The issue of human violence is also a major topic within the academic discipline of psychology. As biosocial theorists do, psychologists focus on how individual characteristics may interact with the social environment to produce a violent event. However, rather than focus on the biological basis of crime, psychologists focus on how mental processes impact individual propensities for violence. Psychologists are often interested in the association between learning, intelligence, and personality and aggressive behaviour. In this section of the report, we briefly review some of the major psychological perspectives that have attempted to explain violent behaviour. These perspectives include the psychodynamic perspective, behavioural theory, cognitive theory and personality theory. We will also explore the possible relationship between mental illness and violence.
The psychodynamic perspective is largely based on the groundbreaking ideas of Sigmund Freud. A detailed discussion of Freud’s theory of psychoanalysis is beyond the scope of this report. It is sufficient to note that Freud thought that human behaviour, including violent behaviour, was the product of “unconscious” forces operating within a person’s mind. Freud also felt that early childhood experiences had a profound impact on adolescent and adult behaviour. Freud, for example, believed that conflicts that occur at various psychosexual stages of development might impact an individual’s ability to operate normally as an adult (Bartol, 2002). For Freud, aggression was thus a basic (idbased) human impulse that is repressed in well-adjusted people who have experienced a normal childhood. However, if the aggressive impulse is not controlled, or is repressed to an unusual degree, some aggression can “leak out” of the unconscious and a person can engage in random acts of violence. Freud referred to this as “displaced aggression” (see Englander, 2007; Bartol, 2002).
It is interesting to note that Freud himself did not theorize much about crime or violence. The psychoanalyst who is perhaps most closely associated with the study of criminality is August Aichorn. Unlike many of the sociologists of his day, Aichorn felt that exposure to stressful social environments did not automatically produce crime or violence. After all, most people are exposed to extreme stress and do not engage in serious forms of criminality. Aichorn felt that stress only produced crime in those who had a particular mental state known as latent delinquency. Latent delinquency, according to Aichorn, results from inadequate childhood socialization and manifests itself in the need for immediate gratification (impulsivity), a lack of empathy for others, and the inability to feel guilt (Aichorn, 1935).
Since Aichorn’s early work, psychoanalysts have come to view violent criminals as “iddominated” individuals who are unable to control their impulsive, pleasure-seeking drives (Toch, 1979). Often because of childhood neglect or abuse, violence-prone individuals suffer from weak or damaged “egos” that render them unable to deal with stressful circumstances within conventional society. It is also argued that youth with weak egos are immature and easily led into crime and violence by deviant peers (Andrews and Bonta, 1994). In their most extreme form, underdeveloped egos (or superegos) can lead to “psychosis” and the inability to feel sympathy for the victims of crime (see DiNapoli, 2002; Seigel and McCormick, 2006). In sum, psychodynamic theories depict the violent offender as an impulsive, easily frustrated person who is dominated by events or issues that occurred in early childhood.
The most significant criticism of the psychoanalytic perspective is that it is based on information derived from therapists’ subjective interpretations of interviews with a very small number of patients (see Englander, 2007). In other words, the theory has not yet been subject to rigorous scientific verification. Nonetheless, it is important to stress that basic psychodynamic principles have had a major impact on the subsequent development of criminological thought. For example, many other theories of violence have come to stress the importance of the family and early childhood experiences. Similarly, a number of sociological and criminological theories stress that violent criminals are impulsive and lack empathy for others (see the discussion of self-control theory below). Many of these theories are discussed in upcoming sections of this report.
Behaviour theory maintains that all human behaviour – including violent behaviour – is learned through interaction with the social environment. Behaviourists argue that people are not born with a violent disposition. Rather, they learn to think and act violently as a result of their day-to-day experiences (Bandura, 1977). These experiences, proponents of the behaviourist tradition maintain, might include observing friends or family being rewarded for violent behaviour, or even observing the glorification of violence in the media. Studies of family life, for example, show that aggressive children often model the violent behaviours of their parents. Studies have also found that people who live in violent communities learn to model the aggressive behaviour of their neighbours (Bartol, 2002).
Behavioural theorists have argued that the following four factors help produce violence: 1) a stressful event or stimulus – like a threat, challenge or assault – that heightens arousal; 2) aggressive skills or techniques learned through observing others; 3) a belief that aggression or violence will be socially rewarded (by, for example, reducing frustration, enhancing self-esteem, providing material goods or earning the praise of other people); and 4) a value system that condones violent acts within certain social contexts. Early empirical tests of these four principles were promising (Bartol, 2002). As a result, behavioural theory directly contributed to the development of social learning theories of deviance (differential association theory, sub-cultural theory, neutralization theory, etc.). These theories, among the most important and influential of all criminological theories, are subject to a detailed discussion in the section of this report entitled Social Learning and Violence (see below).
Cognitive theorists focus on how people perceive their social environment and learn to solve problems. The moral and intellectual development perspective is the branch of cognitive theory that is most associated with the study of crime and violence. Piaget (1932) was one of the first psychologists to argue that people’s reasoning abilities develop in an orderly and logical fashion. He argued that, during the first stage of development (the sensor-motor stage), children respond to their social environment in a simple fashion by focusing their attention on interesting objects and developing their motor skills. By the final stage of the development (the formal operations stage), children have developed into mature adults who are capable of complex reasoning and abstract thought.
Kohlberg (1969) applied the concept of moral development to the study of criminal behaviour. He argued that all people travel through six different stages of moral development. At the first stage, people only obey the law because they are afraid of punishment. By the sixth stage, however, people obey the law because it is an assumed obligation and because they believe in the universal principles of justice, equity, and respect for others. In his research, Kohlberg found that violent youth were significantly lower in their moral development than non-violent youth – even after controlling for social background (Kohlberg et al., 1973). Since his pioneering efforts, studies have consistently found that people who obey the law simply to avoid punishment (i.e., out of self-interest) are more likely to commit acts of violence than are people who recognize and sympathize with the fundamental rights of others. Higher levels of moral reasoning, on the other hand, are associated with acts of altruism, generosity and non-violence (Veneziano and Veneziano, 1992). In sum, the weight of the evidence suggests that people with lower levels of moral reasoning will engage in crime and violence when they think they can get away with it. On the other hand, even when presented with the opportunity, people with higher levels of moral reasoning will refrain from criminal behaviour because they think it is wrong.
Another area of cognitive theory that has received considerable attention from violence researchers involves the study of information processing. Psychological research suggests that when people make decisions, they engage in a series of complex thought processes. First they encode and interpret the information or stimuli they are presented with, then they search for a proper response or appropriate action, and finally, they act on their decision (Dodge, 1986). According to information processing theorists, violent individuals may be using information incorrectly when they make their decisions. Violence-prone youth, for example, may see people as more threatening or aggressive than they actually are. This may cause some youth to react with violence at the slightest provocation. According to this perspective, aggressive children are more vigilant and suspicious than normal youth are – a factor that greatly increases their likelihood of engaging in violent behaviour. Consistent with this perspective, research suggests that some youth who engage in violent attacks on others actually believe that they are defending themselves, even when they have totally misinterpreted the level of threat (Lochman, 1987). Recent research also indicates that male rapists often have little sympathy for their own victims, but do in fact empathize with the female victims of other sexual offenders. This finding suggests that, because of information processing issues, some offenders can’t recognize the harm they are doing to others (Langton and Marshall, 2001; Lipton et al., 1987).
The psychological concept of “personality” has been defined as stable patterns of behaviour, thoughts or actions that distinguish one person from another (see Seigel and McCormick, 2006: 180). A number of early criminologists argued that certain personality types are more prone to criminal behaviour. The Gluecks (Glueck and Glueck, 1950), for example, identified a number of personality traits that they felt were associated with violence, including self-assertiveness, defiance, extroversion, narcissism and suspicion. More recently, researchers have linked violent behaviours to traits such as hostility, egoism, self-centredness, spitefulness, jealousy, and indifference to or lack of empathy for others. Criminals have also been found to lack ambition and perseverance, to have difficulty controlling their tempers and other impulses, and to be more likely than conventional people are to hold unconventional beliefs (see Atkins, 2007; Capara et al., 2007; Costello and Dunaway 2003; Johnson et al., 2000; Sutherland and Shepard, 2002; Miller and Lynam, 2001).
The Multiphasic Personality Inventory (MMPI) and the Multidimensional Personality Questionnaire (MPQ) have frequently been used to assess the personality characteristics of young people. The use of these scales has consistently produced a statistically significant relationship between certain personality characteristics and criminal behaviour. Adolescents who are prone to violence typically respond to frustrating events or situations with strong negative emotions. They often feel stressed, anxious and irritable in the face of adverse social conditions. Psychological testing also suggests that crime-prone youth are also impulsive, paranoid, aggressive, hostile, and quick to take action against perceived threats (Avshalom et al., 1994).
There is considerable debate about the causal direction of the personality-violence association. On the one hand, some scholars have argued that there is a direct causal link between certain personality traits and criminal behaviour. However, others maintain that personality characteristics interact with other factors to produce crime and violence. For example, defiant, impulsive youth often have less-than-stellar educational and work histories. Poor education and employment histories subsequently block opportunities for economic success. These blocked opportunities, in turn, lead to frustration, deprivation, and ultimately, criminal activity (Miller and Lynam, 2001).
Research suggests that some serious violent offenders may have a serious personality defect commonly known as psychopathy, sociopathy or anti-social personality disorder. Psychopaths are impulsive, have low levels of guilt and frequently violate the rights of others. They have been described as egocentric, manipulative, cold-hearted, forceful, and incapable of feeling anxiety or remorse over their violent actions. Psychopaths are also said to be able to justify their actions to themselves so that they always appear to be reasonable and justified.
Considering these negative personality traits, it is perhaps not surprising that recent studies show that psychopaths are significantly more prone to violence compared with the normal population. Furthermore, the research evidence also suggests that psychopaths often continue with their criminal careers long after others have aged out of crime. It has been estimated that approximately 30 per cent of all prison inmates in the United States are psychopaths. More recent projections, however, place this estimate closer to ten per cent. However, psychopaths are particularly over-represented among chronic offenders. Indeed, it is estimated that up to 80 per cent of chronic offenders exhibit psychopathic personalities. In sum, research suggests that psychopaths have a significantly higher likelihood of violence than others do. However, experts also stress that not all psychopaths become violent. In fact, the majority of people convicted of violent crimes in Canada and the US do not have a psychopathic personality (see reviews in Edens et al., 2001; Lykken, 1996).
A recent meta-analysis conducted by Edens and his colleagues (2007) summarizes juvenile recidivism data in relation to psychopathology. The authors searched and coded both published and unpublished studies completed between 1990 and 2005. The studies they reviewed include an even split between American and Canadian samples (with one additional sample from Sweden). The results of their ambitious project reveal that a juvenile diagnosis for psychopathy is a strong predictor of future violence in adulthood. The findings further demonstrate that psychopathy is significantly related to both general and violent recidivism, but only weakly associated with sexual recidivism. Interestingly, the data also reveal that psychopathy is a weaker predictor of violent recidivism among more racially diverse samples.
Psychologists think that a number of early childhood factors might contribute to the development of a psychopathic or sociopathic personality. These factors include having an emotionally unstable parent, parental rejection, lack of love during childhood and inconsistent discipline. Young children – in the first three years of life – who do not have the opportunity to emotionally bond with their mothers, experience a sudden separation from their mothers, or see changes in their mother figures are at particularly high risk of developing a psychopathic personality.
Another major area of psychological inquiry involves the possible relationship between intelligence and crime. Criminologists working in the early 20th century often argued that intelligence is strongly associated with criminal behaviour. People with low intelligence, they argued, were much more likely to engage in crime and violence than people with high intelligence were. Support for this hypothesis was garnered from studies that directly compared the IQ scores of adolescents with IQ scores derived from the general population. In general, these pioneering studies reported that the IQ scores of delinquents were significantly lower than the IQ scores of normal controls (Goddard, 1920; Healy and Bronner, 1926).
Simplistic notions that low intelligence causes crime and delinquency often led to disastrous results. For example, in the 1920s, the governments of British Columbia and Alberta passed “negative eugenics” laws that called for the sterilization of people thought to possess low intelligence or other negative psychological characteristics. It is important note that, but for the disapproval of the Catholic church, such sterilization laws would also have come into effect in both Ontario and Quebec. Under such laws, which remained in effect until the 1970s, over 5,000 people in Canada were approved for sterilization. Most of these people were arbitrarily diagnosed as having “mental defects.” Finally, in 1999, the courts decided that the Alberta and BC governments had acted falsely and victims subsequently agreed to an $82 million settlement (see Seigel and McCormick, 2006: 183).
Much of the early work on the link between IQ and crime has been dismissed as overly simplistic and as unsubstantiated owing to poor research designs. However, the issue of a possible association between intelligence and violence has persisted into this century. Much of the contemporary debate centres on whether intelligence is biologically based or the product of environmental conditions. Nature theory holds that intelligence is genetically determined and that low IQ directly causes violent and criminal behaviour. Nurture theorists, on the other hand, argue that intelligence is determined by the quality of the social environment – particularly during childhood – and is not a product of genetic inheritance. Intelligence, they maintain, is largely determined by the quality of the parental bond, the level of intellectual stimulation received during early childhood, the nature of local peer-group relations, and the quality of neighbourhood schools. Therefore, nature theorists argue that, if IQ scores are indeed lower among violent criminals, this likely reflects differences in environmental or cultural background, not differences in biological makeup (Rogers et al., 2000).
Nature theory also came under attack in the late 1920s and early 1930s when new studies determined that the IQ-crime relationship was not as strong as initially expected. For example, Slawson (1926) found that although adolescent offenders tended to score lower on verbal intelligence tests, they had normal scores on measures of nonverbal intelligence. These results highlighted the possibility that IQ tests may be culturally biased. Similarly, Edwin Sutherland, one of the founding fathers of modern criminology, provided evidence that observed differences in IQ scores often stemmed from problems with testing methods rather than actual differences in intelligence (Sutherland, 1931). After being condemned by Sutherland as an unproductive line of inquiry, research on the IQ-crime relationship disappeared from the criminological literature for several decades.
In a controversial article that appeared in the late 1970s, Travis Hirschi and Michael Hindelang reviewed existing data on the intelligence-crime relationship and concluded that IQ is a stronger predictor of crime and violence than many other demographic characteristics are – including social class (see Hirschi and Hindelang, 1997). Since the appearance of this article, a large number of other international studies have emerged that the support the existence of the IQ-violence relationship (Piquero, 2000; Lynam et al., 1993; Denno, 1985). Many of these studies, however, suggest that the IQ-crime relationship is quite weak. For example, an extensive review by the American Psychological Association found only a small relationship between intelligence and criminal behaviour. By contrast, in The Bell Curve, James Q. Wilson and Charles Murray (1994) conclude, after an extensive review of the research evidence, that there is a very strong correlation between IQ and crime and that people with low IQs are more likely to commit crimes, get caught, and be sent to prison. Similarly, a recent study by Piquero (2000) found that low scores on intelligence tests were among the strongest predictors of violent behaviour and could be used to distinguish between violent and non-violent offenders.
While some scholars maintain that there is a direct link between intelligence and criminality, others believe that there is only an indirect association. Some argue, for example, that low intelligence leads to poor school performance. Poor school performance, in turn, directly contributes to criminal behaviour. Wilson and Hernstein summarize this argument when they state that “[a] child who chronically loses standing in the competition of the classroom may feel justified in settling the score outside, by violence, theft and other forms of defiant illegality” (Wilson and Herstein, 1985: 148). Critics have responded to this position by maintaining that there are many other factors, besides intelligence, that contribute to success in school. These factors include family support for academic achievement, the quality of teachers and the school environment, the nature of the curriculum, and the degree of student engagement.
The debate over the exact nature of the intelligence-crime relationship is nowhere near to being solved. Most experts agree, for example, that the measurement of IQ is extremely problematic. Furthermore, the distinct possibility that IQ tests are both culturally biased and class-biased greatly undermines the validity of previous research. Finally, even if we accept previous research results at face value, intelligence-based explanations cannot begin to explain major patterns of criminal behaviour. IQ scores, for example, do not come close to explaining why men are much more violent than women. Similarly, people do not become more intelligent as they age. Thus, IQ-based theories cannot account for the fact that most offenders age out of crime and violence (see Seigel and McCormick, 2006).
A recent survey of more than 6,000 respondents from 14 countries found that approximately ten per cent of the adult population suffers from some form of mental illness – ranging from depression to schizophrenia (Seigel and McCormick, 2006). Rates of mental illness may be even higher among youth. For example, one study found that one in five children and adolescents residing in Ontario suffer from a significant mental health disorder.1 Leschied (2007) notes that cross-national research has also documented a 20 per cent mental illness rate among children between zero and 16 years of age. The most common disorders among youth include depression, substance abuse and conduct disorder (Osenblatt, 2001). Research also suggests that mental health issues may put young people at risk of engaging in violent behaviour. For example, after an extensive review of the literature, Monohan (2000: 112) noted that “[n]o matter how many social and demographic factors are statistically taken into account, there appears to be a greater than chance relationship between mental disorder and violent behaviour. Mental disorder is a statistically significant risk factor for the occurrence of violence.”
Research suggests that depression, a relatively common disorder among youth, may be related to aggression. For example, one recent study documented that affective disorders are related to aggression at both home and school. This study is important because other studies have found a link between depression and both property crime and substance use, but not violence (see Englander, 2007). However, the authors of this study do note that they only focused on minor forms of aggression, not serious violence (Pliszka et al., 2000). Interestingly, a number of studies have found that while minor depression is related to an increased probability of minor criminality, major bipolar depression is not at all related to serious violent behaviour. Indeed, major depression may be too crippling a disorder to permit someone to form intent and act out in a violent manner (see Modestin et al., 1997). Similarly, some experts have suggested that youth suffering from affective disorders are actually more likely to withdraw and harm themselves than to act violently towards others (Hillbrand, 1994).
Additional research suggests that particular types of mental illness – including schizophrenia – are more associated with violent behaviour than others are (see Lescheid, 2007). For example, people who suffer from paranoid delusions that others are trying to harm them, or feel that their minds are being controlled by outside forces, are more vulnerable to periodic episodes of rage and violence than are those who do not have these symptoms (Monahan, 1996; Berenbaun and Fujita, 1994). Studies have also found that up to 75 of juvenile murderers suffer from some form of mental illness – including psychopathy and schizophrenia (Rosner, 1979; Sorrells, 1977). Another study followed 1,000 English children from birth to their 21st birthday and found that only two per cent of the sample met the DSM-III diagnostic criteria for mental illness. However, this two per cent was responsible for 50 per cent of the violent incidents that were documented during the study period (see Arsenault et al., 2000).
In sum, research gives tentative support for the idea that mental disturbance or illness may be a root or underlying cause of violent behaviour. It is extremely important to note, however, that some scholars suggest that this relationship may be spurious. In other words, the same social conditions that produce violent behaviour – including parental neglect, child abuse, violent victimization, racism, peer pressure and poverty – may also cause mental illness (for discussions about the co-morbidity of violence and mental illness see Durant et al., 2007; Leischied, 2007). Studies also suggest that most people with severe mental illnesses do not engage in serious violence or criminality (Cirincione et al., 1991). It is also interesting to observe that, at the societal level, rates of violent crime have actually decreased at the same time that mentally ill populations have been de-institutionalized.
Substance abuse – including alcoholism – has now been formally recognized as a mental illness. Research has also established that there is a strong positive correlation between levels of substance abuse and violence. For example, a Corrections Canada survey of over 6,000 inmates, many of them violent offenders, found that 48 per cent admitted to using illegal drugs at the time of their offence (Seigel and McCormick, 2006). Similarly, a recent US study found that over 80 per cent of people arrested for violent crimes tested positive for illegal drugs at the time of their apprehension (Feutcht, 1996). Furthermore, numerous cross-national surveys of prison inmates reveal that the vast majority were under the influence of drugs and/or alcohol at the time of their offence (Innes, 1988).
It is hypothesized that alcohol and drugs can impact violence in three ways. First of all, alcohol and drugs may have psychopharmacological effects that impair cognition and subsequently increase the likelihood of aggressive behaviour. Many have argued, for example, that the physiological impact of substance use serves to reduce social inhibitions and thus frees or enables people to act on their violent impulses. Others, however, have argued that this “disinhibition effect” is culturally specific. Anthropologists have shown, for example, that the social effects of alcohol vary dramatically from country to country. In some nations, alcohol intoxication is related to violence, in others it is not. Is it possible that the effect of alcohol and drugs are socially defined? In some societies, people may come to believe that there is a strong relationship between intoxication and violence. If so, some people may come to use alcohol and drugs as an excuse or justification for their violent behaviour. Studies do suggest that people are more forgiving of people who engage in violent acts while intoxicated and are less forgiving of people who engage in violence while sober (see review in White, 2004).
A second way that substance abuse may increase violence is by increasing economic need. Many drug addicts, for example, engage in violent crimes (including robbery) in order to gain enough money to support their habits. Violence is also related to competition between drug traffickers. Indeed, any lucrative drug trade may attract ruthless individuals and gangs who are willing to resort to violence in order to control markets (territories) or ensure the repayment of drug debts. Drug traffickers may also draw the attention of other predatory criminals who specifically target them for robbery because they carry large volumes of cash (and drugs) and cannot report their victimization to the police (Wortley and Tanner, 2007).
Over the past 100 years, psychological perspectives on violence have had a major impact on crime control and crime prevention policy. Primary prevention programs that employ psychological principles include strategies that seek to identify and treat personal problems and disorders before they translate into criminal behaviour. Organizations involved in such primary prevention efforts include family therapy centres, mental health associations, school counselling programs and substance abuse clinics. School administrators, teachers, social workers, youth courts and employers frequently make referrals to these programs. Many argue that the expansion of such psychological services will ultimately reduce the level of violent crime in society (Seigel and McCormick, 2006).
Secondary prevention efforts, on the other hand, provide psychological treatment after a crime has been committed and the offender has become involved in the criminal justice system. Many of these programs are based on social learning principles. Judges often recommend them at the sentencing stage. Furthermore, once inmates enter a correctional facility, they are likely to be subjected to intense psychological assessment to determine their treatment needs. Attendance at such programs may also be a mandatory requirement of probation or parole. Examples of popular psychologically based rehabilitation strategies in Canada include treatment programs for substance abuse, sex offender treatment, anger management training and programs designed to improve cognitive skills (Griffiths and Cunningham, 2000). Over the past few decades, considerable debate has emerged with respect to the relative effectiveness of rehabilitative efforts within corrections. In fact, some critics maintain that “nothing works” with respect to the rehabilitation of chronic offenders (Griffiths and Cunningham, 2000). This issue is subject to a detailed discussion in another report commissioned by the Review of the Roots of Youth Violence.
In sum, as with biosocial theories of crime causation, psychological theories focus on the identification and treatment of individual traits that may predispose people to violent behaviour. As such, psychological theorists have been charged with ignoring larger social forces – including poverty, social inequality, neighbourhood disorganization and racism – that may have a strong impact on violent behaviour. Such factors, however, have been considered by a wide variety of sociological and criminological perspectives on crime. We begin our discussion of these theories in the next section of this report.
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1A “significant” mental health disorder was defined as a condition that is serious enough to warrant outside intervention.