Forensics - Eysenck's personality theory (psychological approach)

Trait theory

A theory of personality that focuses on identifying, describing, and measuring individual differences in behavioural predispositions. Suggests personalities are made up of traits (or characteristics) and the level you have of these determines your personality

The criminal personality

An individual who scores highly on measures of extraversion, neuroticism and psychoticism has a criminal personality which they have inherited due to the sensitivity of their nervous system. They cannot easily be conditioned, are cold and unfeeling, and are likely to engage in offending behaviour.

Introverts

Enjoy their own company and are quiet and reserved. Most importantly, they think before they act making them less likely to involve themselves in risk-taking behaviours.

Socialisation

Eysenck also argued that personality is linked to socialisation. Criminal behaviour is developmentally immature as it is selfish and concerned with immediate gratification. Through socialisation children are taught how to become more patient and wait for things. Eysenck argued that people with high E and N scores have a nervous system that makes them difficult to socialise and condition

Eysenck's research

Eysenck and his wife Sybil assessed 2070 male prisoners who were compared to a control group of 2422 males. ON measures of E, N and P, prisoners recorded higher scores than the control group - across all age groups - which accords with the prediction of his theory.

Extroverts

Have an under aroused central nervous system and so need more stimulation. This causes them ti actively take part in risk-taking behaviours. They are also less likely to care about the outcomes of their behaviours, not taking punishments personally. They generally enjoy large gatherings and are chatty and impulsive.

- Eysenck's research = questionnaire

His research relied on self report and this could have been hugely influenced by social desirability and so the prisoners want to look as strong as possible and in order to do so they may change their answers

- Eysenck's research = direction of causality

It could be that the prison environment lead to these personality traits. Prisoners believe that they have to be extraverted so that they seem stronger and are less likely to be targeted. They are more likely to be jumpy because they are in an environment with lots of other violent people. They are likely to be less in touch with emotion because a prison environment rewards being 'strong'. These people may not have had these personality traits before they entered the prison. Issues with falsifiability

- too simplistic

It is impossible that one personality type can explain all crime and as a result, this theory becomes quite reductionist, although not as much as the biological approach. It is more likely that a mixture of countless traits that are brought about by deficits in the nervous system as well as poor socialisation are the cause of criminality

The reticular activating system (RAS)

Modulates the level of arousal and activation in the brain. If this residual level is low then a person will seek stimulation from the environment to raise the level.

- generalisability

None of the key studies supporting Eysenck's research was done into female criminals meaning they could have completely different personality types to men. Therefore, the results cannot be generalised both across cultures and to any gender other than men.

Neuroticism

Occurs because of an overly sensitive autonomic nervous system and results in anxiety, insecurity, jumpy, emotional instability. Small threats can trigger their fight or flight response, making them act disproportionately and often resulting in violent bursts.

- Bartol and Holanchock

Studied Hispanic and African-American offenders in NY and divided into 6 groups depending on their criminal history and offence Found all 6 groups were less extrovert than non-criminal control group suggested that the differing results was because their sample was a different cultural group than Eysenck's. This shows that his results cannot be assumed to fit in across all cultures.

+ McGurk and McDougall results

They found significant differences between the two groups. Within the delinquent sample there were students with both high neuroticism and high extraversion, as well as a sub group who scored high on neuroticism, a=extraversion and psychoticism. In the non-delinquent group, however, there were a significant percentage of individuals with low neuroticism and extraversion scores

Biological basis

according to Eysenck, our personality traits are biological in origin and come through the type of nervous system we inherit. So all personality types have an inherited biological basis which makes us predisposed to certain traits. -extraverts have an underactive nervous system --> linked to the level of cortical arousal in the brain.

- Blackburn

concluded that Eysenck's theory of criminality is not well supported despite the fact that there a correlation between criminal behaviour and personality has been obtained --> this does not mean that the criminal personality has caused the criminal behaviour

recipe for criminal personality

extraversion + neuroticism + psychoticism

Psychoticism

high scores relate to vulnerability to mental illness and low scores relate to conscientiousness and agreeableness. Inappropriate emotional expression is a key feature of psychoticism.

Alt Moffit

proposed that there are several types of male offenders based on timing of first offence and how long the offending persists. This influences the personality traits of the person

- Farrington

reviewed Eysenck's study and found that offenders tend to score highly on P measures, but not on E and N. There were also consistent differences between EEG measures (used to measure cortical arousal) between extraverts and introverts, which casts doubt on the physiological basis of Eysenck's theory

- Digman's five factor model

suggests that there are five factors of personality which include openness, agreeableness and conscientiousness which work alongside neuroticisms and extraversion.

+ McGurk and McDougall method

used a personality questionnaire based on Eysenck;s theory and gave it to 100 'delinquent' college students and 100 students who were not delinquent.