marketing he reminds the butcher of some service he has rendered him and, standing near the scales, throws in some meat, if he can, and a soup-bone. If he succeeds, so much the better; if not, he will snatch a piece of tripe and go off laughing."

In 1801, Philippe Pinel described patients who were mentally unimpaired but nonetheless engaged in impulsive and self-defeating acts. He saw them as la folie raisonnante ("insane without delirium") meaning they fully understood the irrationality of their behavior but continued with it anyway.

The scientific study of individuals thought to lack a conscience flourished in the latter half of the 19th century. Notably, Cesare Lombroso rejected the view that criminality could occur in anyone and instead sought to identify particular "born criminals" whom he thought showed certain physical defects.

By the turn of the 20th century, Henry Maudsley had begun writing about the "moral imbecile", and was arguing such individuals could not be rehabilitated by the correctional system. Maudsley included the psychopath's immunity to the reformational effects of punishment, owing to their refusal to anticipate further failure, and punishment. In 1904, Emil Kraepelin described four types of personalities similar to antisocial personality disorder. By 1915 he had identified them as defective in either affect or volition, dividing the types further into different categories, only some of which correspond to the current descriptions of antisocial personality disorder.

In 1909, Birnbaum introduced the term "sociopathic", intended to emphasize the social causes of antisocial behavior.

The Mask of Sanity by Hervey M. Cleckley, M.D., first published in 1941, is considered a seminal work which provided a vivid series of case studies of individuals (mostly prisoners) described by Cleckley as psychopathic. Cleckley proposed 16 characteristics of psychopathy. The title refers to the "mask" of normality that Cleckley thought concealed the disorganization or mental disorder of what he saw as the psychopathic person.

A 1977 study, however, found little relationship with the characteristics commonly attributed to psychopaths and concluded that the concept was being used too widely and loosely.

The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders incorporated various concepts of psychopathy/sociopathy/antisocial personality in early versions but, starting with the DSM-III in 1980, used instead a diagnosis of antisocial personality disorder. This was based on some of the criteria put forward by Cleckley but operationalized in behavioral terms and more specifically related to conduct and criminality. The World Health Organization's ICD incorporates a similar diagnosis of Dissocial Personality Disorder. Both the DSM and the ICD state that psychopathy (or sociopathy) are synonyms of their diagnosis.

However, there remained no international agreement on the diagnosis of psychopathy. One author referred to it in 1987 as an "infinitely elastic, catch-all category". In 1988, Blackburn wrote in the British Journal of Psychiatry that the concept as commonly used in psychiatry is little more than a moral judgement masquerading as a clinical diagnosis, and argued that it should be scrapped.

Robert Hare developed a Psychopathy Checklist in 1980 based on the psychopath construct advanced by Cleckley, and later revised it in the 1990s (including the removal of two items). While the official diagnostic manuals had moved away from the concept as being too vague and difficult to reliably assess, Hare's questionnaire would be increasingly used in research studies on psychopathy mainly in forensic (criminal) settings.

In other animals

Several studies note the role of serotonergic functioning in impulsive aggression and antisocial behavior in animals.

See also

References

Notes

  1. American Heritage Dictionary
  2. Merriam-Webster's Online Dictionary
  3. Helfgott, J. B. (2000) CRJS 450: The Psychopath . Retrieved from http://jhelfgott.pageout.net/page.dyn/student/course/course_home?course_id=63357
  4. http://www.psychiatrictimes.com/dsm-iv/content/article/10168/54831
  5. "Proposed revision" (Document). DSM5Template:Inconsistent citations {{cite document}}: Unknown parameter |url= ignored (help)CS1 maint: postscript (link).
  6. http://www.mentalhealth.com/icd/p22-pe04.html
  7. Patrick, Christopher J. Handbook of Psychopathy
  8. ^ Harris, Grant; Rice, Marnie (2006). Patrick, Christopher (ed.). "Handbook of Psychopathy": 555–72. {{cite journal}}: |contribution= ignored (help); Cite journal requires |journal= (help)
  9. ^ "What "Psychopath" Means". Scientific American.
  10. ^ Hare, Robert D. Without Conscience: The Disturbing World of Psychopaths Among Us, (New York: Pocket Books, 1993)
  11. ^ Weber S, Habel U, Amunts K, Schneider F (2008). "Structural brain abnormalities in psychopaths-a review". Behavioral Sciences & the Law. 26 (1): 7–28. doi:10.1002/bsl.802. PMID 18327824.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  12. ^ Neumann, Craig S.; Hare, Robert D. (2008). "Psychopathic traits in a large community sample: Links to violence, alcohol use, and intelligence". Journal of Consulting and Clinical Psychology. 76 (5): 893–9. doi:10.1037/0022-006X.76.5.893. PMID 18837606. A summary of one of Hare's books
  13. Helfgott, J. B. (2000) CRJS 450: The Psychopath . Retrieved from http://jhelfgott.pageout.net/page.dyn/student/course/course_home?course_id=63357
  14. Jill S. Levenson, John W. Morin (2000) p. 7 SAGE, ISBN 0761921923
  15. Marvin Zuckerman (1991) Psychobiology of personality Cambridge University Press, p. 390. ISBN 0521359422
  16. Glenn D. Walters (2006) Lifestyle theory p. 42 Nova Publishers, ISBN 1600210333
  17. "Psychopathic personality". Dictionary.com. Retrieved 25 April 2011.
  18. ^ Millon, Theodore; Davis, Roger D. "Chapter 11: The Five-Factor Model of Personality, pp. 173-177. Psychopathy: Antisocial, Criminal, and Violent Behavior.
  19. Ochberg FM, Brantley AC, Hare RD; et al. (2003). "Lethal predators: psychopathic, sadistic, and sane". International Journal of Emergency Mental Health. 5 (3): 121–36. PMID 14608825. {{cite journal}}: Explicit use of et al. in: |author= (help)CS1 maint: multiple names: authors list (link)
  20. Simon, R. I. Psychopaths, the predators among us. In R. I. Simon (Ed.) Bad Men Do What Good Men Dream (pp. 21-46). Washington: American Psychiatric Publishing, Inc.1996
  21. E. Forth, Adelle; Cooke, David C.; Hare, Robert R. (1998). Psychopathy: theory, research and implications for society. Dordrecht: Kluwer Academic. ISBN 0-7923-4919-9.
  22. Heilbrun, Kirk (2003). "Violence Risk: From Prediction to Management": 127. doi:10.1002/0470013397.ch5. {{cite journal}}: Cite journal requires |journal= (help)
  23. Harris, G. T.; Rice, M. E.; Lalumiere, M. (2001). "Criminal Violence: The Roles of Psychopathy, Neurodevelopmental Insults, and Antisocial Parenting". Criminal Justice and Behavior. 28 (4): 402. doi:10.1177/009385480102800402.
  24. ^ Hare, Robert D, Psychopaths: New Trends in Research. The Harvard Mental Health Letter, September 1995 Cite error: The named reference "hare2" was defined multiple times with different content (see the help page).
  25. Hare, Robert D. Without Conscience: The Disturbing World of Psychopaths Among Us, (New York: Pocket Books, 1993) pg 2.
  26. Hare, Robert D with Paul Babiak Snakes in Suits: When Psychopaths Go to Work (2006)
  27. Dadds, M. R.; Perry, Y; Hawes, DJ; Merz, S; Riddell, AC; Haines, DJ; Solak, E; Abeygunawardane, AI (2006). "Attention to the eyes and fear-recognition deficits in child psychopathy". The British Journal of Psychiatry. 189 (3): 280–1. doi:10.1192/bjp.bp.105.018150. PMID 16946366.
  28. Hare. Without Conscience. pg 40
  29. Kosson DS, Suchy Y, Mayer AR, Libby J (2002). "Facial affect recognition in criminal psychopaths". Emotion. 2 (4): 398–411. doi:10.1037/1528-3542.2.4.398. PMID 12899372. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  30. Blair RJ, Mitchell DG, Richell RA; et al. (2002). "Turning a deaf ear to fear: impaired recognition of vocal affect in psychopathic individuals". Journal of Abnormal Psychology. 111 (4): 682–6. doi:10.1037/0021-843X.111.4.682. PMID 12428783. {{cite journal}}: Explicit use of et al. in: |author= (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  31. Hiatt KD, Schmitt WA, Newman JP (2004). "Stroop tasks reveal abnormal selective attention among psychopathic offenders". Neuropsychology. 18 (1): 50–9. doi:10.1037/0894-4105.18.1.50. PMID 14744187. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  32. Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1146/annurev.clinpsy.3.022806.091452, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.1146/annurev.clinpsy.3.022806.091452 instead.
  33. Viding, Essi; Blair, R. James R.; Moffitt, Terrie E.; Plomin, Robert (2005). "Evidence for substantial genetic risk for psychopathy in 7-year-olds". Journal of Child Psychology and Psychiatry. 46 (6): 592–7. doi:10.1111/j.1469-7610.2004.00393.x. PMID 15877765.
  34. Blair, RJ (23 April 2008). "The amygdala and ventromedial prefrontal cortex: functional contributions and dysfunction in psychopathy". Philosophical Transactions of the Royal Society. 363 (1503): 2557–2565. doi:10.1098/rstb.2008.0027. PMC 2606709. PMID 18434283.
  35. Craig, Michael C (2009-06-09). "Altered connections on the road to psychopathy". Molecular Psychiatry. 14 (10): 946–53, 907. doi:10.1038/mp.2009.40. PMID 19506560. Retrieved 2010-07-20. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |laysource= ignored (help); Unknown parameter |laysummary= ignored (help)
  36. Weber, Sabrina; Habel, Ute; Amunts, Katrin; Schneider, Frank (2008). "Structural brain abnormalities in psychopaths—a review". Behavioral Sciences & the Law. 26 (1): 7–28. doi:10.1002/bsl.802. PMID 18327824.
  37. Craig, M C; Catani, M; Deeley, Q; Latham, R; Daly, E; Kanaan, R; Picchioni, M; McGuire, P K; Fahy, T (2009). "Altered connections on the road to psychopathy". Molecular Psychiatry. 14 (10): 946–53, 907. doi:10.1038/mp.2009.40. PMID 19506560.
  38. Craig MC, Catani M, Deeley Q; et al. (2009). "Altered connections on the road to psychopathy". Molecular Psychiatry. 14 (10): 946–53, 907. doi:10.1038/mp.2009.40. PMID 19506560. {{cite journal}}: Explicit use of et al. in: |author= (help); Unknown parameter |laydate= ignored (help); Unknown parameter |laysource= ignored (help); Unknown parameter |laysummary= ignored (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  39. ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1016/j.psc.2008.03.004, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.1016/j.psc.2008.03.004 instead.
  40. ^ Semple, David (2005). The Oxford Handbook of Psychiatry. USA: Oxford University Press. pp. 448–449. ISBN 0-19-852783-7.
  41. Perri, Frank S.; Lichtenwald, Terrance G. (2010). "The Last Frontier: Myths & The Female Psychopathic Killer" (PDF). Forensic Examiner. 19 (2): 50–67.
  42. Cleckley, pp.338-339 (5th ed.)
  43. Hare, 1991
  44. Hare, R. (1993). Without Conscience. New York, NY: The Guilford Press.
  45. Hare, R. (1993). Without Conscience. New York, NY: The Guilford Press.
  46. Davison, G.C., Neale, J.M., Blankstein, K.R., & Flett, G.L. (2002). Abnormal Psychology. (Etobicoke: Wiley)
  47. ^ Hare, R. D. (2003). Manual for the Revised Psychopathy Checklist (2nd ed.). Toronto, ON, Canada: Multi-Health Systems. Cite error: The named reference "hare1" was defined multiple times with different content (see the help page).
  48. ^ Blair, J (2005). Psychopathy, emotion and the brain. Wiley-Blackwell. pp. 25–27. ISBN 0631233369. {{cite book}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)
  49. ^ Losel, Frederick (1997). "Treatment and management of psychopaths". In Cooke, DJ; Forth, AE; Hare, RD (eds.). Psychopathy: Theory, Research and Implications for Society (NATO Science Series D). Springer. p. 309. ISBN 0792349199.
  50. ^ Nedopil, N. "Comorbidity of psychopathy with major mental disorders". In Cooke, DJ; Forth, AE; Hare, RD (eds.). Psychopathy: Theory, Research and Implications for Society (NATO Science Series D). Springer. ISBN 0792349199. {{cite book}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)
  51. ^ Kantor, Martin (2006). The Psychopathy of Everyday Life. ISBN 0275987981.
  52. Karpman, B. (1948). "THE MYTH OF THE PSYCHOPATHIC PERSONALITY". American Journal of Psychiatry. 104 (9): 523–34. doi:10.1176/appi.ajp.104.9.523. PMID 18911629.
  53. ^ Lykken, David T. The Antisocial Personalities (1995).
  54. Helfgott, J. B. (2000) CRJS 450: The Psychopath . Retrieved from http://jhelfgott.pageout.net/page.dyn/student/course/course_home?course_id=63357
  55. ^ Cleckley, M.D., Hervey (1982). The Mask of Sanity (Revised ed.). Mosbey Medical Library. ISBN 0-452-25341-1. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)
  56. Mealey, L. (1995). The sociobiology of sociopathy: An integrated evolutionary model. Behavioral and Brain Sciences, 18, 523–559.
  57. Sellbom M, Ben-Porath YS, Lilienfeld SO, Patrick CJ, Graham JR (2005). "Assessing psychopathic personality traits with the MMPI-2". Journal of Personality Assessment. 85 (3): 334–43. doi:10.1207/s15327752jpa8503_10. PMID 16318573. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  58. ^ Newman JP, MacCoon DG, Vaughn LJ, Sadeh N (2005). "Validating a distinction between primary and secondary psychopathy with measures of Gray's BIS and BAS constructs". Journal of Abnormal Psychology. 114 (2): 319–23. doi:10.1037/0021-843X.114.2.319. PMID 15869363. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  59. Hare, Robert D. Without Conscience: The Disturbing World of Psychopaths Among Us, (New York: Pocket Books, 1993) pg 23.
  60. ^ Cooke, David J.; Michie, Christine (2001). "Refining the construct of psychopath: Towards a hierarchical model". Psychological Assessment. 13 (2): 171–88. doi:10.1037/1040-3590.13.2.171. PMID 11433793.
  61. Hare, Robert D.; Neumann, Craig S. (2008). "Psychopathy as a Clinical and Empirical Construct". Annual Review of Clinical Psychology. 4: 217–46. doi:10.1146/annurev.clinpsy.3.022806.091452. PMID 18370617.
  62. Otto F., Kernberg (2004). Aggressivity, Narcissism, and Self-Destructiveness in the Psychotherapeutic Relationship: New Developments in the Psychopathology and Psychotherapy of Severe Personality Disorders. Yale University Press. ISBN 0-300-10180-5.
  63. Harris GT, Rice ME, Quinsey VL (1994). "Psychopathy as a taxon: evidence that psychopaths are a discrete class". Journal of Consulting and Clinical Psychology. 62 (2): 387–97. doi:10.1037/0022-006X.62.2.387. PMID 8201078. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  64. Marcus DK, John SL, Edens JF (2004). "A taxometric analysis of psychopathic personality". Journal of Abnormal Psychology. 113 (4): 626–35. doi:10.1037/0021-843X.113.4.626. PMID 15535794. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  65. Hare, Robert D. Without Conscience: The Disturbing World of Psychopaths Among Us, (New York: Pocket Books, 1993) pg 159.
  66. Ramsland, Katherine, The Childhood Psychopath: Bad Seed or Bad Parents?
  67. McClellan, Janet (2007). "Animal Cruelty and Violent Behavior: Is There a Connection?". Journal of Security Education. 2 (4): 29–45. doi:10.1300/J460v02n04_04. {{cite journal}}: Unknown parameter |doi_brokendate= ignored (|doi-broken-date= suggested) (help); Unknown parameter |month= ignored (help)
  68. J. M. MacDonald (1963). "The Threat to Kill". American Journal of Psychiatry. 120 (2): 125–130.
  69. Weatherby, G. A.; Buller, D. M.; McGinnis, K. (2009). "The Buller-McGinnis model of serial-homicidal behavior: An integrated approach" (PDF). Journal of Criminology and Criminal Justice Research and Education. 3: 1.
  70. Hawes DJ, Dadds MR (2005). "The treatment of conduct problems in children with callous-unemotional traits". Journal of Consulting and Clinical Psychology. 73 (4): 737–41. doi:10.1037/0022-006X.73.4.737. PMID 16173862. {{cite journal}}: Unknown parameter |month= ignored (help)
  71. Blanchard, A. (2010). "An Investigation into the Relationship between Digit Length Ratio and Psychopathy". British Journal of Forensic Practice. 12 (2). {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)
  72. Reinisch JM, Sanders SA (1992). "Effects of prenatal exposure to diethylstilbestrol (DES) on hemispheric laterality and spatial ability in human males". Horm Behav. 26 (1): 62–75. PMID 1563729. {{cite journal}}: Unknown parameter |month= ignored (help)
  73. "Prenatal Testosteron makes a Genius?". The World of Science and Technology.
  74. Neave N, Laing S, Fink B, Manning JT (2003). "Second to fourth digit ratio, testosterone and perceived male dominance". Proceedings. Biological Sciences. 270 (1529): 2167–72. doi:10.1098/rspb.2003.2502. PMC 1691489. PMID 14561281. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  75. Burriss RP, Little AC, Nelson EC (2007). "2D:4D and sexually dimorphic facial characteristics". Archives of Sexual Behavior. 36 (3): 377–84. doi:10.1007/s10508-006-9136-1. PMID 17203400. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  76. Bower, Bruce (Aug. 1998). "Male good looks take feminine turn". BNet. {{cite news}}: Check date values in: |date= (help)
  77. "Finger Length Predicts SAT Performance". Live Science. May 2007.
  78. The Treatment of Psychopathic and Antisocial Personality Disorders: A Review - Jessica H Lee, 1999 Clinical Decision Making Support Unit, Broadmoor Hospital
  79. Firestone P, Bradford JM, Greenberg DM, Larose MR (1998). "Homicidal sex offenders: psychological, phallometric, and diagnostic features". The Journal of the American Academy of Psychiatry and the Law. 26 (4): 537–52. doi:10.1177/0093854806288176. PMID 9894211.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  80. The Mental Health Act (UK) Reforming The Mental Health Act, Part II, High risk patients Accessed June 26, 2006
  81. Paul Harrison & John Geddes (2005-07-18). Lecture Notes: Psychiatry. Blackwell Publishing. pp. 163–165. ISBN 978-1-4051-1869-9.
  82. Fitch, W. Lawrence (2003). "Sexual Offender Commitment in the United States: Legislative and Policy Concerns". Annals of the New York Academy of Sciences. 989 (SEXUALLY COERCIVE BEHAVIOR: Understanding and Management): 489–501. doi:10.1111/j.1749-6632.2003.tb07328.x. PMID 12839921.
  83. ^ Monahan, Steadman, Henry J. (1999). Mentally Disordered Offenders: Perspectives from Law and Social Science. Lecture notes in mathematics 1358. Springer-Verlag. pp. 279–282. doi:10.1007/b62130. ISBN 3-540-63293-X.
  84. Alexander, R. (1993). "The Civil Commitment of Sex Offenders in Light of Foucha v. Louisiana". Criminal Justice and Behavior. 20 (4): 371. doi:10.1177/0093854893020004005.
  85. ^ Washington State Legislature Revised Code of Washington (RCW 71.06.010 ) Accessed December 28, 2007
  86. Statutes and Amendments to the Codes of California 1939, page 1783, ch. 447, enacted June 6, 1939
  87. Statutes and Amendments to the Codes of California 1941, page 2462, ch. 884, enacted June 28, 1941.
  88. Porter, Stephen; Ten Brinke, Leanne; Wilson, Kevin (2009). "Crime profiles and conditional release performance of psychopathic and non-psychopathic sexual offenders". Legal and Criminological Psychology. 14: 109. doi:10.1348/135532508X284310.
  89. Coid J, Yang M, Ullrich S, Roberts A, Hare RD (2009). "Prevalence and correlates of psychopathic traits in the household population of Great Britain". International Journal of Law and Psychiatry. 32 (2): 65–73. doi:10.1016/j.ijlp.2009.01.002. PMID 19243821.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  90. Coid J, Yang M, Ullrich S; et al. (2009). "Psychopathy among prisoners in England and Wales". International Journal of Law and Psychiatry. 32 (3): 134–41. doi:10.1016/j.ijlp.2009.02.008. PMID 19345418. {{cite journal}}: Explicit use of et al. in: |author= (help)CS1 maint: multiple names: authors list (link)
  91. ^ Millon, Theodore (1996). Disorders of Personality: DSM-IV and Beyond. New York: John Wiley & Sons, Inc. p. 430. ISBN 0-471-01186-X. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help) Cite error: The named reference "millon" was defined multiple times with different content (see the help page).
  92. Mythos and Mental Illness: Psychopathy, Fantasy, and Contemporary Moral Life (2008)
  93. The pathology of mind, by Henry Maudsley, Chapter 3, p. 77
  94. Millon, Theodore (2002). Psychopathy: Antisocial, Criminal, and Violent Behavior. Guidford Press. pp. 3–18. ISBN 1-57230-864-8. Retrieved 2008-01-13. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)
  95. Meloy, J. Reid (1988). The Psychopathic Mind: Origins, Dynamics, and Treatment. Northvale, NJ: Jason Aronson Inc. p. 9. ISBN 0-87668-311-1.
  96. Psychopathic personality: a conceptual problem (1977)
  97. Cameron, Deborah (1987). The Lust to Kill. Washington Square, NY: New York University Press. pp. 87–94. ISBN 0-8147-1408-0.
  98. Beauchaine, Theodore P.; Klein, Daniel N.; Crowell, Sheila E.; Derbidge, Christina; Gatzke-Kopp, Lisa (2009). "Multifinality in the development of personality disorders: A Biology × Sex × Environment interaction model of antisocial and borderline traits". Development and Psychopathology. 21 (3): 735–70. doi:10.1017/S0954579409000418. PMC 2709751. PMID 19583882.
  99. Gollan JK, Lee R, Coccaro EF (2005). "Developmental psychopathology and neurobiology of aggression". Development and Psychopathology. 17 (4): 1151–71. PMID 16613435.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  100. Lee R, Coccaro ER. Neurobiology of impulsive aggression: Focus on serotonin and the orbitofrontal cortex. In: Flannery DJ, Vazsonyi AT, Waldman ID, editors. The Cambridge handbook of violent behavior and aggression. New York: Cambridge University Press; 2007. pp. 170–186. ISBN 9780521607858
  101. van Goozen SH, Fairchild G, Snoek H, Harold GT (2007). "The evidence for a neurobiological model of childhood antisocial behavior". Psychological Bulletin. 133 (1): 149–82. doi:10.1037/0033-2909.133.1.149. PMID 17201574. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)

Bibliography

External links

Categories: