An important aspect of any theory regarding human personality is that theory’s views on how much people can change over time. Do people stay the same all their lives? If so, what accounts for that change, and how much can a person change? Such views give insight on how malleable the theory is. Two personality theorists, Hans Eysenck and Carl Rogers, both have ideas about personality theory offer interesting insights on how much people can change.

According to Rogers, the individual is responsible for his or her own personality. In fact, there is no certain kind of person. Rather, Rogers argues that there are simply ways of living. One such way of living that Rogers claims is most important is self-actualization, the tendency to grow in ways that lead to self-enhancement. By nature, people work towards this tendency. When it comes to change, Rogers believes that there is no limit. Self-actualization is not a specific end-goal, rather, it is something to strive for. The therapy that Rogers developed—client-centered therapy—supports his view. Instead of presenting clients with assumptions and judgments about their behavior, the therapist empathizes with them and helps them come to their own conclusions about their behavior. This can lead to change in any direction.

Eysenck believes a person’s personality depended on specific traits. Two traits he considers most important are extraversion and neuroticism. Just as Rogers believes people have an innate tendency to act towards self-actualization, Eysenck argues that extraversion and neuroticism are innate, rooted in the brain, the product of processes in the nervous system. Change—or as Eysenck puts it, conditioning—can result from emotional arousal, but how much a person changes depends on how extraverted they are. Introverts are easier to condition because they are easily stimulated. Extraverts, on the other hand, are harder to condition because they require much more stimulation in order to be aroused. Once a person is emotionally aroused, they can “become more of what they are.” A therapist with Eysenck’s view of personality would be more likely to help a client change by making them aware of the differences between introversion and extraversion and may even vary their approach depending on whether or not the client is introverted or extraverted.
In sum, Rogers’s view suggests that people are more changeable, because he does not assume that certain traits are inherent in a person. Rather, each person has the potential to grow indefinitely. If you want to be a certain way, you ultimately can. Eysenck’s view suggests that people’s personalities are determined by traits, which depend on very the make-up of their nervous systems. Because it assumes that these traits are essentially built-in, Eysenck’s theory suggests that people can only change up to a certain point.