Chapter 13 McCrae and Costa’s Five-Factor Trait Theory 405Fourth, a useful theory has the power to guide the actions of practitioners,
and on this criterion, trait and factor theories receive mixed reviews. Although
these theories provide a comprehensive and structured taxonomy, such a classifica-
tion is less useful to parents, teachers, and counselors than it is to researchers.
Are trait and factor theories internally consistent? The Big Five theory and
research is internally quite consistent, even if there are some (e.g., Eysenck, see
next chapter) who disagree with the number of basic dimensions of personality.
Cross-cultural research tends to lend support for the universality of these five dimen-
sions all over the world, which suggests these are consistent dimensions of human
personality (McCrae, 2002; Schmitt, Allik, McCrae, & Benet-Martínez, 2007; Trull
& Geary, 1997; Zheng et al., 2008). We should point out, however, that cross-
cultural research is not unanimous in its findings supporting the Big Five, partly
due to the difficulties in translating the questions into many different languages. For
instance, the internal reliability of the Big Five Inventory-Agreeableness scale is
only .57 in South and Southeast Asia, suggesting the items are not completely
measuring one dimension among Asians (Schmitt et al., 2007).
The final criterion of a useful theory is parsimony. Ideally, trait and factor
theories should receive an excellent rating on this standard, because factor analysis
is predicated on the idea of the fewest explanatory factors possible. In other words,
the very purpose of factor analysis is to reduce a large number of variables to as
few as possible. This approach is the essence of parsimony.
Concept of Humanity
How do trait and factor theorists view humanity? The Five-Factor theorists
were not concerned with traditional themes such as determinism versus free
choice, optimism versus pessimism, and teleological versus causal influ-
ences. In fact, their theories do not lend themselves to speculation of these
topics. What, then, can we say concerning their view of humanity?
First, we know that factor analysts see humans as being different from
other animals. Only humans have the ability to report data about themselves.
From this fact, we can infer that McCrae and Costa believed that humans pos-
sess not only consciousness, but self-consciousness as well. People are also
able to evaluate their performance and to render reasonably reliable reports
concerning their attitudes, temperament, needs, interests, and behaviors.
Second, McCrae and Costa placed emphasis on genetic factors of per-
sonality. They believe that traits and factors are both inherited and have strong
genetic and biological components and hence are universal. But they also
believed that environment plays a crucial role in shaping a person’s disposi-
tions. Therefore, we rate the Five-Factor model as medium on social influences.
On the dimension of individual differences versus similarities, trait and
factor theories lean toward individual differences. Factor analysis rests on
the premise of differences among individuals and thus variability in their
scores. Thus, trait theories are more concerned with individual differences
than with similarities among people.