0.9 Trait theories of personality  (Page 21/41)

Personality is that which permits a prediction of what a person will do in a given situation. (pg. 2; Cattell, 1950b)

According to Cattell, traits and types are not fundamentally different, but rather opposite extremes of the same statistical measures. The fundamental, underlying traits are known as source traits . Source traits often combine and/or interact in ways that appear, on the surface, to indicate a single trait. For example, in the area of abilities, a unitary intelligence shows itself in good academic performance, such a child who does well in school. Of course, children who do well in school typically do well in most areas, such as math, English, social studies, etc. What may now appear to be a type, a “good student,” can also be described as a surface trait (Cattell, 1950b). As useful as surface traits, or types, may be descriptively, in order to truly understand personality, one must address the source traits. First, however, they must be identified.

Source Traits and Factor Analysis

Cattell used the factor-analytic technique to identify sixteen source traits. He often uses the terms source trait and factor interchangeably. Factor analysis is a statistical technique that determines a number of factors, or clusters, based on the intercorrelation between a number of individual elements. Cattell considered factor analysis to be a radical departure from the personality research that preceded his, because it is not based on an arbitrary choice as to which variables are the most important. Instead, the factor-analytic technique determines the relevant variables, based on the available data:

…the trouble with measuring traits is that there are too many of them!...The tendency in the past has been for a psychologist to fancy some particular trait, such as ‘authoritarianism’, ‘extraversion’, ‘flexibility- vs -rigidity’, ‘intolerance of ambiguity’, etc., and to concentrate on its relations to all kinds of things…individual psychologists lead to a system which tries to handle at least as many traits as there are psychologists! (pg. 55; Cattell, 1965)

When Cattell applied factor analysis to the list of words identified by Allport and Odbert, he identified 16 personality factors, more or less. The reason for saying more or less is that any statistical technique is subject to known probabilities of error. Thus, Cattell considered his sixteen factors to be only an estimate of the number of source traits (Cattell, 1952). As potential source traits were identified that Cattell found difficult to put into words, he assigned them a Universal Index (U.I.) number, so that they could be kept for consideration until they could be studied and explained. Cattell identified as many as forty-two personality factors (see Cattell, 1957). By 1965, when Cattell wrote The Scientific Analysis of Personality , he had included three additional factors to his primary list, giving him nineteen personality factors, and kept thirteen of the remaining factors on his list as yet to be confirmed (though each one had a tentative name).