• What is the five-factor model of dispositional traits?

• What evidence is there for long-term stability in dispositional traits?

• What criticisms have been leveled at the five-factor model?

• What can we conclude from theory and research on dispositional traits?


bby was attending her high school reunion. She hadn’t seen her friend Michelle in 20 years. Abby remembered that in high school Michelle was always surrounded by a group of people. She always walked up to people and initiated conversations, was at ease with strangers, was pleasant, and was often described as the “life of the party.” Abby wondered if Michelle would be the same outgoing person she was in high school.

Most of us will eventually attend a high school reunion. It is amusing, so it is said, to see how our classmates have changed over the years. In addition to noticing gray or missing hair and a few wrinkles, we should pay attention to personality characteris­tics. The questions that arose for Abby are similar to the ones we generate ourselves. For example, will Katy be the same outgoing person she was as captain of the cheerleaders? Will Ted still be as concerned about social issues at 48 as he was at 18? To learn as much about our friends as possible, we could make careful observations of our classmates’ personalities over the course of several reunions. Then, at the gathering marking 60 years since graduation, we could examine the trends we observed. Did our classmates’ personalities change substantially? Or did they remain essentially the same as they were 60 years earlier?

How we think these questions will be answered provides clues to our personal biases concerning personality stability or change across adulthood. As we will see, biases about continuity and discontinuity are more obvious in personality research than in any other area of adult development.

In addition to considering the old debate of whether Michelle’s personality characteristics will have remained stable or have changed, Abby’s description


Would your classmates’ personalities remain the same at your college reunion?

of Michelle suggests that Michelle is an outgoing, or extroverted, person. How did Abby arrive at this judgment? She probably combined several aspects of Michelle’s behavior into a concept that describes her rather concisely. What we have done is to use the notion of a personality trait. Extending this same reasoning to many areas of behavior is the basis for trait theories of personality. More formally, people’s characteristic behaviors can be understood through attributes that reflect underlying dispositional traits, which are relatively enduring aspects of personality. We use the basic tenets of trait theory when we describe ourselves and others with such terms as calm, aggressive, independent, friendly, and so on.

Three assumptions are made about traits (Costa & McCrae, 1998). First, traits are based on compari­sons of individuals, because there are no absolute quantitative standards for concepts such as friendli­ness. Second, the qualities or behaviors making up a particular trait must be distinctive enough to avoid confusion. Imagine the chaos if friendliness and aggressiveness had many behaviors in common yet had some that were vastly different! Finally, the traits attributed to a specific person are assumed to be sta­ble characteristics. We normally assume that people who are friendly in several situations are going to be friendly the next time we see them. These three assumptions are all captured in the definition of a trait: A trait is any distinguishable, relatively endur­ing way in which one individual differs from others (Guilford, 1959, p. 6). Based on this definition, trait theories assume that little change in personality will

occur across adulthood. The primary interest here is when trait stability peaks and when traits stop changing.

Most trait theories have several guiding princi­ples in common. An important one for our present discussion concerns the structure of traits. Structure concerns the way in which traits are organized within the individual. This organization is usually inferred from the pattern of related and unrelated traits and is generally expressed in terms of dimen­sions. Personality structures can be examined over time to see whether they change with age.