CHAPTER 12 – PERSONALITY DISORDER
• Personality is all the ways we have of acting, thinking, believing, and
feeling that make each of us unique.
• A personality trait is a complex pattern of behaviour, thought, and feeling
that is stable across time and across many situations
DEFINING AND DIAGNOSING PERSONALITY DISORDERS
• A personality disorder is a long-standing pattern of maladaptive
behaviours, thoughts, and feelings.
• To be diagnosed with a personality disorder, an adult must have shown
these symptoms since adolescence or early adulthood.
• The DSM-IV-TR calls special attention to personality disorders and treats
them as different from the acute disorders, such as major depression and
schizophrenia, by placing the personality disorders on Axis II of the
diagnostic system, instead of on Axis I with the acute disorders
• People diagnosed with a personality disorder often experience one of the
acute disorders, such as major depression or substance abuse, at
sometime in their lives
• Indeed, these acute disorders are often what brings them to the attention
• People diagnosed with personality disorders tend not to seek therapy until
they experience a bout of major depression or until their substance abuse
lands them in jail or the hospital, because they often do not see the
behaviours that constitute their personality disorder as maladaptive. In
addition, they often have serious problems relating to other people, and
these relationship problems may bring them into therapy.
• The DSM-IV-TR groups personality disorders into three clusters
o Cluster A includes three disorders characterized by odd or
eccentric behaviours and thinking
paranoid personality disorder, schizoid personality disorder,
and schizotypal personality disorder.
Each of these disorders has some of the features of
schizophrenia, but people diagnosed with these personality
disorders are not psychotic.
Their behaviours are simply odd and often inappropriate.
o Cluster B includes four disorders characterized by dramatic, erratic,
and emotional behaviour and interpersonal relationships
antisocial personality disorder, histrionic personality disorder,
borderline personality disorder, and narcissistic personality
People diagnosed with these disorders tend to be
manipulative, volatile, and uncaring in social relationships
and prone to impulsive behaviours. They may behave in wild and exaggerated ways or even
engage in suicidal attempts to try to gain attention
o Cluster C includes three disorders characterized by anxious and
fearful emotions and chronic self-doubt
dependent personality disorder, avoidant personality
disorder, and obsessive-compulsive personality disorder.
People diagnosed with these disorders have little self-
confidence and difficult relationships with others
• The criteria for diagnosing personality disorders are vaguer than the
criteria for many of the other, more acute disorders and thus leave more
room for misapplication
Problems with the DSM Categories
• Many theorists have raised objections to the DSM-IV-TR conceptualization
and organization of the personality disorders
• First, the DSM-IV-TR treats these disorders as categories.
o That is, each disorder is described as if it represents something
qualitatively different from a “normal” personality, yet substantial
evidence that several of the disorders recognized by the DSM-IV-
TR represent the extreme versions of normal personality traits
o have demonstrated that all of the DSM Axis II disorders can be
represented by a restricted list of normal personality traits and that
much of the overlap between Axis II disorders is due to common
• Second, a great deal of overlap exists in the diagnostic criteria for the
various personality disorders in the DSM-IV-TR.
o The majority of people who are diagnosed with one disorder tend to
meet the diagnostic criteria for at least one more personality
o This overlap suggests that there actually may be fewer personality
disorders that adequately account for the variation in personality
o The overlap also makes it very difficult to obtain reliable diagnoses
of the personality disorders
• Third, diagnosing a personality disorder often requires information that is
hard for a clinician to obtain
o clinicians must observe behavioural manifestations of problems and
then infer which traits are responsible for these manifestations.
• Fourth, the personality disorders are conceptualized as stable
characteristics of an individual.
o Longitudinal studies have found, however, that people diagnosed
with these disorders vary over time in how many symptoms they
exhibit and the severity of these symptoms, so that they go in and
out of the diagnosis over time o In particular, people often look as if they have a personality disorder
when they are suffering from an acute Axis I disorder, such as
major depression, but then their personality disorder symptoms
seem to diminish when their Axis I disorder symptoms subside.
o Livesley and his colleagues have noted that Axis II disorders
include the assessment of features that are ostensibly stable and
features that are more state-like and so instability in personality
disorders is likely built into their diagnostic description
• In response to these inherent problems in the diagnosis of Axis II
disorders, a group of expert personality researchers, including John
Livesley, convened to discuss the merits of categorical versus dimensional
models of personality disorders and to propose changes for the
development of the DSM-V
Gender and Ethnic Biases in Construction and Application
• differences exist in the frequency with which men and women are
diagnosed with certain personality disorders and in the frequency with
which different ethnic groups are diagnosed.
• One of the greatest controversies in the literature on personality disorders
concerns claims that these apparent differences actually result from
biases in the construction of these disorders in the DSM-IV-TR or in
clinicians' applications of the diagnostic criteria
• First, come theorists, have argued that the diagnoses of histrionic,
dependent, and borderline personality disorders, which are characterized
by flamboyant behaviour, emotionality, and dependence on others, are
simply extreme versions of negative stereotypes of women's personalities
o For this reason, clinicians may sometimes be too quick to see these
characteristics in women clients and to apply these diagnoses.
o It has also been argued that the diagnostic criteria for antisocial,
paranoid, and obsessive-compulsive personality disorders, which
are characterized by violent, hostile, and controlling behaviours,
represent extremes of negative stereotypes of men.
o Clinicians may be biased to overapply these diagnoses to men but
not to women
• Another way that the DSM-IV-TR constructions of personality disorders
may be biased is in not recognizing that the expressions of the symptoms
of a disorder may naturally vary between groups.
o For example, the diagnostic criteria for antisocial personality
disorder emphasize overt signs of callous and cruel antisocial
behaviour, including committing crimes against property and
o Women with antisocial personality disorder may be less likely than
men with the disorder to engage in such overt antisocial
behaviours, because of greater social sanctions against women for
doing so. o Instead, women with antisocial personality disorder may find more
subtle or covert ways of being antisocial, such as acting cruelly
toward their children or covertly sabotaging people at work
o the same argument has been made about possible gender
differences in the expression of a childhood precursor to antisocial
personality disorder: conduct disorder.
o It may also be that certain ethnic groups, such as European North
Americans, are better able to hide their symptoms of callous and
cruel behaviour, because they hold more social power and can
exercise these tendencies in ways that are deemed acceptable in
the majority culture
• Similarly, some theorists have argued that the DSM-IV-TR ignores or
downplays possible masculine ways of expressing dependent, histrionic,
and borderline personality disorders, and this bias contributes to an under-
diagnosis of these disorders in men
o For example, one of the criteria for histrionic personality disorder is
“consistently uses physical appearance to draw attention to the
o Although the DSM-IV-TR notes that men may express this
characteristic by acting “macho” and bragging about their athletic
skills, the wording of the criterion brings to mind everyday
behaviours more common among women, such as wearing
• Even if the DSM-IV-TR criteria for personality disorders are not biased in
their construction, they may be biased in their application.
o Clinicians may be too quick to see histrionic, dependent, and
borderline personality disorders in women or antisocial personality
disorder in men.
o Several studies have shown that, when clinicians are presented
with the description of a person who exhibits many of the symptoms
of one of these disorders—say, a histrionic personality disorder—
they are more likely to make that diagnosis if the person is
described as a female than if the person is described as a male
o It is important to note that these studies did not suggest that the
DSM-IV-TR criteria are themselves gender-biased—only that
clinicians seem to be misapplying the DSM-IV-TR according to
• In response to these concerns about the biased application of the criteria
for personality disorders, it has been argued that structured interviews,
rather than unstructured interviews, should be used in assessing
o The idea is that the use of structured interviews would increase the
chances that the DSM-IV-TR criteria would be applied
systematically and fairly to men and women and to people of
different ethnic groups. o Studies that have used structured interviews tend to show less
gender bias in clinicians' applications of the DSM-IV-TR personality
disorder criteria than do studies that have used unstructured
• Studies that have compared the impact of structured clinical interviews
with that of self-report instruments on the distribution of personality
disorder diagnoses among ethnic groups have found that the two methods
of assessment produce similar results
o These results suggest that it is not just clinicians' bias in applying
the DSM-IV-TR criteria that leads to gender and ethnic differences
in the apparent prevalence of the disorder.
• DSM-IV-TR criteria should be balanced to include equal numbers of
symptoms and diagnoses that are pathological variants of masculine and
feminine personality traits
o Indeed, the authors of the DSM-IV-TR attempted to include more
masculine variations of symptoms thought to be more common in
women (e.g., masculine forms of dependency) and more feminine
versions of stereotypical masculine symptoms (e.g., feminine forms
of antisocial behaviour).
o Some theorists argue the DSM-IV-TR did not go far enough and
that the next edition should strive for even greater balance in
pathologizing men and women.
o However, others argue that, just because it would be possible to
construct a set of diagnostic criteria that yields equal numbers of
men and women with each personality disorder, or equal numbers
of people in different ethnic groups with each disorder, it does not
mean that these criteria reflect the true structure and distribution of
personality disorders in people.
ODD-ECCENTRIC PERSONALITY DISORDERS
• People diagnosed with the odd-eccentric personality disorders behave
in ways that are similar to the behaviours of people with schizophrenia or
paranoid psychotic disorder, but they retain their grasp on reality to a
greater degree than do people who are psychotic.
• That is, they may be paranoid, speak in odd and eccentric ways that make
them difficult to understand, have difficulty relating to other people, and
have unusual beliefs or perceptual experiences that fall short of delusions
• Some researchers consider this group of personality disorders to be part
of the “schizophrenia spectrum”
• That is, these disorders may be precursors to schizophrenia in some
people or may be milder versions of schizophrenia.
• These disorders often occur in people who have first-degree relatives with
schizophrenia Paranoid Personality Disorder
• The defining feature of paranoid personality disorder is a pervasive and
unwarranted mistrust of others.
• People diagnosed with this disorder deeply believe that other people are
chronically trying to deceive them or to exploit them and are preoccupied
with concerns about the loyalty and trustworthiness of others.
• They are hypervigilant for confirming evidence of their suspicions. They
are often penetrating observers of situations, noting details that most other
• Moreover, people diagnosed with paranoid personality disorder consider
these events highly meaningful and spend a great deal of time trying to
decipher these clues about other people's true intentions.
• They are also overly sensitive to criticism or potential criticism
• People with paranoid personality disorder tend to misinterpret or
overinterpret situations in line with their suspicions
• They are resistant to rational arguments against their suspicions and may
take the fact that another person is arguing with them as evidence that this
person is part of the conspiracy against them.
• Some become withdrawn from others in an attempt to protect themselves,
but others are aggressive and arrogant, sure that their way of looking at
the world is right and superior and that the best defence against the
conspiring of others is a good offence
Prevalence and Prognosis of Paranoid Personality Disorder
• For instance, epidemiological studies suggest that between 0.5% and
5.6% of people in the general population can be diagnosed with paranoid
• Among people treated for paranoid personality disorder, males outnumber
females three to one
• People diagnosed with the disorder appear to be at increased risk for a
number of acute psychological problems, including major depression,
anxiety disorders, substance abuse, and psychotic episodes
• Not surprisingly, their interpersonal relationships, including intimate ones,
tend to be unstable.
• Retrospective studies suggest that their prognosis is generally poor, with
their symptoms intensifying under stress
Theories and Treatment of Paranoid Personality Disorder
• Some family history studies have shown that paranoid personality disorder
is somewhat more common in the families of people with schizophrenia
than in the families of healthy control subjects. • This finding suggests that paranoid personality disorder may be part of the
schizophrenic spectrum of disorders
• Cognitive theorists see paranoid personality disorder as the result of an
underlying belief that other people are malevolent and deceptive,
combined with a lack of self-confidence about being able to defend
oneself against others
• Thus, the person must always be vigilant for signs of others' deceit or
criticism and must be quick to act against others
• People diagnosed with paranoid personality disorder usually come into
contact with clinicians only when they are in crisis.
• They may seek treatment for severe symptoms of depression or anxiety
but often do not feel a need for treatment of their paranoia.
• In addition, therapists' attempts to challenge their paranoid thinking are
likely to be misinterpreted in line with their paranoid belief systems
• For this reason, it can be quite difficult to treat paranoid personality
• To gain the trust of a person diagnosed with a paranoid personality
disorder, the therapist must be calm, respectful, and extremely
• The therapist must behave in a highly professional manner at all times, not
attempting to engender a warm, personal relationship with the client that
might be misinterpreted.
• The therapist cannot directly confront the client's paranoid thinking but
must rely on more indirect means of raising questions in the client's mind
about his or her typical way of interpreting situations.
• Although many therapists do not expect paranoid clients to achieve full
insight into their problems, they hope that, by developing at least some
degree of trust in the therapist, the client can learn to trust others a bit
more and thereby develop somewhat improved interpersonal relationships
• Cognitive therapy for people diagnosed with this disorder focuses on
increasing their sense of self-efficacy for dealing with difficult situations,
thus decreasing their fear and hostility toward others
Schizoid Personality Disorder
• People diagnosed with schizoid personality disorder lack the desire to
form interpersonal relationships and are emotionally cold in interactions
• Other people describe them as aloof, reclusive, and detached or as dull,
uninteresting, and humourless.
• People diagnosed with this disorder show little emotion in interpersonal
• They view relationships with others as unrewarding, messy, and intrusive
• long-standing avoidance of relationships with other people and his lack of
emotions or emotional understanding. • As is often the case with people diagnosed with personality disorders, he
seeks the help of a clinician only when a crisis occurs
Prevalence of Schizoid Personality Disorder
• Schizoid personality disorder is quite rare, with about 0.4% to 1.7% of
adults manifesting the disorder at sometime in their lives
• Among people seeking treatment for this disorder, males outnumber
females about three to one
• They can function in society, particularly in occupations that do not require
Theories and Treatment of Schizoid Personality Disorder
• A slightly increased rate of schizoid personality disorder occurs in the
relatives of persons with schizophrenia, but the link between the two
disorders is not clear
• Twin studies of the personality traits associated with schizoid personality
disorder, such as low sociability and low warmth, strongly suggest that
these personality traits may be partially inherited
• This evidence for the heritability of schizoid personality disorder is only
• In terms of the possible antecedents to the development of schizoid
personality disorder, a study by Malcolm West and his colleagues at the
University of Calgary found that insecure attachment patterns, particularly
compulsive self-reliance, were unique to the diagnosis schizoid personality
• Psychosocial treatments for schizoid personality disorder focus on
increasing the person's social skills, social contacts, and awareness of his
or her own feelings
• The therapist may model the expression of feelings for the client and help
the client identify and express his or her own feelings.
• Social skills training, done through role-plays with the therapist and
through homework assignments in which the client tries out new social
skills with other people, is an important component of cognitive therapies.
• Some therapists recommend group therapy for people with schizoid
• In the context of group sessions, the group members can model
interpersonal relationships and the person with schizoid personality
disorder can practise new social skills directly with others.
Schizotypal Personality Disorder
• As with people diagnosed with schizoid personality disorder, people
diagnosed with schizotypal personality disorder tend to be socially
isolated, to have a restricted range of emotions, and to be uncomfortable
in interpersonal interactions. • As children, people who develop schizotypal personality disorder are
passive, socially unengaged, and hypersensitive to criticism
• The distinguishing characteristics of schizotypal personality disorder are
its oddities in cognition, which generally fall into four categories
o The first is paranoia or suspiciousness.
People diagnosed with schizotypal personality disorder
perceive other people as deceitful and hostile, and much of
their social anxiety emerges from this paranoia.
o The second category is ideas of reference.
People diagnosed with schizotypal personality disorder tend
to believe that random events or circumstances are related
o The third type of odd cognition is odd beliefs and magical thinking
For example, they may believe that others know what they
o The fourth category of odd thought consists of illusions that are just
short of hallucinations.
For example, they may think they see people in the patterns
• In addition to having these oddities of thought, people diagnosed with
schizotypal personality disorder tend to have speech that is tangential,
circumstantial, vague, or overelaborate. In interactions with others, they
may have inappropriate or no emotional responses to what other people
say or do.
• Their behaviours are also odd, sometimes reflecting their odd thoughts.
• They may be easily distracted or fixate on an object for long periods, lost
in thought or fantasy.
• On neuropsychological tests, people with schizotypal personality disorder
show deficits in working memory, learning, and recall that are similar to
those shown by people with schizophrenia
• Although the quality of these oddities of thought, speech, and behaviour is
similar to that in schizophrenia, it is not as severe as in schizophrenia, and
people diagnosed with schizotypal personality disorder maintain basic
contact with reality.
Prevalence Schizotypal Personality Disorder
• Between 0.6% and 5.2% of people will be diagnosed with schizotypal
personality disorder at sometime in their lives
• Among people seeking treatment, it is more than twice as commonly
diagnosed in males as in females • As with the other odd-eccentric personality disorders, people diagnosed
with schizotypal personality disorder are at an increased risk for
depression and for schizophrenia or isolated psychotic episodes
• For a person to be given a diagnosis of schizotypal personality disorder,
his or her odd or eccentric thoughts cannot be part of cultural beliefs, such
as a cultural belief in magic or specific superstitions.
• Still, some psychologists have argued that people of colour are more often
diagnosed with schizophrenic-like disorders, such as schizotypal
personality disorder, than are whites, because white clinicians often
misinterpret culturally bound beliefs as evidence of schizotypal thinking
• One large U.S. study of people in treatment found that the African-
American patients were more likely than the Caucasian or Hispanic
patients to be diagnosed with schizotypal personality disorder on both self-
report and standardized diagnostic interviews
o This finding suggests that African Americans may be diagnosed
with this disorder relatively frequently, even when steps are taken to
avoid clinician bias.
o It is possible that African Americans are more likely to be exposed
to conditions that enhance a biological vulnerability to
o Such conditions include perinatal brain damage, urban living, and
low socioeconomic status
Theories and Treatment of Schizotypal Personality Disorder
• Family history, adoption, and twin studies all suggest that schizotypal
personality disorder is transmitted genetically, at least to some degree
• They found that these psychotic-like traits are highly inheritable
• In addition, schizotypal personality disorder is much more common in the
first-degree relatives of people with schizophrenia than in the relatives of
either psychiatric patients or healthy control groups
• This finding supports the view that schizotypal personality disorder is a
mild form of schizophrenia, which is transmitted through genes in ways
similar to those of schizophrenia.
• Similarly, some of the non-genetic biological factors implicated in
schizophrenia are also present in people with schizotypal personality
o In particular, people diagnosed with this disorder show problems in
the ability to sustain attention on cognitive tasks, as well as deficits
in memory similar to those seen in people with schizophrenia
o Two separate groups of researchers at McGill University have
demonstrated that problems with smooth pursuit eye tracking, a
behavioural pattern associated with frontal lobe dysfunction, which is associated with schizophrenia, are also observed in participants
elevated on measures of schizotypal traits
• People with schizotypal personality disorder also tend to show a
dysregulation of the neurotransmitter dopamine in the brain, as do people
o Thus, like people with schizophrenia, people with schizotypal
personality disorder may have abnormally high levels of dopamine
in some areas of their brains.
o Finally, people with schizotypal personality disorder show
abnormalities in the structure of their brains that are similar to those
seen in people with schizophrenia
• Schizotypal personality disorder is most often treated with the same drugs
that are used to treat schizophrenia, including traditional neuroleptics,
such as haloperidol and thiothixene, and the atypical antipsychotics, such
o As in schizophrenia, these drugs appear to relieve psychotic-like
symptoms, including ideas of reference, magical thinking, and
o Antidepressants are sometimes used to help people with
schizotypal personality disorder who are experiencing significant
• Although few psychological theories of schizotypal personality disorder
have been developed, psychological therapies have been created to help
people overcome some of their symptoms.
• In psychotherapy, it is especially important for therapists to establish good
relationships with clients, because these clients typically have few close
relationships and tend to be paranoid
• The next step in therapy is to help clients increase social contacts and
learn socially appropriate behaviours through social skills training.
• Group therapy may be especially helpful in increasing clients' social skills.
The crucial component of cognitive therapy with clients diagnosed with
schizotypal personality disorder is teaching them to look for objective
evidence in the environment for their thoughts and to disregard bizarre
DRAMATIC-ERRATIC PERSONALITY DISORDERS
• People diagnosed with the dramatic-erratic personality disorders
engage in behaviours that are dramatic and impulsive, and they often
show little regard for their own safety or the safety of others
• They may also act in hostile, even violent ways against others. One of the
core features of this group of disorders is a lack of concern for others
Antisocial Personality Disorder
• The key features of antisocial personality disorder, as defined by the
DSM-IV-TR, are an impairment in the ability to form positive relationships with others and a tendency to engage in behaviours that violate basic
social norms and values.
• People with this disorder are deceitful, as indicated by the repeated lying
to or conning of others for personal profit or pleasure
• people with this disorder commit violent criminal offences against others,
including assault, murder, and rape, much more frequently than do people
without the disorder
• When caught, they tend to have little remorse, seeming indifferent to the
pain and suffering they have caused others
• A prominent characteristic of antisocial personality disorder is poor control
o People with this disorder have a low tolerance for frustration and
often act impetuously, with no apparent concern for the
consequences of their behaviour.
o They often take chances and seek thrills with no concern for
o They are easily bored and restless, unable to endure the tedium of
routine or to persist at the day-to-day responsibilities of marriage or
o As a result, they tend to drift from one relationship to another and
often are in lower-status jobs.
o They may engage in criminal activity impulsively, and 50% to 80%
of men in jail may be diagnosable with antisocial personality
• Antisocial personality disorder (ASPD), as defined by the DSM-IV-TR,
differs in some important ways from the characterization of psychopathy.
o Whereas the DSM-IV-TR emphasizes observable antisocial
behaviours in the diagnosis of ASPD emphasized certain broad
personality traits in psychopathy.
• More recently, Robert Hare (1991) has built on Cleckley's work to develop
criteria for the diagnosis of psychopathy, which have been supported in
o These criteria include a superficial charm, a grandiose sense of
self-worth, a tendency toward boredom and need for stimulation,
pathological lying, an ability to be conning and manipulative, and a
lack of remorse.
o People with psychopathy are cold and callous, gaining pleasure by
competing with and humiliating others.
o They can be cruel and malicious, and they often insist on being
seen as faultless.
o They are dogmatic in their opinions. However, when they need to
be, people with psychopathy can be gracious and cheerful, until
they get what they want.
o They then may revert to being brash and arrogant. o He suggested that the difference between psychopaths who
become successful people and psychopaths who end up in jail is
that the successful ones are better able to maintain an outward
appearance of being normal.
o They may be able to do so because they have superior intelligence
and can put on a “mask of sanity” and superficial social charm to
achieve their goals.
• For the psychopaths who do end up in a life of crime, research by Hare,
Williamson, and Harpur (1988) has demonstrated that criminal activities,
time spent in prison, and conviction rates remain stable up until
approximately age 40, and then it appears that a large percentage of
psychopaths burn out in middle age, with dramatically reduced criminal
• Research on people with antisocial tendencies is mixed as to whether
people are defined in terms of the Cleckley/Hare criteria for psychopathy,
DSM-IV-TR criteria for antisocial personality disorder, or simply in terms of
having a record of severe criminal conduct
Prevalence of Antisocial Personality Disorder
• Epidemiological studies of antisocial personality disorder, as defined by
the DSM-IV-TR, suggest it is one of the most common personality
• Men are substantially more likely than women to be diagnosed with this
• Although some theorists have argued that clinicians are more likely to see
antisociality in African Americans than in whites, epidemiological studies
have not found ethnic differences in rates of diagnosis
• People diagnosed with this personality disorder are somewhat more likely
than people diagnosed with the other personality disorders to have low
levels of education
• As many as 80% of people with antisocial personality disorder abuse
substances, such as alcohol and illicit drugs
o Substance abuse, such as binge drinking, may be just one form of
the impulsive behaviour that is part of antisocial personality
o Substance abuse probably feeds impulsive and antisocial
behaviour among people with this personality disorder.
o Alcohol and other substances may reduce any inhibitions they do
have, making it more likely they will lash out violently at others.
o People with this disorder are also at a somewhat increased risk for
suicide attempts (particularly females) and for violent death
• The tendency to engage in antisocial behaviours is one of the most stable
personality characteristics in this disorder o Many adults with antisocial personality disorder show a disregard
for societal norms and a tendency for antisocial behaviour
beginning in childhood, and most would have been diagnosed with
conduct disorder as children.
o For some people with this disorder, however, the antisocial
behaviour diminishes as they age.
o This is particularly true of people who were not antisocial as
children but became antisocial as adolescents or young adults
o This tendency may be due to a psychological or biological
maturation process, or many people with this disorder may simply
be jailed or otherwise constrained by society from acting out their
Theories of Antisocial Personality Disorder
• The support is substantial for a genetic influence on antisocial behaviours,
particularly criminal behaviours
• Twin studies find that the concordance rate for such behaviours is near
50% in MZ twins, compared with 20% or lower in DZ twins
• Adoption studies find that the criminal records of adopted sons are more
similar to the records of their biological fathers than to those of their
• Family history studies show that the family members of people with
antisocial personality disorder have increased rates of this disorder, as
well as increased rates of alcoholism and criminal activity
• Most theorists suggest that antisocial behaviour is not the result of one
gene or even a small number of genes.
• Instead, some people appear to be born with a number of genetically
influenced deficits that make them ill equipped to manage ordinary life,
putting them at risk for antisocial behavior
• One long-standing theory is that aggressiveness, such as that shown by
people with antisocial personality disorder, is linked to the hormone
• a role for testosterone in most forms of aggression is weak
• Hormones, such as testosterone, may play a more important role during
prenatal development in organizing the fetal brain in ways that promote or
inhibit aggressiveness, rather than having a direct influence on behaviour
in adolescence or adulthood.
• Recall that a prominent characteristic of antisocial personality disorder is a
difficulty in inhibiting impulsive behaviours
• Some researchers argue that poor impulse control is at the heart of
antisocial personality disorder • What might be the biological causes of poor impulse control? Many animal
studies have shown that impulsive and aggressive behaviours are linked
to low levels of the neurotransmitter serotonin, leading to the suggestion
that people with antisocial personality disorder may also have low levels of
• Research with children who show antisocial tendencies indicates that a
significant percentage, perhaps the majority, have attention deficit
hyperactivity disorder (ADHD), which involves significant problems with
inhibiting impulsive behaviours and maintaining attention
o The disruptive behaviour of these children leads to frequent
punishment and to rejection by peers, teachers, and other adults.
o These children then become even more disruptive, and some
become overtly aggressive and antisocial in their behaviours and
o Thus, at least some adults with antisocial personality disorder may
have lifelong problems with attentional deficits and hyperactivity,
which then contribute to lifelong problems with controlling their
• People with antisocial personalities also show deficits in verbal skills and
in the executive functions of the brain.
o These functions include the ability to sustain concentration, abstract
reasoning, concept and goal formation, the ability to anticipate and
plan, the capacity to program and initiate purposive sequences of
behaviour, self-monitoring and self-awareness, and the ability to
shift from maladaptive patterns of behaviour to more adaptive ones
o In turn, some, but not all, studies have found differences between
antisocial adults (usually prison inmates) and the general
population in the structure or functioning of the temporal and frontal
lobes of the brain
o These deficits in brain functioning and structure might be tied to
medical illnesses and exposure to toxins during infancy and
childhood, both of which are more common among people who
develop criminal records than among those who do not
o Conversely, these deficits might be tied to genetic abnormalities.
o Whatever their causes, low verbal intelligence and deficits in
executive functions might contribute to poor impulse control and
difficulty in anticipating the consequences of one's actions
• persons with antisocial personality disorder show low levels of arousability,
measured by relatively low resting heart rates, low skin conductance
activity, and excessive slow-wave electroencephalogram readings
o One interpretation of these data is that low levels of arousal
indicate low levels of fear in response to threatening situations
• Fearlessness, however, can be put to good use
o However, fearlessness may also predispose some people to
antisocial and violent behaviours, such as fighting and robbery, which require fearlessness to execute. In addition, low-arousal
children may not fear punishment and may not be deterred from
antisocial behaviour by the threat of punishment.
• A second theory of how low arousability contributes to antisocial
personality disorder is that chronically low arousal is an uncomfortable
state and leads to stimulation seeking
o Again, if an individual seeks stimulation through prosocial or neutral
acts, such as skydiving, stimulation seeking may not lead to
o But some individuals may seek stimulation through antisocial acts
that are dangerous or impulsive, such as robbery or fights.
o The direction that stimulation seeking takes—toward antisocial
activities or toward more neutral activities—may depend on the
reinforcement that individuals receive for their behaviours.
o Those who are rewarded for antisocial behaviour by family and
peers may develop antisocial personalities, whereas those who are
consistently punished for such behaviours and given alternative,
more neutral behaviours may not
• Intelligence may also influence the direction that stimulation seeking takes
o Children who are intelligent experience more rewards from school
and, thus, may be more influenced by the norms of adults and
positive peer groups in the choices they make for seeking
stimulation. In contrast, children who are less intelligent may find
school punishing and may turn to deviant peer groups for
gratification and stimulating activities
• Much of the empirical research on the social and cognitive factors that
contribute to antisocial behaviour has been conducted with children.
o Many children with antisocial tendencies come from homes in
which they have experienced harsh and inconsistent parenting and
o The parents of these children alternate between being neglectful
and being hostile and violent toward their children. These children
learn ways of thinking about the world that promote antisocial
o They enter social interactions with the assumption that other
children will be aggressive toward them, and they interpret the
actions of their peers in line with this assumption.
o As a result, they are quick to engage in aggressive behaviours
o These social and cognitive factors alone may be enough to lead to
antisocial personalities in some children and adults
• Dodge and Pettit integrated the myriad biological, social, and cognitive
factors associated with antisociality into a comprehensive model o According to this model, some people are born with neural,
endocrine, and psychophysiological dispositions, or are born into
sociocultural contexts, that put them at risk for antisocial behaviour
throughout their lifetimes.
o Early symptoms of aggression and oppositional behaviour in a child
lead to, and interact with, harsh disciplin