The word “forensic” refers to the legal system. Forensic matters include anything related to the application and enforcement of the law, as well as the prosecution of those who violate the law.
Forensic psychology is a relatively new field but it is growing rapidly. Forensic psychologists are involved with many aspects of both civil and criminal law. In matters of civil law, they are involved with competency and disability evaluations, as well as divorce mediation and custody evaluations. In criminal cases, they perform evaluations of the mental state of the defendant (particularly in insanity pleas), and provide expert testimony on relevant psychological factors.
Forensic psychologists may also provide psychotherapy for prison inmates, including specific programs for violent or sexual offenders. They also work directly with law enforcement officials. They screen applicants for the police force and can provide stress management, grief work, and trauma counseling to police officers and other members of law enforcement. Finally, forensic psychologists perform scientific research on such topics as the reliability of children’s testimony, recidivism of sex offenders, impulsivity and aggression, and juvenile delinquency.
Criminal profiling involves the attempt to identify psychological, demographic, and behavioral features of the criminal solely from crime scene evidence. Over the past thirty years or so, criminal profiling has become very popular in law enforcement and is now a widespread practice in many different countries. Its popularity is reflected in the NBC-TV show called Profiler. While there have been a number of attempts to develop theories and systems of criminal profiling, there is very little actual scientific evidence to show that it works. There is even debate among researchers whether criminal profiling can even be scientifically validated if appropriate research were done. In a 1990 study by Anthony Pinnozotto and Norman Finkel, profilers were more accurate than other groups (composed of detectives, psychologists, and students) when identifying demographic characteristics of sex offenders, but less accurate than detectives with regard to homicides.
Any kind of criminal behavior involves a conscious choice to violate the law—if the behavior is accidental or unintentional, it is not criminal. While we know that many environmental factors—including poverty, neighborhood crime rates, social norms, and lack of opportunities for legal employment—contribute to the incidence of criminal behavior, psychological factors also play an integral role in the choice to commit criminal acts.
Not everyone who breaks the law has abnormal psychological traits. Illegal behavior can be motivated by many different factors. However, there are certain psychological features that make some people more likely to engage in criminal behavior than others.
For quite a few decades, the mental health field has attempted to classify and study the personality traits of people most likely to engage in criminal behavior. In other words, they have tried to diagnose the criminal mind. In the latest edition of the official Diagnostic and Statistical Manual of mental disorders, DSM-IV and DSM-IV-TR, the diagnosis of antisocial personality disorder describes people who habitually violate social norms and moral codes.
People with antisocial personality disorder (ASPD) are characterized by callous and exploitive behavior and by a lack of empathy or remorse. According to DSM-IV, a person with this disorder demonstrates a pervasive pattern of disregard for the rights of others as evidenced by at least three of the following criteria: repeatedly engaging in illegal behavior; frequently lying, using aliases, or conning others for personal profit; impulsivity and lack of future planning; irritability and aggressiveness; reckless disregard for the safety of self and others; consistent irresponsibility, with repeated failures to sustain employment or fulfill financial obligations; lack of remorse as evident in indifference to, or rationalization of, hurting, mistreating, or stealing from others. This definition has been criticized, however, for being too focused on behavior instead of personality traits, and for requiring evidence of conduct disorder (a childhood variant of ASPD) before the age of fifteen.
Do Mafia bosses have abnormal psychological traits? Would they be diagnosed with either antisocial personality disorder or psychopathy, the personality disorders characterized by criminal behavior? Their criminal behavior would certainly meet some criteria for both antisocial personality disorder and psychopathy, but the fact that they operate within a subculture distinguishes them from the kinds of criminals that act alone. Within the culture of organized crime, they would probably not be considered psychologically abnormal (Library of Congress).
The concept of psychopathy should be distinguished from the DSM-IV concept of antisocial personality disorder. While diagnosis of antisocial personality disorder is heavily dependent on a record of criminal behavior, psychopathy is more geared to the actual personality traits associated with criminal behavior. Such traits include callousness, superficial and shallow emotion, lack of empathy, irresponsibility, lack of remorse or guilt about harming others, and the tendency to exploit, manipulate and engage in predatory behavior toward others.
Psychopathic prisoners commit more serious and violent crimes than non-psychopathic prisoners. They are also more likely to recidivate (commit another crime) after they are released from prison. Moreover, psychopaths are more likely to commit premeditated rather than impulsive crimes. In Michael Woodworth and Stephen Porter’s 2002 study of 125 prisoners convicted of homicide, the thirty-four psychopathic prisoners were much more likely than the ninety-one non-psychopathic prisoners to have committed premeditated murders (93.3 percent vs. 48.4 percent).
The foremost expert on psychopathy today is a psychologist named Robert Hare (1934–). He has developed an intensive interview to measure psychopathy named the Hare Psychopathy Checklist. His first version was published in 1980 and the revised version (PCL-R) in 1991. The PCL-R is a twenty-item clinical rating scale that is scored based on information from a semi-structured interview and available legal files and medical records. Collateral interviews with someone who knows the subject well are also conducted, as psychopathic individuals are not always reliable informants. Although the maximum possible score is 40, the average scores in both male and female offender populations range from about 22 to 24. Hare uses a cut-off score of 30 to distinguish psychopaths from non-psychopaths. He believes that psychopathy is more of a category than a dimension. This means that someone either is or is not a psychopath. Notably, some other researchers disagree and believe that psychopathic traits fall on a continuum.
Hare estimates that about 50 to 75 percent of the prison population meets criteria for antisocial personality disorder, but only 15 to 25 percent exceed the cut-off point for psychopathy. Hare also estimates that psychopaths make up about one percent of the general population. Thus, psychopathy appears to be a more severe disorder than antisocial personality disorder, but fortunately a less common one.
In Hare’s initial research, he conducted a factor analysis on a large sample of prisoners who had been administered the PCL-R. Factor analysis identifies scale items that cluster together and is used to create subscales of a measure. Two factors were identified, the interpersonal/affective factor (factor 1) and the socially deviant lifestyle factor (factor 2). In 2003, Hare modified his original model with a new 4-factor model. Factor 1 was divided into an interpersonal factor (impression management, grandiosity, pathological lying, and manipulativeness) and an affective factor (lack of remorse, shallow affect, callous/lacking empathy, and failure to acknowledge responsibility). Factor 2 was divided into a lifestyle factor (stimulation seeking, parasitic, lacking goals, impulsive, and irresponsible) and an antisocial factor (aggressive, early behavior problems, serious criminal behavior, engagement in different types of crimes). Other authors have proposed a 3-factor model, dividing Factor 1 as Hare did, but keeping Factor 2 as a behavioral factor. Over the years, new instruments similar to the Hare PCL-R have been developed and have yielded similar factor structures.
The serial killer Ted Bundy (1946–1989), is a perfect example of a psychopath. Handsome, educated, and intelligent, he was actively involved in politics and on close terms with the Washington state governor. Bundy also had long romantic relationships with two women who had little reason to believe he was anything other than what he presented himself to be. Eventually, he admitted to murdering 30 women, but it is likely there were many more victims. He conned, manipulated, and lied to women to get them into his car or some other secluded place, where he would rape, torture, and murder them. He would often approach women wearing a sling, a leg cast, or crutches and ask them to help him carry his belongings. Clearly, his murders were planned and calculated and not at all the result of impulsive outbursts. The dramatic split between his polished public image and his murderous rampages speaks to the callous, sadistic, manipulative, and emotionally disconnected personality traits of a classic psychopath.
One of Hare’s most important findings involves the distinction between Factor 1 and Factor 2. This research suggests that psychopathy is made up of two relatively distinct personality traits, antisocial attitudes and antisocial behavior. The first trait reflects cold, callous personality features. The second trait reflects impulsive-aggression and poor behavioral control. These traits may have different causes, differ in their underlying neurobiology, and predict to different types of behavior. Although the two factors correlate at 0.5, suggesting about 25 percent overlap, they are really quite distinct.
Factor 1 includes the emotional and interpersonal aspects of psychopathy, the callous, manipulative and egocentric qualities—in other words, the core personality traits. Factor 1 is correlated with measures of narcissistic and histrionic personality disorder and Machiavellian traits. Factor 1 is also correlated with level of violence, risk of recidivism (repeat crimes), and abnormal emotional processing (low anxiety, low empathy). Factor 1 is not correlated with age, education, or socioeconomic status (SES).
Factor 2 relates to antisocial behavior and the deviant lifestyle. Factor 2 is correlated with measures of substance abuse, criminal behaviors, and antisocial personality disorder. It is also negatively correlated with IQ, education, SES, and age. In other words, people with low SES, education, and IQ are more likely to engage in antisocial behavior. This also means that as people get older, their antisocial behavior decreases. However, core psychopathic personality traits do not appear to be related to age, nor are they necessarily related to other demographic features, such as SES and education.
Antisocial individuals have a good deal of narcissistic features and there is some overlap between the two personality types. Nonetheless, it is important to distinguish between the two. Narcissism is not the same as antisocial personality and many highly narcissistic people do not show antisocial traits. As is shown in Hare’s scale, grandiosity, lack of empathy, and a tendency to use others for one’s own ends are common among psychopathic individuals. And the DSM-IV definition of narcissistic personality disorders lists grandiosity, lack of empathy, and the expectation that others will accommodate to the individual’s desires as criteria for the disorder. In true psychopathy, however, there is little room for interpersonal relationships. Other people simply do not matter; they are solely means to an end. In narcissism, on the other hand, there is often a strong emphasis on interpersonal relationships, along with great dependence on others’ approval and validation. Narcissists may be self-obsessed but they are not necessarily cold, cruel, or sadistic. Nonetheless, under the proper conditions, highly narcissistic people can veer into criminal behavior. The desire for riches, fame, and power, along with the grandiose belief of being above the limits of normal people, can lead such individuals to cross over legal and ethical lines.
The majority of criminal behavior is related to impulsivity and impulsive aggression, and intellectual ability is strongly related to impulsivity. A large literature shows a strong correlation between antisocial behavior and lowered performance on a range of cognitive tests. In effect, impulsivity means acting without thinking. Therefore, the ability to reason through situations is a critical component of behavioral control. This entails the ability to consider alternative explanations of events and alternative solutions to problems. Most importantly, one must be able to anticipate future consequences. It is worth noting that reduced cognitive abilities are related to behavioral problems, as measured by Hare’s Factor 2.
Less is known about the relationship between cognitive function and the core psychopathic personality traits of Hare’s Factor 1. Certainly there have been very brilliant psychopaths throughout history, and many have risen to positions of great power. Such people are not impulsive and are very capable of planning ahead. Nonetheless, there is some evidence of subtle cognitive abnormalities in psychopaths, specifically with regard to attention. Several studies have revealed over-focused attention in psychopaths; they only attend to their goal and are relatively unresponsive to peripheral information.
Enron was an enormous energy company based in Texas that quickly rose to national prominence in the 1990s. CEO Ken Lay was a major contributor to political campaigns, and a warm acquaintance of U.S. presidents and other high-level politicians. Enron collapsed in 2001 due to a vast web of fraudulent accounting. This cost tens of thousands of jobs and billions of dollars. Lay, along with executive Jeffrey Skilling and his protegé Andrew Fastow, were all convicted of fraud and sentenced to prison.
Were these men typical psychopaths? Would they meet criteria for antisocial personality disorder? Although we can only guess outside of an in-person clinical interview, it is more likely that all three men fell victim to their own narcissism. Seduced by the power, wealth, and glory of their enormous success, they chose to keep their profits growing, even if they had to cross ethical and legal lines in the process. The life savings of thousands of Enron employees became less important than their own ambition. We can also question the societal values that place such priority on financial success, ultimately encouraging the kind of financial misbehavior uncovered in the Enron scandal.
While the greed of some corporate titans might seem psychopathic, it is unlikely they would meet the full criteria for antisocial personalitry disorder (iStock).
There is clear evidence that criminals tend to age out. Most serious and violent crimes are committed by people under the age of forty. According to Cathy Widom and Michael Maxfield, the core age for criminal behavior is from twenty to twenty-five. Moreover, Factor 2 on Hare’s Psychopathy Checklist, which measures antisocial behavior, is negatively correlated with age. Thus, there is a general reduction of impulsive-aggressive and reckless behavior as people get older. This reduction may also relate to the fact that older people have less energy and physical vigor than younger people. However, planful criminal behavior that makes minimal physical demands on the criminal is less likely to diminish with age. As Hare’s data shows, the psychopathic personality traits (Factor 1) do not decrease with age but are stable over time. That is why psychopathic people who have underlings to carry out their antisocial behavior, such as murderous dictators and kingpins of organized crime, can continue to engage in criminal activity well into their eighties.
There is a large literature on the risk factors for criminal behavior. Research points to a multitude of risk factors, including genetic, cognitive, personality, family, and community influences. Of note, however, this research does not distinguish between antisocial behavior and psychopathic personality traits.
Environment plays an extremely important role in the development of antisocial traits. It is no coincidence that most of the people in jail for violent crimes come from lower socioeconomic levels and disadvantaged communities. Even though we are continually learning more about the biological and genetic contributions to antisocial behavior, it is critical to keep in mind that environment greatly shapes all aspects of human behavior. Environment even shapes much of human biology, including gene expression.
The explosion in neurobiological research of the past few decades has shed more and more light on the neurobiology underlying antisocial behavior. We now know much more about the brain areas involved in antisocial behavior, the kinds of biological conditions that contribute to antisocial behavior, and even genes that raise the risk of antisocial behavior.
Current research shows that nature (genes and biology) and nurture (environment) interact throughout life. Our genes prime us toward certain personality traits and psychological abilities (for example, intelligence, verbal skills, risk tolerance). In effect, our genes set the parameters, or the outer limits, of our mental capacities. Our environment then determines whether we will meet our potential or fall below it. Our environment also tells us what kinds of behaviors are socially acceptable and likely to be rewarded or punished. Moreover, when both genetic/biological and environmental risk factors are present, antisocial traits are significantly amplified. For example, children with both biological vulnerabilities and high-risk environments show much more severe antisocial traits than children with either biological or environmental vulnerabilities alone.
The relationship between individual and social risk factors is critically important. Poverty, poor education, inadequate community institutions, lack of appropriate social support systems, antisocial peers, and dangerous and violent neighborhoods can all have a devastating effect on an adolescent’s social and psychological development. Together, these factors greatly raise the risk of the child growing up to engage in criminal behavior.
In a 2002 study, Magda Stouthamer-Loeber and colleagues examined risk and protective factors for severe and persistent delinquency over a six-year period in a sample of 871 boys. In particular, they looked at the impact of the general socioeconomic status (SES) of the neighborhood. Neighborhood SES was based on information from the 1990 census, including data on median household income, number of single-parent families, and percentage of families below the poverty line. Neighborhoods were divided into four groups: high, medium, and low SES, and low SES with the majority of residents in public housing. In the boys aged thirteen to nineteen there was a clear relationship between neighborhood SES and criminal behavior. The results showed that 17.7 percent of the high SES group, 32.4 percent of the medium SES group, 41.7 percent of the low SES group, and 69.4 percent of the low SES/public housing group engaged in serious delinquent behavior. In other words, boys from the lowest SES neighborhood were almost four times more likely to engage in serious delinquent behavior than boys from the highest SES neighborhood.
Criminal behavior involves the violation of the law, which in most cases also involves violation of social norms. However, in subcultures in which criminal behavior is socially acceptable, such as adolescent gangs, terrorist groups, and organized crime, an individual’s participation in criminal behavior may be less a function of abnormal psychology than of the identification with and desire to fit into a social group. In other cases, people join violent social groups not out of free choice but because of coercion from the particular group or a perceived need for protection from other violent, predatory groups. In disadvantaged, low SES neighborhoods where violent gangs are more likely to flourish, this can have a devastating effect on the social development of young people, and young men in particular.
Teen gangs are typically well-structured social groups with clear codes of acceptable behavior. When trying to understand gang members’ behavior, it is probably more useful to consider the social environment where gangs tend to flourish than to focus on the psychological traits of individual gang members. In other words, it is likely that gang members become violent because they have been socialized to become that way in the gang (iStock).
Faulty, inept or abusive parenting, parental psychopathology (such as depression), and antisocial behavior in the siblings all increase the risk of a child engaging in antisocial behavior.
One obvious fact about criminal statistics is that criminals are predominantly male. In a 2001 study by Cathy Widom and Michael Maxfield, there was a 2.5–1 male to female ratio for any arrest among a sample of 667 young adults. For violent crime, the male to female ratio increased to 6.7–1. In FBI statistics for 1998, women accounted for 22 percent of all arrests, 8 percent of convicted violent felons, 23 percent of property felons, and 17 percent of drug felons. Moreover, when female criminal behavior does occur, it is often in the company of a male.
Finally, female antisocial behavior may be more strongly linked to trauma and abuse. For example, in a Widom and Maxfield’s study, abused women were 227 percent more likely to commit a violent crime than non-abused women, while the rate of violent crime only increased by 17 percent for abused men vs. non-abused men. We cannot know the extent to which this gender difference is due to cultural or biological influences. Given the predominance of male criminals across history and cultures, however, it is likely there is a strong biological component, possibly involving male hormones such as testosterone.
There is considerable evidence that a history of child abuse increases the likelihood of criminal activity in adolescence and adulthood. In their 2001 study, Cathy Widom and Michael Maxfield examined the arrest records of 1,575 individuals, including 908 individuals with documented histories of child abuse or neglect and 667 non-abused controls who were matched to the first group for age, sex, race, and family socioeconomic status. All abuse cases occurred between 1967 and 1971 when the children were eleven years of age or younger. By 1994, 27.4 percent of the abused/neglected group had arrests as a juvenile compared to 17.2 percent of the non-abused group. In addition, 41.6 percent had arrests as adults compared to 32.5 percent of the non-abused group, and 18.1 percent had been arrested for a violent crime vs. 13.9 percent of the non-abused group. Thus, abused children were about 60 percent more likely to be arrested as a juvenile and 30 percent more likely to be arrested as an adult than non-abused children.
It is important to stress that the majority of abused children do not grow up to develop antisocial traits. According to some estimates, in fact, as much as one-third of abused children grow up without significant psychological damage. However, the risk of the child developing antisocial traits increases with more severe abuse and with the presence of other risk factors, such as poverty, poor schools, etc.
There are a number of psychological characteristics that raise the risk of later criminal behavior. Poor cognitive and language ability, problematic and irritable temperament, poor self-control and self-regulation, low self-esteem, and inadequate social and interpersonal skills can all raise the risk of an individual engaging in criminal behavior.
Poor nutrition, inadequate health care, prenatal exposure to illicit substances, and inadequate sleep all interfere with proper brain maturation, hindering social and cognitive development. Moreover, a number of genes have been identified that are associated with reckless, poorly controlled behavior. Finally, biologically based mental conditions, such as attention deficit disorder and various learning disorders, also interfere with behavioral control and raise the risk of criminal behavior.
One study found that violent men whose heart rate went down during an argument with their wives had higher levels of aggressive-sadistic tendencies (iStock).
Psychopathic individuals appear to be hyporeactive to emotional stimuli. In other words, the emotional parts of the brains do not react as strongly to emotional stimuli as the same parts of the brain in healthy people and even in non-psychopathic prisoners. Likewise, a large body of literature shows that psychopaths have difficulty processing emotional information. Compared to non-psychopathic criminals, they are less able to identify emotions as expressed in vocal tone, facial expression, or spoken sentences. Moreover, they may be particularly insensitive to sadness. Also, the two halves of their cortex, the left and right hemispheres, are not well coordinated during cognitive tasks, and the left hemisphere may be less active than is typical for most people. This suggests that the emotional processes of the right hemisphere are not well coordinated with the verbal processes of the left hemisphere. This difficulty making sense of emotion may relate to the lack of empathy that is characteristic of psychopaths.
Modern research has taught us a good deal about the neurobiology of antisocial traits. It is important, however, to distinguish the neurobiological traits associated with impulsivity and those associated with psychopathy, as they may be quite different. We know that people with high levels of impulsivity and impulsive aggression have less 0 activation in their orbital frontal region. This part of the frontal lobe lies just above the eye sockets and is associated with behavioral control. Some researchers suggest that the orbital frontal cortex links planned behavior with memories of punishment. In other words, the person is more likely to reason, “Oh oh, if I hit this person, I might get hit back.” When the orbital frontal cortex is compromised, the fear of punishment is not strong enough to deter the person from impulsive and reckless actions.
There is also evidence of decreased function in the dorsolateral frontal cortex in impulsive aggression. This area is involved in abstract and complex thought, abilities that are often compromised in impulsive-aggressive people. The serotonin system may also be abnormal in impulsive people. The neurotransmitter serotonin also seems to be involved in behavioral control. People with hyperactive serotonin systems may have over-controlled behavior, while the opposite appears to be true with impulsive people, whose serotonin system is underactive.
We may be able to distinguish psychopathic individuals from impulsiveaggressive individuals by measuring their heartbeat when they are angry. In an important 1995 study by John Gottman and colleagues, 61 wife batterers were divided into two groups according to their heart rate during disagreements with their wives. One group showed lowered heart rates during the disagreement, while the heart rates of the other group went up. In other words, the first group became less aroused during the disagreement rather than more aroused.
Compared to the second group, however, the low-heart-rate men displayed more verbal aggression and anger during the discussion, while their wives showed more sadness and possibly more fear. Further, more of these men had a history of violence outside the family and of witnessing domestic violence as children. Finally, they scored higher on measures of antisocial and aggressive-sadistic personality disorder than the high-heart-rate men. In sum, the low-heart-rate batterers looked more typically psychopathic, while the high-heart-rate batterers looked more impulsive-aggressive.
To summarize, biological research into psychopathy has shown us that psychopaths have overly focused attention, are under-responsive to emotions, and become less aroused instead of more aroused when they are angry. How might we understand these findings? One possibility is that psychopathic individuals grew up in very threatening and violent environments. As a consequence, they learned to down-regulate their emotional responses and narrow their attention in order to focus solely on getting what they want and on surviving in a brutal, dog-eat-dog world. Unfortunately, what may have started out as a way to survive brutality ultimately serves to perpetuate it.
There is growing evidence of a genetic basis for antisocial traits. In a 2008 twin study by Mats Forman and colleagues, all 1,480 twins born in Sweden from 1985-1986 were administered the Youth Psychopathic Traits Inventory. By comparing correlations between identical and fraternal twins, the authors concluded that psychopathic traits have a strong genetic basis and that this is especially true for the impulsive/irresponsible subscale versus the grandiose/manipulative and callous/unemotional subscales. Some authors estimate that genetics account for 40 to 50 percent of antisocial behavior. However, it is difficult to know for sure how much of antisocial behavior is due to genetics and how much is due to environment. For one, estimates of heritability (or genetics) rely heavily on twin studies, in which the genetic differences are carefully measured but the environmental differences are not. Moreover, twins tend to have quite similar environments. Thus, environmental contributions are probably underestimated.
One gene that has received a fair amount of attention is known as monoamine oxydase A (MAOA) and codes for an enzyme (also called MAOA) involved with the metabolism of key neurotransmitters involved with emotion and behavior, specifically serotonin, norepinephrine, and dopamine. A variant of this gene reduces MAOA enzyme activity and is more common in antisocial individuals than in controls. It is likely, however, that this gene codes for impulsivity rather than antisocial behavior per se. Another gene, called-G1438A, is related to the 5HT2A subtype of the serotonin system. One variant (or polymorphism) of this gene, known as the G-allelle, is associated with increased rule breaking in adolescent boys, as shown in a 2009 study by S. Alexandra Burt. The other variant, known as the A-allelle, is associated with lower levels of rule breaking, and incidentally, lower levels of popularity with peers. In other words, boys with the G-allele were both bigger rule breakers and more popular.
Because of the criminal nature of the drug industry, competition between rival drug dealers is often a horribly violent affair, resulting in countless drug-related deaths. Some analysts believe that drugs should be made legal in order to reduce crime. Others believe legalizing drugs would only i2 increase drug addiction (iStock).
Drug addiction is strongly correlated with impulsivity and many people with antisocial traits also abuse illicit substances. Unfortunately, drug abuse and addiction also promote antisocial behavior. For one, drug addiction can destroy an addicted individual’s ability to hold a job, removing the means to pay for the drug. In this situation, drug addicts may turn to crime in order to obtain the money needed to pay for their drug. Common forms of criminal activity include robbery, drug dealing, and prostitution. Secondly, many drugs of abuse impair judgment and impulse control, which increases the likelihood of reckless and criminal acts. In fact, it has been estimated that 55 percent of car accidents and more than 50 percent of murders involve alcohol intoxication. Thirdly, most Western countries outlaw the most common drugs of abuse. Unfortunately, this fails to erase demand for the drugs. Consequently, the market for illicit drugs goes underground and becomes the domain of criminals. Competition within the illicit drug trade has led to a tremendous amount of violence, dating back many decades.
Most violent crime involves impulsive aggression. It is no surprise, then, to find that, on average, violent criminals have many of the characteristics associated with impulsive aggression. They are largely male, young, have problems regulating their aggression, and tend to have lower IQs, less education, and lower SES than the general population. They are also more likely to have childhood histories of physical abuse and neglect. Cognitively, they have difficulty anticipating the consequences of their actions, and tend toward a narrow, rigid, and essentially paranoid interpretation of others’ intentions. Ambiguous gestures are interpreted as threatening and hostile, setting off a hair-trigger aggressive reaction. Non-impulsive violent criminals are more likely to have psychopathic traits; that is, they have the callous, exploitive, and unemotional traits of a psychopath.
Perpetrators of nonviolent crimes, such as property and drug offenses, are obviously less violent than violent criminals. Likewise, they have less difficulty with controlling their aggression. These crimes are also associated with impulsivity, however, and nonviolent criminals, on average, have many features associated with impulsivity, such as younger age, lower IQ, and less education. Proportionately, females are considerably more likely to be convicted of a nonviolent than a violent crime. About 20 percent of nonviolent felons are female according to FBI statistics, whereas only about 8 percent of violent felons are female.
Perhaps because of the extremely damaging effects of child sexual abuse, forensic psychologists have put a fair amount of effort into studying sexual molesters of children. Child molesters tend to be older than other criminals and are probably not as impulsive, although there is likely a subset of highly impulsive child molesters. Most child molesters use bribery, manipulation, and seduction to access their victims, although a sizeable proportion use instrumental force, that is, only enough force to attain their goals. Although there is a small fraction of highly violent child molesters, the vast majority are not violent. While most child molesters are heterosexual males who molest girls, the men who molest boys tend to have far more victims, hundreds or thousands in some instances. In general, the majority of child molesters have only a few victims, while a small fraction with persistent pedophilic tendencies can molest hundreds or thousands of children over a lifetime.
All professionals who work with child molesters are struck by the variety within this population. There is clearly no one type of child molester. In a 2008 article, Robert Prentky, Raymond Knight, and Austen Lee proposed several subtypes of child molesters, based on their own clinical experience and the research literature. The most important distinction is between fixated and regressed child molesters. Fixated child molesters have a long-standing sexual attraction to pre-pubescent children. They have a higher rate of reoffending, show greater sexual arousal to pedophilic stimuli, and have a much larger number of victims than other types of child molesters.
Regressed child molesters are not primarily pedophilic, but turn to children for sit-uational reasons. They might have impulse control problems, poor social skills, psychopathic tendencies, or a substance abuse disorder. A second dimension involves social competence. Some child molesters turn to children because they have inadequate social skills to engage with adults. Together, this results in four categories: high fixation/low social competence; high fixation/high social competence; low fixation/low social competence; and low fixation/high social competence. Child molesters are then further differentiated according to the amount of contact, physical injury, and sadism involved.
Male offenders against boys seem to be quite different from male offenders against girls. Nonetheless, it is unlikely that homosexual pedophiles have much in common with other homosexuals, that is, adult men who are sexually attracted to other adult men. For one, a good percentage of homosexual pedophiles also molest girls, over 60 percent in one study. Secondly, in an important 1988 study by William Marshall and colleagues, about two-thirds of sexual offenders against boys showed greater sexual 4 arousal to pictures of adult women than they did to pictures of adult men.
Adults who sexually molest children have a disproportionately high rate of sexual abuse in their own childhoods. Child molesters are more likely to have a childhood history of sexual abuse than are nonsexual offenders and even sex offenders against older victims. According to a 1995 by Christopher Bagley and colleagues of a community-based, nonforensic sample, men who reported multiple events of sexual contact in their own childhood were almost forty times more likely to report having sexual contact with children than men who reported no sexual abuse in childhood (7.7 percent vs. 0.2 percent).
In a 2007 study by Lisa Cohen and colleagues, data on 392 sexual offenders against children and 209 sexual offenders against adults were taken from the New York State Sex Offenders Registry. Offenders against children were older, more likely to have male victims or victims of both sexes, and less likely to use force or a weapon. They also had less invasive offenses and were less likely to have sexual intercourse with their victim. In other words, compared to adult rapists, child molesters are older, less violent, and less focused on female victims.
Sometimes children are called upon to testify in court. This is particularly relevant in child abuse cases. How reliable is a child’s testimony? Research shows that children are just as capable as adults at recalling specific events accurately. Their memory, however, is highly susceptible to suggestion. In other words, they are easily led to recall things that did not actually happen, and then become convinced their new memories are accurate. Because of this, the reliability of the testimony of children is heavily dependant on the interviewer’s technique. Interviewers who ask leading questions, repeat the same question numerous times, or communicate a preference for one answer over another are more likely to extract inaccurate testimony from children. Additionally, children are easily intimidated by adult authority figures, particularly those in uniform, and may say what they believe the adult wants to hear rather than what they actually remember. The Kelly Michaels case is a tragic illustration of what can happen when child testimony is misused.
Most white-collar crimes take a higher level of planning, cognitive sophistication, and occupational success than other crimes. Accountants, bookkeepers, or investment bankers who siphon off tens of thousands of dollars tend to do so over a period of months or years, all the while hiding their behavior from their colleagues. Moreover, their ability to attain a position of responsibility in the first place generally speaks to better impulse control, planning, and ability to delay gratification than is found in the typically impulsive criminal. Likewise, white-collar criminals tend to be more educated and come from a higher SES background than other criminals. We can also speculate that many white-collar criminals have a high degree of narcissistic traits and find the allure of the money and the status that it can bring overwhelming. An inflated sense of entitlement dampens their guilt at stealing from other people. Consequently, they fail to inhibit their illegal behavior. However, some white-collar criminals may also have antisocial or psychopathic traits, but are simply less impulsive than other types of criminals.
Kelly Michaels was a 26-year-old nursery school worker who fell victim to the widespread hysteria about child molestation—particularly in day care centers—that occurred in the 1980s and early 1990s. In 1988, Michaels was convicted of 115 offenses related to child sexual assault, all of which allegedly took place at the nursery school where she worked. Based on the testimony of 20 of her three- to five-year-old charges, she was sentenced to 47 years in prison. The children’s allegations included bizarre and highly improbable sex acts, such as spreading peanut butter on their genitals and violating them with silverware and Lego blocks. The absence of physical signs of abuse in any of the children failed to influence the outcome.
Michaels spent five years in prison before her case was overturned on appeal. Examination of the interviews of the children revealed highly suspect techniques. Children were badgered, cajoled, and bribed into giving the desired responses. The children were simply too young to understand that they were being pressured to say things that were not true. Following cases like this, researchers turned their attention to the various ways children’s testimony can be distorted and corrupted.
Luckily, serial killers are quite rare but they tend to get intensive media coverage when they come to public attention. Unfortunately, this may serve to encourage the behavior. It is hard to determine exactly when a murderer becomes a serial killer. One definition includes any one who commits at least four murders. Serial killers tend to act alone or with an accomplice and they generally kill strangers. Importantly, they kill for their own psychological gratification, rather than for money, power, or political purposes. Most derive sexual pleasure from their crimes, which tend to be ritualistic 6 and sadistic.
Forensic psychologists say that serial killers are motivated by the sense of absolute power over their victims, and that they spend a good deal of time fantasizing about and planning their crimes. Not surprisingly, most serial killers are profoundly emotionally disturbed and many report traumatic and painful childhoods. In one small study from 1988, 69 percent reported a history of alcoholism in their family and 74 percent reported psychological abuse in childhood. Nonetheless, serial killers do not tend to be very impulsive. In fact, the most successful serial killers can effectively plan their crimes and escape capture for decades.
A popular theory among criminal profilers is that serial killers can be divided into two types according to their crime scene evidence. The first type is organized and has a planful, thought-out approach to the crimes. These serial killers position the body, attempt to hide the body, tamper with the evidence, and take the weapon with them. Disorganized criminals are less careful and methodical. They use an improvised murder weapon, leave the body uncovered, leave a trail of clothing to the murder scene, and leave the victim’s belongings scattered about. The two types of serial killers are also assumed to use different modes of torture, rape, and murder.
Surprisingly, this theory has had little scientific evidence to back it up. In a 2004 article, David Canter and colleagues tested the organized/disorganized classification by studying the records of one hundred different serial killers. They found that all of the serial killers were predominantly organized in their approach. This makes perfect sense, given that serial killers are repeat murderers who manage to evade arrest for years. Disorganized features were less common, but present to some degree in almost all subjects.
The authors suggested a new way of classifying serial killers, dividing them into four new categories: those concerned with mutilation, execution, sexual control, or plunder. The first type mutilates the victim’s body, often after death. The second type executes their victims quickly after they are finished with them. The third type sexually tortures the victims while they are alive, presumably giving the killer a sense of complete control over another person. The fourth type ransacks and plunders the victims’ belongings.
The relationship between mental illness and criminal behavior is a complicated one. Can mentally ill people be judged by the same standards as the rest of the population? Is it fair to punish someone who is incapable of rational thought the same way as someone who makes a conscious and rational decision to perform a criminal act? On the other hand, should we excuse people from accountability just because they are psychologically disturbed? How do we balance the right of the individual for fair treatment with the right of society for protection from antisocial acts? The legal system addresses these philosophical questions through the concepts of competence, culpability, and mitigating factors.
Serial killers tend to get intense media coverage. Both Jeffrey Dahmer and John Wayne Gacy are well known serial killers. Dahmer was arrested in the early 1990s, and Gacy in the late 1970s. Gacy was a mild mannered, apparently law abiding man who sexually assaulted and murdered at least 30 young men. Interestingly, Gacy was also an artist, and painted bizarrely innocent and childlike pictures of nature scenes and of children’s cartoons, such as Disney’s seven dwarves. The planned and organized nature of his crimes, as well as the psychopathic split between respectability in public and murderous perversion in private, is characteristic of serial killers. Dahmer, on the other hand, showed extreme psychological disturbance from early on and had problems with alcoholism and sexual offenses from a young age. Both men died in prison.
The issue of mental competence comes up far more frequently than the problem of mental illness and culpability. When people are competent, they are intellectually and emotionally capable of acting in their own best interest. In a criminal setting, this may mean being competent to stand trial or to participate in one’s own defense. On a civil level, this may mean competent to manage one’s own finances, make medical decisions, or otherwise manage one’s own affairs. When someone is deemed incompetent to care for him or herself or to perform some specific task, a legal representative is charged with making decisions for the incompetent person and is legally responsible to act in the person’s best interest.
In order for someone to be responsible, or culpable, for a criminal act, it is necessary to have criminal intent. In other words, the person must have intentionally chosen to act in a criminal way. As intention is a psychological state—and one that is not always easy 8 to prove—the individual’s mental state is relevant to the proof of criminal intent. Therefore, someone who is mentally ill, or “insane,” may not have the psychological wherewithal to have criminal intent. Such a person may not understand what he or she is doing, or may not be able to control himself or herself. While most people agree that profoundly mentally ill people should not be held to the same standard of accountability as the rest of the population, it is difficult to tell when mental illness justifiably excuses criminal behavior. Can someone be mentally ill and still culpable? How do we define mental illness?
Not guilty by reason of insanity is a legal defense that means that the individual is not criminally responsible for an act he or she committed because he or she is unable to form criminal intent due to insanity. Insanity is a legal term that is quite different from the clinical term. In the United States, the legal definition of insanity varies from state to state. Most states specify that a person must be unable to appreciate the nature and implications of their behavior or to understand that it was morally wrong. Other states include the inability to resist one’s impulses is the definition of insanity. Some states have no insanity defense at all. Under federal law, an insane person cannot “appreciate the nature and quality or the wrongfulness” of the criminal acts.
Although a mentally ill person might not have the psychological capacity to form criminal intent, it is not easy to prove legal insanity (iStock).
Within the last few decades, several states have adopted a guilty but mentally ill verdict. The person is not excused from criminal liability due to insanity, but the court recognizes that mental illness played a role in the crime. Defendants with a guilty but mentally ill verdict are typically remanded to a psychiatric facility or provided with psychiatric treatment while in prison.
Surveys show many people view the insanity defense as an overused tactic exploited by wily criminals and unethical attorneys. Actually, it is used very rarely. An estimated 0.85 percent of cases—that is less than one in 1,000—enter an insanity defense and less than a third of these are successful.
By all accounts, Andrea Yates was a devoted wife, a devout Christian, and a conscientious mother of five small children. Unfortunately, she was also mentally ill. She had been hospitalized several times for psychosis and depression and treated with both antidepressant and antipsychotic medication. She had also twice attempted suicide.
On June 20, 2001, Yates drowned each of her five children in her bathtub and then called the police to report what she had done. Yates claimed that Satan had possessed her and that she needed to kill her children before Satan possessed them as well. If they died while they were still pure they would get into heaven. Otherwise, they would be damned to hell for all eternity.
Although her defense attorneys entered a plea of not guilty by reason of insanity, she was found guilty of murder in a 2002 verdict and sentenced to life imprisonment. Her verdict was overturned in 2006, after it was revealed that one of the prosecution’s expert witnesses had given false testimony. She was then found not guilty by reason of insanity and remanded to a state hospital.
Ted Kaczynski was strange even as a young child. As a six-month-old infant, he suffered a severe allergic reaction, breaking out in hives all over his body. He was in and out of the hospital for the next eight months, separated from his mother. From the time he returned home, he was unresponsive to human interaction. Throughout his childhood, he was extremely shy and painfully averse to human contact, especially with strangers and other children. At the same time he was extremely talented at mathematics, and single-mindedly focused on mastering mathematical problems.
Although he was never diagnosed, this description is certainly suggestive of autism or Asperger’s syndrome. Evidently, his mother considered this possibility as well, and thought of sending him to Bruno Bettelheim, a famous psychoanalyst who specialized in autism.
Kaczynski entered Harvard at age 16, received his Ph.D. in mathematics at the University of Michigan, where he performed brilliantly, and then accepted an academic position at the University of California at Berkeley. Unfortunately, the teaching ¡0 requirements were too much for him; he was simply incapable of managing the interpersonal demands. He left Berkeley and, with his brother, bought a cabin in the Montana woods. He moved in there alone and became increasingly isolated, even cutting off contact from his mother and brother.
As he cultivated the skills to become entirely self-sufficient in the wilderness, he also developed his anti-technology ideology. For years he had become disillusioned with technology and disgusted with human destruction of the natural world. He came to believe that the only way to destroy the “techno-industrial system” was by violent resistance, so in the late 1970s he began a bombing campaign against people linked with technology, including science and engineering professors, computer store owners, and the airline industry. The FBI named him UNABOMB: university and airline bomber.
Over the next 18 years, he sent 16 bombs, injuring 23 people and killing three. In 1995, he published a manifesto, outlining his anti-technology ideology. His brother David recognized Kaczynski’s writings from the manifesto and eventually contacted the FBI. Ted Kaczynski was arrested in 1996. His defense attorneys entered an insanity plea and a court-appointed psychiatrist diagnosed him with paranoid schizophrenia. Kaczynski vigorously rejected this diagnosis, as he did not want his political mission to be dismissed as the rantings of a psychotic man. He plead guilty and was sentenced to life imprisonment without parole but was spared the death penalty because of his brother’s intervention.
Was Kaczynski insane? He almost certainly had a diagnosable psychiatric disorder of some kind. However, he was very clear about his intentions and could rationally argue the merits of his violent acts. Whether or not he was mentally ill, he clearly had criminal intent.
Evidence of psychological disturbance is effectively used to prove mitigating factors. In this case, the defendant is found guilty of the crime, but evidence of mental disturbance is taken into account during sentencing. The burden of proof in these cases is much lower than in an insanity defense.
The remarkable advances in brain imaging technology in recent years have allowed us to discover much about the neurobiology of antisocial personality traits and behavior. For example, on average, violent felons have reduced functioning in the frontal lobe and psychopathic prisoners have under-responsive amygdalas. But what does this mean for responsibility? Are violent criminals less culpable if their brains are abnormal? Are psychopaths less accountable if their brain is less able to process empathy?
Presumably small differences in brain function should not be a “get out of jail free” card. Most psychologists agree that people need to be held accountable to the extent that they have choice and control over their actions. On the other hand, brain abnormalities can be used as evidence of mitigating factors. For example, a nonviolent first offender might receive a lesser sentence if there is evidence of recent head trauma. Most importantly, however, neurobiological research can help with treatment and prevention of antisocial behavior, to protect society from future crimes.
Personality disorders are defined as persistent patterns of thought, emotion, behavior, and interpersonal relationships that are abnormal for the person’s culture and cause distress and dysfunction. With 11 separate personality disorder diagnoses in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), personality disorders are recognized as valid psychiatric conditions. Does the presence of a personality disorder remove culpability for criminal behavior? This is especially of concern, given that some personality disorders are associated with, or even defined by, antisocial behavior. In other words, the use of a personality disorder diagnosis in a criminal defense could lead to absurdly circular thinking: I am not responsible for my criminal behavior because I have antisocial personality disorder, which is defined by my criminal behavior.
Personality disorders differ from psychotic disorders, however, in that the cognitive abnormalities are mild. The problem is more one of motivation and disturbed interpersonal relations. Therefore, there is no reason that a personality disorder would leave someone incapable of forming criminal intent. In sum, the diagnosis has much more relevance for clinical settings than for legal ones.