Rather than relying on intuition or subjective judgement as did Freud and many other neo-Freudians, trait theorists used objective measurements to examine their constructs. The use of factor analysis was a major breakthrough in the trait approach and Raymond Cattell was the first to make the use of this to reduce the lists of traits to a smaller number. This marked the beginning of the search to discover the basis structure of personality.
This essay will discuss the issues surrounding the use of personality measures such as Eysencks personality questionnaire (EPQ) and Costa and Mc Crae’s Big Five model (NEO-PIR) to predict behaviour. Cattell’s 16PF hasn’t had much of an impact but personality measures that followed such as Eysenck’s personality questionnaire, who claimed that 3 types/ supertraits, Extraversion, Neuroticism and Psychoticism, make up the basic structure of personality, and Costa and mc Crae’s Big Five Model measuring Openness, Conscientious, Extraversion, agreeableness and Neuroticism, have received a high level of support.
The personality factors are found cross-culturally, in children as well as adults and specifically for Eysencks model in identical twins raised apart, evidence which seems to demonstrate that the observed personality differences are stable across time and have a genetic basis, although the underlying heritability estimate used in studies has been questioned by Plomin.
Nevertheless, trait measures have great practical applications; they have been embraced by psychologists from almost every perspective and used by professionals working in a wide variety of settings, such as in the workplace and the education system etc, and are used to make important judgements about an individual’s behaviour in different situations. Employers have used scores from personality tests to make hiring and promotion decisions for many years (Roberts and Hogan, 2000).
The methodology used to identify the dimensional structure of personality traits, factor analysis, is often challenged for not having a universally-recognized basis for choosing among solutions with different numbers of factors. More than one interpretation can be made of the same data factored the same way, and factor analysis cannot identify causality. However, some of the most common criticisms of trait theory centre on the fact that traits are often poor predictors of behaviour. While an individual may score high on assessments of a specific trait, he or she may not always behave that way in every situation.
This was highlighted by Walter Mischel (1968, 1973) who stimulated a huge debate that raged until the early 1980s, concerning whether personality traits predict behaviour. At the heart of this debate was the questioning of the stability of traits across situations, known as the ‘personality paradox’. He demonstrated with his CAPs model that there is a complex interaction between situations and enduring individual personality differences, however the effects of many variables still have to be examined.
Mischel criticised how personality measures were interpreted and used, demonstrating that on average personality measures statistically account for only around 10% of the variance observed in behaviour, therefore 90% is due to something other than the effect of personality. This reflects the fact that many factors contribute to any one piece of behaviour, such as: the characteristics of the specific situation, the person’s mood at that time, competing goals, etc. However an argument in trait theories defence is in regard to the . 30, . 40 correlation co-efficient. How high does a correlation have to be before its considered important?
Research by Funder and Ozer (1983) looked at social psychological findings often cited for their “important” findings and found that they had similar co-efficient of . 36 and . 42. In their defence trait theorists argue that researchers often fail to provide a strong link between traits and behaviour is because they don’t measure behaviour correctly, only measuring one behaviour. As an alternative researchers can aggregate data, one study looked at trait measures of aggression and the number of aggressive acts students preformed, not only on one day but over the course of two weeks and found a correlation of . 1 between the aggregated measure and the trait score (Wu and Clarke, 2003). Burger (2008) states that when all the complex influences on our behaviour are taken into account we probably should be impressed that personality psychologists can explain even 10%. Mischels criticism has had beneficial effects in work settings, with the use of multiple measures of personality such as, psychometric assessments, interviews, individual and group tasks used together as an assessment package to prevent overreliance on the psychometric tool.
Furthermore, Mischels views led researchers to look very critically at their methodologies, admitting that measures were often weak and the selection of which traits to study was sometimes inappropriate (Funder, 1999,2001). Today most psychologists agree that the person and the situation react to determine behaviour ( Maggnusson, 1990) and Swan and Seyle (2005) conclude their review on Mischels work by saying that there are still instances where it is helpful to make distinctions between personal and situational determines of behaviour.