Although many different trait theories of personality have been proposed over the years, few have been concerned with or have been based on adults of different ages. A major exception to this is the five – factor model proposed by Costa and McCrae (1994; McCrae, 2002). Their model is strongly grounded in cross-sectional, longitudinal, and sequential research. The five-factor model consists of five independent dimensions of personality: neuroticism, extraversion, openness to experience, agreeableness, and conscientiousness.

The first three dimensions of Costa and McCrae’s model—neuroticism, extraversion, and openness to experience—have been the ones most heavily researched. Each of these dimensions is represented by six facets that reflect the main characteristics associated with it. The remaining two dimensions were added to the original three in the late 1980s to account for more data and to bring the theory closer to other trait theories. In the following sections we will consider each of the five dimensions briefly.

Neuroticism. The six facets of neuroticism are anxiety, hostility, self-consciousness, depression, impulsive­ness, and vulnerability. Anxiety and hostility form underlying traits for two fundamental emotions: fear and anger. Although we all experience these emotions at times, the frequency and intensity with which they are felt vary from one person to another. People who are high in trait anxiety are nervous, high-strung, tense, worried, and pessimistic. Besides being prone to anger, hostile people are irritable and tend to be hard to get along with.

The traits of self-consciousness and depression relate to the emotions shame and sorrow. Being high in self-consciousness is associated with being sensitive to criticism and teasing and to feelings of inferiority. Trait depression involves feelings of sadness, hopelessness, loneliness, guilt, and low self­worth.

The final two facets of neuroticism—impulsive – ness and vulnerability—are most often manifested as behaviors rather than as emotions. Impulsiveness is the tendency to give in to temptation and desires because of a lack of willpower and self-control. Consequently, impulsive people often do things in excess, such as overeating and overspending, and they are more likely to smoke, gamble, and use drugs. Vulnerability involves a lowered ability to deal effectively with stress. Vulnerable people tend to panic in a crisis or emergency and tend to be highly dependent on others for help.

Costa and McCrae (1998) note that, in general, people high in neuroticism tend to be high in each of the traits involved. High neuroticism typically results in violent and negative emotions that interfere with people’s ability to handle problems or to get along with other people. We can see how this cluster of traits would operate. A person gets anxious and embar­rassed in a social situation such as a class reunion, the frustration in dealing with others makes the person hostile, which may lead to excessive drinking at the party, which may result in subsequent depression for making a fool of oneself, and so on.

Extraversion. The six facets of extraversion can be grouped into three interpersonal traits (warmth, gregariousness, and assertiveness) and three tem­peramental traits (activity, excitement seeking, and positive emotions). Warmth, or attachment, is a friendly, compassionate, intimately involved style of interacting with other people. Warmth and gre­gariousness (a desire to be with other people) make up what is sometimes called sociability. Gregarious people thrive on crowds; the more social interaction, the better. Assertive people make natural leaders, take charge easily, make up their own minds, and readily express their thoughts and feelings.

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Temperamentally, extraverts like to keep busy; they are the people who seem to have endless energy, talk fast, and want to be on the go. They prefer to be in stimulating, exciting environments and will often go searching for a challenging situation. This active, exciting lifestyle is evident in the extravert’s positive emotion; these people are walking examples of zest, delight, and fun.

An interesting aspect of extraversion is that this dimension relates well to occupational interests and values. People high in extraversion tend to have people-oriented jobs, such as social work, business administration, and sales. They value humanitarian goals and a person-oriented use of power. People low in extraversion tend to prefer task-oriented jobs, such as architecture or accounting.

Openness to Experience. The six facets of openness to experience represent six different areas. In the area of fantasy, openness means having a vivid imagina­tion and active dream life. In aesthetics, openness is seen in the appreciation of art and beauty, sensitivity to pure experience for its own sake. Openness to action entails a willingness to try something new, whether it be a new kind of cuisine, a new movie, or a new travel destination. People who are open to ideas and values are curious and value knowledge for the sake of knowing. Open people also tend to be open-minded in their values, often admitting that what may be right for one person may not be right for everyone. This outlook is a direct outgrowth of open individuals’ willingness to think of different possibilities and their tendency to empathize with others in different circumstances. Open people also experience their own feelings strongly and see them as a major source of meaning in life.

Not surprisingly, openness to experience is also related to occupational choice. Open people are likely to be found in occupations that place a high value on thinking theoretically or philosophically and less emphasis on economic values. They are typically intelligent and tend to subject themselves to stressful situations. Occupations such as psychologist or minister, for example, appeal to open people.

Agreeableness. The easiest way to understand the agreeableness dimension is to consider the traits that

320 CHAPTER 9 characterize antagonism. Antagonistic people tend to set themselves against others; they are skeptical, mistrustful, callous, unsympathetic, stubborn, and rude; and they have a defective sense of attachment. Antagonism may be manifested in ways other than overt hostility. For example, some antagonistic peo­ple are skillful manipulators or aggressive go-getters with little patience.

Scoring high on agreeableness, the opposite of antagonism, may not always be adaptive either, however. These people may tend to be overly depen­dent and self-effacing, traits that often prove annoy­ing to others.

Conscientiousness. Scoring high on conscientious­ness indicates that one is hardworking, ambitious, energetic, scrupulous, and persevering. Such people have a strong desire to make something of them­selves. People at the opposite end of this scale tend to be negligent, lazy, disorganized, late, aimless, and not persistent.

What Is the Evidence for Trait Stability or Change? Costa and McCrae have investigated whether the traits that make up their model remain stable across adulthood (e. g., Costa & McCrae, 1988, 1997; McCrae & Costa, 1994). In fact, they suggest personality traits stop changing by age 30 and appear to be “set in plaster” (McCrae & Costa, 1994, p. 21). The data from the Costa, McCrae, and colleagues’ studies came from the Baltimore Longitudinal Study of Aging for the 114 men who took the Guilford-Zimmerman Temperament Survey (GZTS) on three occasions, with each of the two follow-up testings about 6 years apart. What Costa and colleagues found was surprising. Even over a 12-year period, the 10 traits measured by the GZTS remained highly stable; the correlations ranged from.68 to.85. In much of personality research we might expect to find this degree of stability over a week or two, but to see it over 12 years is noteworthy.

We would normally be skeptical of such con­sistency over a long period. But similar findings were obtained in other studies. In a longitudinal study of 60-, 80-, and 100-year-olds, Martin and colleagues (2003) found that there were no signifi­cant changes across overall personality patterns.

However, some interesting changes did occur in the very old. There was an increase in suspicious­ness and sensitivity. This could be explained by increased wariness of victimization in older adult­hood. Stability was also observed in past longitudi­nal data conducted over an 8-year span by Siegler, George, and Okun (1979) at Duke University, a 30-year span by Leon, Gillum, Gillum, and Gouze (1979) in Minnesota, and in other longitudinal studies (Schaie & Willis, 1995; Schmitz-Scherzer & Thomae, 1983). Even more amazing was the find­ing that personality ratings by spouses of each other showed no systematic changes over a 6-year period (Costa & McCrae, 1988). Thus, according to this evidence it appears that individuals change very little in self-reported perso nality traits over periods of up to 30 years long and over the age range of 20 to 90 years of age.

However, there is growing evidence that both stability and change can be found in personal­ity trait development across the adult life span (Allemand, Zimprich, & Hendriks, 2008; Caspi, Roberts, & Shiner, 2005; Mathias, Allemand, Zimprich, & Martin, 2008). These findings came about because of recent advances in statistical tech­niques. Researchers find that the way people differ in their personality becomes more pronounced with older age (Allemand et al., 2008). Furthermore, other studies (Donnellan & Lucas, 2008) find that extra­version and openness decrease with age whereas agreeableness increases with age. Middle-aged adults are the most conscientious. Finally, neuroti – cism slightly decreases or is absent with increasing age. Such changes are found in studies that examine larger populations across a larger age range (e. g., 16 to mid-80s) and across greater geographical regions (e. g., United States and Great Britain).

Clearly, lots of things change in people’s lives over 30 years. They marry, divorce, have children, change jobs, face stressful situations, move, and maybe even retire. Social networks and friendships come and go. Society changes, and economic ups and downs have important effects. Personal changes in appearance and health occur. People read books, see dozens of movies, and watch thousands of hours of television. There are other approaches that examine
underlying personality dispositions that also detect change across the adult life span.