The most popular personality theory is the Traits Theory. It assumes that we have broad predispositions, traits, which are responsible for the consistent, distinct and stable patterns of how people behave, feel and think. The higher the level of a particular trait, the greater the tendency to behave in a certain way.
Traits theory can be organised into a hierarchy
The basic idea is that all aspects of human personality have been recorded with language.
Hence, in the 1930s, Allport (and Odbert) went through the entire dictionary picking out 1800 descriptive words to put them into fewer categories. He made a distinction between traits (stable), states (e.g. angry) and activities (e.g. shouting). While he did little research to establish the utility of traits, he classified the trait concept. He believed that traits were heritable (but didn’t do research on it) and showed that people display unique and consistent patterns of trait-related behaviours (yet he didn’t put forward a detailed processing model to explain behaviour).
Cattell used factor analysis on Allport’s words to find 16 factors (of 3 categories: ability, temperament, and motivation (dynamic traits)). As technology was more advanced he was able to use maths and statistics, and he got evidence for his 16 factors through life-span data, observations, tests and questionnaires. However, language changes and thus 45% of the original item-questions (for questionnaires) changed. Many of the 16 factors inter-correlate (overlap) and there is low internal consistency of the items.
Eysenck took Cattell’s work a step further and did a secondary factor analysis on those 16 factors. He found 2 super-factors: Extroversion (trait level: sociable, lively, active, assertive, sensation-seeking) and Neuroticism (already the Greek talked about this concept! Trait level: anxious, depressive, guilt, low self-esteem, shy, moody, emotional), plus the third factor Psychoticism (trait level: aggressive, cold, egocentric, impersonal, impulsive, antisocial, unemphatic creative, tough-minded). Despite supportive data from self-report questionnaires and objective measures (brain activity, heart rate, hormonal levels, genetics), his Three Factor ‘PEN‘ Model ended up being rather unpopular.
Costa and McCrae had the break-through with their ‘Big Five Theory‘ (Openness, Conscientiousness, Extroversion, Agreeableness, Neuroticism). The five personality factors they came up with happen to correlate with Cattell’s 16 factors. There seems to be a remarkable consistency across languages/cultures when translated. EAC are found in most , O and N are less reliable though ( e.g. O contains other elements such as rebelliousness in Dutch). For indigenous languages, translation is not used for tests on the Big Five, instead factor analysis with their own words is carried out.
Costa and McCrae claimed that: Traits are the universal raw material, each trait is possessed to some degree by all of us. They influence psychological development, and have a biological basis; differences in personality are thus due to genetics, brain structure and chemistry. It looks at populations not individuals.
These are rather bold claims; what about the influence of the environment? Why would you just look at the population if you’re ultimately interested in the individual?
Recent research has come up with a ‘Six Factor Theory‘, which adds the trait ‘Honesty/Humility‘ to the Big Five. Sibley looked at NZ data with 24 items for the six factors and found a normal distribution.
And then, there’s the ‘One Factor Theory‘: Intelligence. Maybe a little too reductionist…