in Figure 7.1. Several important characteristics about the trait approach are
depicted in this simple diagram. First, trait psychologists identify a wide rangeof behaviors that can be represented along the continuum. For example,
achievement motivation can range from highly driven persistence at one ex-
treme to indifference at the other. Second, trait psychologists maintain that
we can take any given person and place him or her somewhere along the con-
tinuum. We are all more or less aggressive, more or less friendly, and so on.
Finally, if we were to measure a large group of people and place their scoresat appropriate points along the continuum, we probably would find that the
scores are normally distributed. This means that relatively few people score
extremely high or extremely low, and that most of us fall somewhere towardthe middle of the distribution.
Atrait is a dimension of personality used to categorize people according
to the degree to which they manifest a particular characteristic. The traitapproach to personality is built on two important assumptions. First, trait
psychologists assume that personality characteristics are relatively stable over
time. It would make little sense to describe someone as high in sociability ifthat person loved being around people one day but shied away from social
settings the next. Of course, we all have times we prefer to be alone and other
times we seek out friends. But if we were to examine a given individual ’s be-
havior over a long period of time, we should see a relatively stable level of
sociability. Trait researchers also maintain that someone who is highly socia-
ble today will probably be sociable next month, next year, and many years
down the road. This is not to say that personality does not change. Researchers
find that our personalities continue to develop as we move through adult-
hood and into old age (Bleidorn, Kandler, Reimann, Angleitner, & Spinath,
2009; Roberts & Mroczek, 2008; Roberts, Walton, & Viechtbauer, 2006).
However, these changes are gradual and typically evolve over a period of
many years.
Number
of People
at Each Point
Extremely Low
in TraitAverage Extremely High
in Trait
FIGURE 7.1 Trait Continuum150 CHAPTER 7 The Trait Approach