It should be clear by this point that personality is characterized by stability over the life span, and also by significant change. As we have seen, many processes have been proposed to explain both of these facts. But these processes interact and sometimes even seem to contradict each other, and their sheer number can be overwhelming. The psychologists Brent Roberts, Dustin Wood, and Avshalom Caspi made a significant contribution, therefore, when they proposed a list of seven principles for personality development (Roberts, Wood, & Caspi, 2008).
The principles are not exactly empirical facts, nor are they theoretical statements. They are general claims about the bases of personality development and change, and each of them can serve as a guide to future research (see Table 7.2). The first is the cumulative continuity principle, which was mentioned earlier in this chapter; it is the proposal that personality becomes more consistent as the individual gets older. The second, also mentioned earlier, is the maturity principle, which proposes that people become better equipped to deal with the demands of life as they acquire experience and skills.
Table 7.2PRINCIPLES OF PERSONALITY DEVELOPMENT
Cumulative continuity principle
Personality traits increase in rank-order consistency as people get older.
Maturity principle
People become better equipped to deal with the demands of life as they acquire experience and skills.
Plasticity principle
Personality can change at any time (but such change may not be easy).
Role continuity principle
Taking on roles or images such as being a “jock” or a “brain” can lead personality to be consistent over time.
Identity development principle
People seek to develop a stable sense of who they are, and then strive to act consistently with this self-view.
Social investment principle
Changing social roles at different stages of life, such as becoming a spouse, parent, or boss, can cause personality to change.
Corresponsive principle
Person-environment transactions can cause personality traits to remain consistent or even magnify over time.
Source: Adapted from Roberts, Wood, & Caspi (2008), p. 376.
The other principles have not been mentioned by name yet in this chapter, but we have seen examples of how they operate. The plasticity principle asserts that personality can change at any time during the life course, though such change may not be easy. The role continuity principle presents the idea that people choose “roles” to play that may stay the same over their lives, such as the person who becomes a “jock” or “brain” in high school and continues to enact that role in college and adult life. The identity development principle states that people construct a sense of “who am I” as they grow up, and that this self-view becomes an important foundation of behavioral stability as people try to be consistent with their sense of self. This principle is closely related to the process of identity formation described by Dan McAdams and summarized earlier in this chapter. The social investment principle describes how people become connected to social structures and institutions, and how this connection affects their psychological development. In particular, people are expected to—and generally do—connect differently to the social world as they progress from child to parent to grandparent, and from student to employee to boss. This principle can be seen to underlay Ravenna Helson’s notion of the social clock, described earlier in the chapter. Finally, the corresponsive principle relates how life experience tends to magnify the personality traits that already exist, and establish them ever more firmly over time. The person-environment transactions discussed earlier, and listed in Table 7.1, illustrate how this process works.
You may have heard the expression that “as you get older, you just become more like the way you were all along.” I don’t know if this cliché is literally true, but notice how it does embody notions of both continuity and change over the life course. Perhaps it deserves inclusion as an eighth principle of personality development. What do you think?