adults on the NEO Personality Inventory (Costa & McCrae, 1985,
1989a), our measure of the five factors of personality , we find that stu -
dents are somewhat higher than adults in Neuroticism, Extraversion,
and Openness, and lower in Agreeableness and Conscientiousness.These differences suggest (although, as our discussion of cross-sectionalresearch in Chapter 4 will explain, they do not prove ) that college stu -
dents mature and mellow a bit, becoming a little less emotional and
flexible, but kinder and more responsible.
If we define adulthood as the period from age 18 on, studies like
this make it clear that there is indeed adult development in several as -
pects of personality . We have adopted a different definition of adult -
hood. The data suggest to us that personality change is the exception
rather than the rule after age 30; somewhere in the decade between 20and 30, individuals attain a configuration of traits that will characterizethem for years to come. From the perspective of the trait psychologist,adulthood begins at that point.
OTHER VIEWS: THEORIES OF CHANGE
A brief introduction to theories of change is an essential starting pointfor this book; much more will be said about the theories of DanielLevinson and Roger Gould in Chapter 9. Readers may want to consultthe original sources for more extended (and perhaps more objective) ac-counts of these theories.
Among major personality theorists, only two made significant con -
tributions to lifespan theory: Jung and Erikson. The former left rela -
tively unstructured ideas but was very influential in turning attention to
the later years. Erikson, on the other hand, produced an elaborate andfinely articulated theory that has become the basis of considerable em -
pirical work (e.g., McAdams & de St. Aubin, 1998; Tesch & Cameron,
1987; Whitbourne, 1986a, 1986b). His theory of eight stages of life isprobably the most important classic theory of adult personality devel -
opment.
Jung, it will be recalled, objected philosophically to Freud’s empha -
sis on sexuality . Jung proposed that sexual development was central to
personality only in the young, in whom the function of procreation wasvested. Past the age of 40 there must, he felt, be other sources of growth,other areas of concern to the individual. These were more likely to beFacts and Theories of Adult Development 11