Trait Measures Do Not Predict Behavior Well
At the heart of this argument is the issue of whether personality or the situation
determines your behavior. Do you act the way you do because of the situationyou are in or because of the kind of person you are? Advocates on one extreme
side of this debate argue that the situation determines behavior almost exclu-
sively. Although these psychologists don ’t assert that everyone acts the same in
a given situation, they often refer to individual differences in behavior as
merely “error variance. ”Advocates on the other extreme claim that stable indi-
vidual differences are the primary determinants of how we act.
Early in this debate some psychologists sought an answer to the person-
versus-situation question by measuring how well personality scores or situa-
tions predict people ’s behavior. Typically, this research found that both the
person and the situation were related to behavior and that knowing about
personality and the situation was better than having information about only
one (Endler & Hunt, 1966, 1968). Unfortunately, this approach has a majorweakness. The results of any such investigation are limited by the type of sit-
uation and the kind of personality variable examined. For example, we can
think of situations in which nearly all people react the same. It would be ab-surd to try to predict whether high- or low-self-esteem people will run outside
when a building catches fire. Although the situation would account for nearly
all of the variance in this case, it also would be incorrect to conclude that dif-
ferences in self-esteem are therefore not related to behavior. If we look at
other behaviors in other situations, such as how people react to criticism, we
will probably find large differences between high- and low-self-esteem people.
Today most psychologists agree that the person and the situation interact
to determine behavior (Funder, 2009). Knowing that a person is high in ag-gressiveness or that a particular situation is frustrating helps researchers pre-
dict behavior less well than knowing both of these facts. Thus, although
people high in aggressiveness may be more prone to act aggressively than
those scoring low on this dimension, and frustrating situations are more likelyto produce aggression than are nonfrustrating situations, researchers would
expect the highest amount of aggression when an aggressive person is placed
in a frustrating situation. This way of looking at the relationship amongtraits, situations, and behaviors is called the person-by-situation approach .
Nonetheless, arguments remain over the validity of using personality trait
scores to predict behavior. Mischel pointed out that personality trait scoresrarely correlate with measures of behavior above the .30 or .40 correlation
coefficient level. This “personality coefficient, ”as it is derogatorily called, sta-
tistically accounts for only about 10% of the variance in behavior. Althoughthese numbers confirm that personality is related to behavior, a considerable
amount of behavior remains that single trait scores do not explain.
There Is Little Evidence for Cross-Situational Consistency
In one of the earliest studies on personality traits, a research team spent sev-
eral years looking at honesty in more than 8,000 elementary school children
(Hartshorne & May, 1928). They measured honesty 23 different ways (lying,
cheating, stealing, and so on) and found an average intercorrelation among166 CHAPTER 7 The Trait Approach