What is a Trait Theory?
A trait theory understands personality much as personality is talked about in day-to-day life: a set of personal characteristics or qualities that determines the different ways we behave in different situations.
Trait theory has its origins in Ancient Greece and the work of the Greek physician Galen (2nd Century AD).
At the time, the body was believed to contain four humours (fluids): yellow bile, black bile, phlegm and blood. People were categorised based on a supposed predominance of one or other of the humours. Choleric people - with an excess of yellow bile - were bad tempered. Melancholic people - with an excess of black bile - were gloomy. Phlegmatic people - with an excess of phlegm - were sluggish and unexcitable. And Sanguine people - with an excess of blood (sanguis) - were cheerful and passionate.
Subsequent biological investigations (many centuries later) have disproved the humoral theory, but trait theories still exist in different forms, seeking categories by which to measure and classify people.
The key assumptions of a trait theory are:
- The traits exist across a whole population - no trait is unique to one individual.
- Everyone measures a score for each trait, on a continuum.
Trait theories are an idiographic approach to personality. Most trait theories suggest a set of traits that are fairly stable and consistent across time and space, though some theorists have considered the possibility that traits may be adaptable.
Click to be redirected for our detailed overview of the Eysenck Theory of Personality (Three Factor Model).
The Origins of Contemporary Trait Theory
Gordon Allport (1897-1967)
Gordon Allport was one of the first psychologists to search for a set of basic personality traits. In 19361, he started his search by identifying all the words in a dictionary that described aspects of personality.
Allport found around 18,000 words, which he subsequently analysed and reduced down to those words which referred to stable personality characteristics, rather than temporary states (such as 'flustered') or evaluations of others (such as 'admirable'). At this stage, Allport was still left with 4,000 words referring to stable personality characteristics. Allport next set about grouping words into blocks of synonyms.
Depending on how you group the synonyms, you would achieve between 3 to 16 personality traits using Allport's methodology.
Raymond Cattell (1905-1998)
Raymond Cattell began his search for a small number of basic personality traits with Allport & Odbert's (1936) list of adjectives. In addition, Cattell collected new data from interviews, records describing participants' life histories, and situational observations. From this he prepared preliminary versions of a personality questionnaire, called the 16PF. Eventually, he identified sixteen personality factors.
In his own writing, Cattell referred to these sixteen factors as 'source traits'. He termed groups of similar types of observable behaviour 'surface traits'. Surface traits (such as kindness or friendliness) are assumed to stem from a deeply rooted source trait, which lies at the core of an individual's personality.