Eysenck's Personality Theory for Offending

• Eysenck (1947) suggests that offending behaviour arises from personality traits that predispose us to offending.
• Eysenck (1947) proposed that behaviour could be represented along 2 dimensions; introversion-extraversion (E) and neuroticism-stability (N). The two dimensions combined to form a variety of personality characteristics or traits. Eysenck later added a third dimension of psychoticism-sociability (P).
• According to Eysenck personality traits are innate and come about through the type of nervous system we inherit. He suggested that the criminal personality had an innate biological basis.
• Eysenck (1964) argued that criminal behaviour was influenced by personality characteristics which are linked to biological differences between individuals.
• Extraversion has a biological basis within the ascending reticular activating system (ARAS) which is responsible for the general arousal of the nervous system. It is connected to the cerebral cortex and governs the arousal of the brain.
• Extraverts have an underactive nervous system which means they constantly seek excitement and stimulation and are likely to engage in risk-taking behaviours.
• Neuroticism has a biological basis within the limbic system which controls our emotional reactions and is easily triggered.
• Neurotic individuals have a high level of reactivity in the sympathetic nervous system, which means they quickly respond to situations of threat (fight or flight). This means they tend to be nervous, jumpy and overanxious and their behaviour is often difficult to predict.
• With psychoticism, hormone levels are implicated, particularly testosterone, which is associated with aggressive behaviour. In addition levels of the neurotransmitter serotonin are also affected.
• Psychotic individuals are suggested to have higher levels of testosterone making them more prone to aggression, as well as having less emotional responses, such as a lack of guilt or remorse.
• Eysenck suggested that criminals are more likely to have characteristics which are high in extraversion (E) neuroticism (N) and psychotic (P) traits.
• According to Eysenck criminals are usually higher in personality traits like P, N, E.
• Psychotic traits suggest criminals are more prone to aggression and lack empathy.
• Neurotic traits suggest criminals are unstable and prone to overreact to situations of threat. 
• Extraversion traits suggest criminals seek more arousal and are more likely to engage in dangerous activities.
• In Eysenck’s theory, personalities are linked to offending behaviour via socialisation processes. These are ways that we interact with the environment around us, and how we are taught behaviour from being a young child.
• Eysenck saw offending behaviour as developmental immaturity associated with immediate gratification. 
• The notion that personality can be measured is one that is central to Eysenck’s theory. He developed the Eysenck Personality Questionnaire (EPQ), which is a psychological test that determines personality along the PNE dimensions.
• An individual who scores highly on measures of extraversion, neuroticism and psychoticism are more likely to engage in criminal behaviour.
• Eysenck’s theory offers a way to measure personality through the use of a psychological test (EPQ) which means that criminal personalities can be reliably compared across the population.
• Supporting evidence from Eysenck & Eysenck (1977) suggest that criminals have innate characteristics which make them more likely to behave in particular ways.
• Eysenck & Eysenck (1977) compared 2070 prisoners scores on the EPQ with a group of 2422 controls. On all measures of extraversion, neuroticism and psychoticism, across all age groups, prisoners recorded higher average scores than the control group.
• Eysenck & Eysenck (1977) conducted research which agrees with the predictions of the criminal personality theory, the offenders rated higher than average across all three dimensions on the EPQ.
• McGurk & McDougall (1981) investigated the link between criminality and personality type. 100 students defined as delinquents and 100 students in a control group, completed Eysenck’s personality questionnaire. They found a significant difference in scores suggesting a relationship between personality type and delinquent behaviour.
• Heaven (1996) found that high psychoticism (P) levels were predictive of criminal behaviour.
• One problem with measuring criminal behaviour using the personality test is the high risk of social desirability, individuals may respond in ways they think the researcher wants them to.
• Personality is a very subjective, hypothetical concept to measure, so lacks validity.
• Cultural factors are not considered in Eysenck’s personality theory.
• Bartol & Holanchock (1979) studied Hispanic and African American offenders in a maximum security prison in New York. They found that offenders were less extravert than a control group.
• Farrington et al (1982) conducted a meta-analysis of relevant studies and reported that offenders tended to score higher on measures of psychoticism but not extraversion and neuroticism.
• Kussner (2017) found inconsistent differences on EEG measures in the brains of extraverts and introverts, which casts doubt on Eysenck’s theory.
• It is too simplistic to assume that criminal behaviour is the result of personality characteristics alone.
• Eysenck’s theory of offending behaviour is too deterministic. It is possible to have high extraversion or neurotic scores and not commit crime.
• Moffitt (1993) drew a distinction between offending behaviour that only occurs in adolescence and that which continues into adulthood. She argued that personality traits alone were a poor predictor of how long offending behaviour would go on for.
• Research suggests that Eysenck’s theory is too simplistic and offending behaviour is more likely to be determined by an interaction between personality and the environment.