Eysenck's Biological Trait Theory:

Hans Eysenck assisted in the initial layout of the big-five model which incorporated five core personality traits which are: Openness to experience, Conscientiousness, Extroversion, Agreeableness and Neuroticism (emotional instability). It is suggested that personality is based around these traits. He suggested that by using three main scopes everyone's personality traits could be determined (Bernstein, Cramer, Fenwick, & Fraser, 2008). However, he argued that agreeableness and conscientiousness can be considered as a "higher-order" therefore he has put these two into a category labelled "Psychoticism". This theory has sometime been called the Even Bigger Three or as the Agigantic three (Center & Kemp, 2009).
Eyksenck believed that these four traits worked together to produce predictable trait patterns (Bernstein et. al., 2008).

As mentioned, Eysenck's Biological Trait Theory is based on three main scopes. The first is known as introversion-extraversion, meaning how people react in social situation, introverts tend to be more reserved, quiet and thoughtful whereas extroverts tend to be much more outgoing and like change and excitement. Secondly, Emotionality-stability is the difference between emotional people who can show moodiness, restlessness and anxiety and people who are stable even-tempered and relaxed. Finally, Psychoticism describes what remains from the other factors. It is considered to be a negative aspect of a person's personality. High scores show aloof, insensitive and unempathetic personalities whereas low scores showed sensitivity, nurturing and empathic. He believed that these traits could be traced back to inherited differences in the nervous system (Bernstein et al., 2008). Eysenck stated that because of these biological differences, there are deviations in a person's physiological arousal as well as their sensitivity to stress (Bernstein et al., 2008).

To further this thought, a report was done by David B. Center and Dawn E. Kemp (2002), which looked at children who were antisocial in behaviour. Eysenck's theory on temperament, also known as a three-factor model of personality, suggests that the above mentioned traits can be found in almost all personality studies worldwide, in fact research on the genetics of personality also support these three traits (Center & Kemp, 2002). The EPQ (Eysenck Personality Questionnaire) measure the temperament-based personality traits of not only children but adults as well. This study centers on Eysenck's third trait theory of psychoticism which is thought to be a polygenic trait. This simply means that it is a genetic trait that depends on a large number of genes that of each has a small effect. However, because these effects are small it is additive and therefore depending on the total number inherited, determines the degree of this particular trait that will show in a personality (Center & Kemp, 2002).

Antisocial Personality Disorders are one of the diagnoses that fall under the category of Conduct Disorders and appear to have high psychoticism traits in individuals who have this condition. It is important to note that the EPQ does not diagnose conditions and can not be used to term someone as having a psychosis. Children predisposed to developing anti-social behaviour would show high on the psychoticism trait and those who also show high on the extroversion scale would be predisposed to aggressive and antisocial behaviours. This is due to low cortical arousal, as the person does not learn restraint on certain rule-governed behaviours. An individual would also show high on the neuroticism trait since this would add an irrational characteristic and overly emotional behaviours. Due to this, the antisocial behaviour thought needed all three personality traits on a high scale (Center & Kemp, 2002). Finally, the Personality Questionnaire's Lie scale also created by Eysenck is designed to measure socially expected or acceptable responses to a variety of questions. A low score on this scale indicates indifference to these socially accepted responses. Antisocial individuals normally score quite low on this scale (Center & Kemp, 2002).

‚ÄčThe result of this study showed that Eysenck's anti-social behaviour hypothesis was clearly accurate with regards to children and youth. Using his trait theory and questionnaires could possibly help identify children who are at risk of this behaviour during early school years. At this time prevention methods should be considered. Information about temperament-based personality traits may be useful for creating personalized interventions for students who already are identified with behavioural or emotional disorders (Center & Kemp, 2002).