PSYCHOLOGICAL EXPLANATIONS: EYSENCK’S
THEORY
Psychological explanations of offending behaviour: Eysenck’s theory of the criminal personality
General personality theory
Eysenck developed a theory of personality based on the idea that character traits tend to cluster along three dimensions:
Extraversion/introversion, neuroticism/stability and psychoticism/normality.
Each of these dimensions are normally distributed, so we could expect about 68% of any population to fall within one standard
deviation from the mean.
Biological basis
Eysenck suggested that each trait has a biological basis which is mainly innate; he claimed that 67% of the variance for the traits
is due to genetic factors.
Extraversion – underactive nervous system which means they constantly seek excitement, stimulation and are likely to engage
in risk-taking behaviours. They also tend to not learn from their mistakes.
Neuroticism – tend to be nervous, jumpy and over-anxious, and their general instability means their behaviour is often difficult
to predict
Psychoticism – related to high levels of testosterone, which means that men are more likely to be found at this end of the
spectrum because they have higher levels of testosterone than women.
The criminal personality – Scores highly on measures of extraversion, neuroticism and psychoticism.
The role of socialisation
In Eysenck’s theory, personality is linked to criminal behaviour via socialisation processes. Eysenck saw criminal behaviour as
developmentally immature in that it is selfish and concerned with immediate gratification – they are impatient and cannot wait
for things. The process of socialisation is one in which children are taught to become more able to delay gratification and more
socially oriented. Eysenck believed that people with high E and N scores had nervous systems that made them difficult to
condition. As a result, they would not learn easily to respond to antisocial impulses with anxiety. Consequently, they would be
more likely to act antisocially in situations where the opportunity presented itself.
Measuring the criminal personality
The notion that personality can be measured is one that is central to Eysenck’s theory. He developed the Eysenck Personality
Inventory (EPI), a form of psychological test which locates respondents along the E and N dimensions to determine their
personality type. A later scale was introduced that is used to measure psychoticism
EVALUATION
Evidence supporting Eysenck’s theory
Eysenck and Eysenck (1977) compared 2070 male prisoners’ scores on the EPI with 2422 male controls. On measures of
psychoticism, extraversion and neuroticism, prisoners recorded higher scores than controls which accords with the predictions
of the theory.
Contradictory evidence
Farrington et al (1982) reviewed several studies and reported that offenders tended to score high on P measures, but not for E
and N. there is also very little evidence of consistent difference in EEG measures (used to measure cortical arousal) between
extroverts and introverts, which casts doubt on the psychological basis of Eysenck’s theory.
The idea of a single criminal type
The idea that all offending behaviour can be explained by a single personality type has been heavily criticised. 8 Five Factor
Model of personality suggests that alongside E and N, there are additional dimensions of openness, agreeableness and
conscientiousness. From this perspective, multiple combinations are available and therefore a high E and N score does not mean
offending is inevitable.
Cultural bias
Bartol et al (1979) studied Hispanic and African-American offenders and found that they were less extravert than a non-criminal
control group. Bartol et al suggested that this was because their sample was a very different cultural group than that
investigated by Eysenck, which questions the generalisability of the criminal personality.
Biological determinism
Only in extreme circumstances can a criminal claim that they were not acting under their own free will. Explanations with a
biological basis raise ethical questions about what society does with people who appear innately predisposed to be criminals.
THEORY
Psychological explanations of offending behaviour: Eysenck’s theory of the criminal personality
General personality theory
Eysenck developed a theory of personality based on the idea that character traits tend to cluster along three dimensions:
Extraversion/introversion, neuroticism/stability and psychoticism/normality.
Each of these dimensions are normally distributed, so we could expect about 68% of any population to fall within one standard
deviation from the mean.
Biological basis
Eysenck suggested that each trait has a biological basis which is mainly innate; he claimed that 67% of the variance for the traits
is due to genetic factors.
Extraversion – underactive nervous system which means they constantly seek excitement, stimulation and are likely to engage
in risk-taking behaviours. They also tend to not learn from their mistakes.
Neuroticism – tend to be nervous, jumpy and over-anxious, and their general instability means their behaviour is often difficult
to predict
Psychoticism – related to high levels of testosterone, which means that men are more likely to be found at this end of the
spectrum because they have higher levels of testosterone than women.
The criminal personality – Scores highly on measures of extraversion, neuroticism and psychoticism.
The role of socialisation
In Eysenck’s theory, personality is linked to criminal behaviour via socialisation processes. Eysenck saw criminal behaviour as
developmentally immature in that it is selfish and concerned with immediate gratification – they are impatient and cannot wait
for things. The process of socialisation is one in which children are taught to become more able to delay gratification and more
socially oriented. Eysenck believed that people with high E and N scores had nervous systems that made them difficult to
condition. As a result, they would not learn easily to respond to antisocial impulses with anxiety. Consequently, they would be
more likely to act antisocially in situations where the opportunity presented itself.
Measuring the criminal personality
The notion that personality can be measured is one that is central to Eysenck’s theory. He developed the Eysenck Personality
Inventory (EPI), a form of psychological test which locates respondents along the E and N dimensions to determine their
personality type. A later scale was introduced that is used to measure psychoticism
EVALUATION
Evidence supporting Eysenck’s theory
Eysenck and Eysenck (1977) compared 2070 male prisoners’ scores on the EPI with 2422 male controls. On measures of
psychoticism, extraversion and neuroticism, prisoners recorded higher scores than controls which accords with the predictions
of the theory.
Contradictory evidence
Farrington et al (1982) reviewed several studies and reported that offenders tended to score high on P measures, but not for E
and N. there is also very little evidence of consistent difference in EEG measures (used to measure cortical arousal) between
extroverts and introverts, which casts doubt on the psychological basis of Eysenck’s theory.
The idea of a single criminal type
The idea that all offending behaviour can be explained by a single personality type has been heavily criticised. 8 Five Factor
Model of personality suggests that alongside E and N, there are additional dimensions of openness, agreeableness and
conscientiousness. From this perspective, multiple combinations are available and therefore a high E and N score does not mean
offending is inevitable.
Cultural bias
Bartol et al (1979) studied Hispanic and African-American offenders and found that they were less extravert than a non-criminal
control group. Bartol et al suggested that this was because their sample was a very different cultural group than that
investigated by Eysenck, which questions the generalisability of the criminal personality.
Biological determinism
Only in extreme circumstances can a criminal claim that they were not acting under their own free will. Explanations with a
biological basis raise ethical questions about what society does with people who appear innately predisposed to be criminals.
