Eysenck proposed a theory of personality based on biological factors, arguing that individuals inherit a type of nervous system that affects their ability to learn and adapt to the environment
Eysenck didn't believe that offending behaviour is inherited directly, but rather a consequence of the type of nervous system we inherit which determines our personality
An individual who scores highly in measures of extraversion, neuroticism and psychoticism cannot be easily conditioned and are cold, unfeeling and likely to engage in offending behaviour
Argues that biological predispositions towards certain personality traits combined with conditioning and socialisation during childhood create personality
Interactionist approach may be more valid than either a biological or environmental theory alone
Links with the diathesis stress model of behaviour which argues for a biological predisposition combining with an environmental trigger for a particular behaviour
Our legal system is based on the premise that criminals have personal and moral responsibilities for their crimes, and only in extreme cases, such as a diagnosis of mental illness, can someone claim they were not acting under their own free will
Contemporary theories of personality such as the 5 factor model suggest that other personality dimensions are important, such as openness to experience, agreeableness and conscientiousness
A neurotic-extravert may not necessarily become an offender, depending on their psychological make-up in relation to the other dimensions, which is a weakness of Eysenck's theory
Eysenck's theory presents a dilemma in the field of criminality
Our legal system is based on the premise that criminals have personal and moral responsibilities for their crimes, but the notion of a criminal personality suggests they are pre-determined to commit crime, raising ethical issues about what society does with these people