How well does trait theory help us understand individual differences?
In order to assess how well trait theory helps us to understand individual differences with reference to personal construct theory, it is necessary to define both theories and consider their relative strengths and weaknesses.
Trait theory is concerned with the measurement of traits, which are habitual patterns of behavior, feeling and thought, in order to promote our understanding of why people behave differently in different situations. Trait theorists argue that traits are relatively stable over time and influence behavior. (Butt, 2004, p.1) Eysenck argued that personality can be described using the three major traits of neuroticism, extroversion and psychotism, (Butt, 2004, p.2) although other trait theorists have developed a higher number of traits. Questionnaires such as Eysenck’s Personality Inventory (EPI) are used to develop psychometric inventories, which measure personality traits and therefore enable us to predict how a person might behave in a particular situation. Trait theorists believe that traits are biologically determined and genetically inherited (Butt, 2007, p.46). For example, Eysenck’s study of soldiers in combat (1947, cited in Butt, 2007, p.46) enabled him to identify his two, unrelated, personality dimensions of extraversion and neuroticism. He argued that these dimensions were ‘behavioural expressions of differences in biologically-based temperament’ (Butt, 2007, p.46) Eysenck believed that the level of extraversion and neuroticism displayed by individuals is due to differences in cortical and autonomic arousal. (Butt, 2004, p.4)
A key strength of trait theory is that it is commonly and easily understood due to its similarity to the ways in which people assess and describe each other in everyday life (Butt, 2007, p.47). In addition to this, measurement tools, such as Eysenck’s EPI and Cattell’s 16PF, provide objective measures of personality, allowing...