•Is this person often the leader of a group?
•How active and energetic is this person?
•How much does this person crave excitement?
•Is this person usually cheerful?
If we come up with a reasonable system for answering all these ques -
tions, say , on a scale from 1 to 5, we can add up the numbers and assign
a total score for Extraversion. Once we have the answers for a sample ofpeople, we could begin to check the utility of our measure by askingsome simple questions. First, do these items generally agree in the pic -
ture they give of the individual? That is, do people with many close
friends also tend to be energetic and cheerful? This is called internal
consistency , and it provides evidence that the different behaviors or reac -
tions are actually part of a pattern, not just a collection of unrelated ac -
tivities. If the items lack internal consistency , either we have a bad set of
questions or we have misunderstood the nature of Extraversion. Sec-ond, do the scores people get on one occasion parallel the scores theyget at a later time? Are the extraverts of January still extraverts inMarch? This is called retest reliability and demonstrates that what is be-
ing measured is a trait, not a temporary state or mood of the individual.
There is little dispute about any of this. Most psychologists agree
on what kinds of answers we need; the problem comes in deciding howwe should get the answers. How do we know how much a person en-joys parties? We could ask the person for a self-report, but he or shemay never have thought about it, or may lie to us, or may uncon-sciously distort the answer. We could ask friends for peer ratings, butthey may not know how the person really feels and may have seen onlyone side of his or her personality . We could watch the person at a partyand note how much he or she smiles, how long he or she stays, how ex -
cited and enthusiastic he or she seems to be—but his or her behavior at
this party may be atypical. Perhaps the person has a toothache or doesnot get along with the host.
Behaviorally oriented psychologists would prefer the third strategy ,
behavioral observation, since it seems to be the most objective and sci -
entific. But, as we have pointed out, the contributions of dispositions to
observable behavior are often overshadowed by the press of circum -
stances, and studies have shown that behavior has to be observed over
many occasions before reliable inferences can be made about traits (Ep -
stein, 1979; Fleeson, 2001). In principle, repeated observation is per -38 PERSONALITY IN ADULTHOOD