low-activity variant (maoa-l) who experience such maltreatment being more likely to develop antisocial behavior than those with the high-activity variant (maoa-h). even when environmental interactions (e.g. emotional abuse) are controlled for, a small association between maoa-l and aggressive and antisocial behavior remains. the gene that encodes for the serotonin transporter (scl6a4), a gene that is heavily researched for its associations with other mental disorders, is another gene of interest in antisocial behavior and personality traits. genetic associations studies have suggested that the short "s" allele is associated with impulsive antisocial behavior and aspd in the inmate population. however, research into psychopathy find that the long "l" allele is associated with the factor 1 traits of psychopathy, which describes its core affective (e.g. lack of empathy, fearlessness) and interpersonal (e.g. grandiosity, manipulativeness) personality disturbances. this is suggestive of two different forms, one associated more with impulsive behavior and emotional dysregulation, and the other with predatory aggression and affective disturbance, of the disorder. various other gene candidates for aspd have been identified by a genome-wide association study published in 2016. several of these gene candidates are shared with attention-deficit hyperactivity disorder, with which aspd is comorbid. furthermore, the study found that those who carry four mutations on chromosome 6 are 50 percent more likely to develop antisocial personality disorder than those who do not. hormones and neurotransmitters traumatic events can lead to a disruption of the standard development of the central nervous system, which can generate a release of hormones that can change normal patterns of development. aggressiveness and impulsivity are among the possible symptoms of aspd. testosterone is a hormone that plays an important role in aggressiveness in the brain. for instance, criminals who have committed violent crimes tend to have higher levels of testosterone than the average person. the effect of testosterone is counteracted by cortisol which facilitates the cognitive control of impulsive tendencies. one of the neurotransmitters that has been discussed in individuals with aspd is serotonin, also known as 5ht. a meta-analysis of 20 studies found significantly lower 5-hiaa levels (indicating lower serotonin levels), especially in those who are younger than 30 years of age. while it has been shown that lower levels of serotonin may be associated with aspd, there has also been evidence that decreased serotonin function is highly correlated with impulsiveness and aggression across a number of different experimental paradigms. impulsivity is not only linked with irregularities in 5ht metabolism, but may be the most essential psychopathological aspect linked with such dysfunction. correspondingly, the dsm classifies "impulsivity or failure to plan ahead" and "irritability and aggressiveness" as two of seven sub-criteria in category a of the diagnostic criteria of aspd. some studies have found a relationship between monoamine oxidase a and antisocial behavior, including conduct disorder and symptoms of adult aspd, in maltreated children. neurological antisocial behavior may be related to head trauma. antisocial behavior is associated with decreased grey matter in the right lentiform nucleus, left insula, and frontopolar cortex. increased volumes have been observed in the right fusiform gyrus, inferior parietal cortex, right cingulate gyrus, and post central cortex. intellectual and cognitive ability is often found to be impaired or reduced in the aspd population. contrary to stereotypes in popular culture of the "psychopathic genius", antisocial personality disorder is associated with both reduced overall intelligence and specific reductions in individual aspects of cognitive ability. these deficits also occur in general-population samples of people with antisocial traits and in children with the precursors to antisocial personality disorder. people that exhibit antisocial behavior tend to demonstrate decreased activity in the prefrontal cortex. the association is more apparent in functional neuroimaging as opposed to structural neuroimaging. the prefrontal cortex is involved in many executive functions, including behavior inhibitions, planning ahead, determining consequences of action, and differentiating between right and wrong. however, some investigators have questioned whether the reduced volume in prefrontal regions is associated with antisocial personality disorder, or whether they result from co-morbid disorders, such as substance use disorder or childhood maltreatment. moreover, it remains an open question whether the relationship is causal, i.e., whether the anatomical abnormality causes the psychological and behavioral abnormality, or vice versa. cavum septi pellucidi (csp) is a marker for limbic neural maldevelopment, and its presence has been loosely associated with certain mental disorders, such as schizophrenia and post-traumatic stress disorder. one study found that those with csp had significantly higher levels of antisocial personality, psychopathy, arrests and convictions compared with controls. family environment many studies suggest that the social and home environment has contributed to the development of antisocial behavior. the parents of these children have been shown to display antisocial behavior, which could be adopted by their children. a lack of parental stimulation and affection during early development leads to high levels of cortisol with the absence of balancing hormones such as oxytocin which disrupts and overloads the child's stress response systems, which is thought to lead to underdevelopment of the child's brain that deals with emotion, empathy and ability to connect to other humans on an emotional level. according to dr. bruce perry in his book the boy who was raised as a dog, "the brain needs patterned, repetitive stimuli to develop properly. spastic, unpredictable relief from fear, loneliness, discomfort, and hunger keeps a baby's stress system on high alert. an environment of intermittent care punctuated by total abandonment may be the worst of all worlds for a child." parenting styles parenting styles are related to the environmental influences children experience that can have an impact on their diagnosis of aspd. the four parenting styles demonstrate the main approaches of raising children and their outcomes that lead into adulthood. authoritarian- authoritarian parenting styles involve more strict rules than any other parenting style with higher consequences if rules are disobeyed. authoritarian parents set high expectations for their children and may cause children to later develop rebellious behavior, low self-esteem, aggression, and resentfulness. permissive- permissive parenting styles involve a more relaxed attitude towards rules that are less enforced than any other parenting style. permissive parents tend to allow more freedom for children to make their own decisions which can lead to impulsivity, lack of self-control, and a lack in acknowledgment of boundaries later in life. neglectful- neglectful parenting styles tend to have little to no rules for children to follow and may even withhold basic needs for child development. parents who display neglectful behavior are less involved than with any other parenting style and can cause children to develop mental health issues, a withdrawal from emotions, and delinquent behavior authoritative- authoritative parenting styles involve guidelines and expectation as well as support and understanding. authoritative parents tend to have more balance within their parenting style compared to the other parenting styles and parent in a way that children understand not only what the rules are, but why they’re important. individuals who were raised by authoritative parents tend to be more self-confident, responsible, successful, and have a greater chance at developing positive coping skills. having a healthy, safe, stable/consistent, understanding, and attentive parenting style in an environment with positive role models and influences in home as well as out in the community help to ensure more positive behavior for children and a decrease in aspd symptoms. childhood trauma aspd is highly correlated with emotional and physical abuse in childhood. physical neglect has a significant correlation to aspd. the way a child bonds with the parents in early life is important. poor parental bonding due to abuse puts children at greater risk for developing antisocial personality disorder. there is a significant correlation with paternal overprotection and people who develop aspd. studies have shown that non-abused (especially in childhood) individuals are less likely to have aspd. forms of childhood trauma/abuse that victims with aspd have encountered include physical and sexual abuse, neglect, coercion, abandonment or separation from caregivers, violence in a community, acts of terror, bullying, or life threatening incidents. as seen in other forms of mental illness such as: post-traumatic stress disorder (symptoms of upsetting/terrifying memories of traumatic events), reactive attachment disorder (little to no response regarding emotional triggers), disinhibited social engagement disorder (roaming off with people you don’t know without caregivers being informed), dissociative identity disorder (disconnection from self or environment), etc. there have also been correlations with the listed mental illnesses, such as: individuals with ptsd have higher rates of aspd. cultural influences the sociocultural perspective of clinical psychology views disorders as influenced by cultural aspects; since cultural norms differ significantly, mental disorders such as aspd are viewed differently. robert d. hare has suggested that the rise in aspd that has been reported in the united states may be linked to changes in cultural mores, the latter serving to validate the behavioral tendencies of many individuals with aspd.: 136 while the rise reported may be in part merely a byproduct of the widening use (and abuse) of diagnostic techniques, given eric berne's division between individuals with active and latent aspd – the latter keeping themselves in check by attachment to an external source of control like the law, traditional standards, or religion – it has been suggested that the erosion of collective standards may indeed serve to release the individual with latent aspd from their previously prosocial behavior.: 136–7 there is also a continuous debate as to the extent to which the legal system should be involved in the identification and admittance of patients with preliminary symptoms of aspd. controversial clinical psychiatrist pierre-édouard carbonneau suggested that the problem with legal forced admittance is the rate of failure when diagnosing aspd. he contends that the possibility of diagnosing and coercing a patient into prescribing medication to someone without aspd, but is diagnosed with aspd, could be potentially disastrous. but the possibility of not diagnosing aspd and seeing a patient go untreated because of a lack of sufficient evidence of cultural or environmental influences is something a psychiatrist must ignore; and in his words, "play it safe". conduct disorder main article: conduct disorder while antisocial personality disorder is a mental disorder diagnosed in adulthood, it has its precedent in childhood. the dsm-5's criteria for aspd require that the individual have conduct problems evident by the age of 15. persistent antisocial behavior, as well as a lack of regard for others in childhood and adolescence, is known as conduct disorder and is the precursor of aspd. about 25–40% of youths with conduct disorder will be diagnosed with aspd in adulthood. conduct disorder (cd) is a disorder diagnosed in childhood that parallels the characteristics found in aspd and is characterized by a repetitive and persistent pattern of behavior in which the basic rights of others or major age-appropriate norms are violated. children with the disorder often display impulsive and aggressive behavior, may be callous and deceitful, and may repeatedly engage in petty crime such as stealing or vandalism or get into fights with other children and adults. this behavior is typically persistent and may be difficult to deter with threat or punishment. attention deficit hyperactivity disorder (adhd) is common in this population, and children with the disorder may also engage in substance use. cd is differentiated from oppositional defiant disorder (odd) in that children with odd do not commit aggressive or antisocial acts against other people, animals, and property, though many children diagnosed with odd are subsequently re-diagnosed with cd. two developmental courses for cd have been identified based on the age at which the symptoms become present. the first is known as the "childhood-onset type" and occurs when conduct disorder symptoms are present before the age of 10 years. this course is often linked to a more persistent life course and more pervasive behaviors, and children in this group express greater levels of adhd symptoms, neuropsychological deficits, more academic problems, increased family dysfunction, and higher likelihood of aggression and violence. the second is known as the "adolescent-onset type" and occurs when conduct disorder develops after the age of 10 years. compared to the childhood-onset type, less impairment in various cognitive and emotional functions are present, and the adolescent-onset variety may remit by adulthood. in addition to this differentiation, the dsm-5 provides a specifier for a callous and unemotional interpersonal style, which reflects characteristics seen in psychopathy and are believed to be a childhood precursor to this disorder. compared to the adolescent-onset