Verified by 
Personality Change
A personality features a collection of traits that make an individual distinct—traits such as extroversion, openness to new experiences, narcissism, or agreeableness, which some people exhibit more strongly than others. But just because a term like "disagreeable" describes someone well doesn't mean the person necessarily wants to be that way. Procrastinators may wish to become more conscientious; those inclined to gloominess may hope to be more optimistic; the shy may long to be the life of the party. Many people want to change some feature of their personality.
Personality trait measures tend to be fairly stable during adulthood, psychologists have found. Yet research does indicate that there is room for personal evolution, especially over long periods of time as an individual matures. And whether one receives a personality makeover or not, with a little sweat and some luck, it is possible to break out of old behavioral patterns and act more like the person one wants to be.
As consistent as a personality can remain from day to day, research indicates that the adult personality is more malleable than once believed. In studies, individuals do appear to change with age, on average—showing signs of maturation that are measurable through personality questionnaires. Deliberately trying to change one's personality is a different matter, but research has explored ways of doing that, too.
Probably. Extroversion, conscientiousness, agreeableness, and emotional stability are all traits that one may be able to deliberately increase, research suggests, though it’s not yet known how permanent such changes are. They also seem to require active engagement in efforts to change—merely wanting to is likely not enough.
Yes, for many people, it does. Research suggests that people tend to become, for example, calmer and more socially sensitive, and less narcissistic, on average. The idea that agreeableness, conscientiousness, and emotional stability tend to increase with age has been called the “maturity principle.” At the same time, people show marked consistency in terms of how their personalities compare to those of their peers, so someone who is more narcissistic than most may remain so over the years.
While they may not become a “different person,” over the course of a lifetime, a person can show notable increases or decreases in levels of certain personality traits.
Many factors may lead to changes in personality. Genetics influences the development of a person’s traits as they grow up, and personality researchers have argued that important life changes (such as getting married) and new social roles (such as a job) can alter personality traits as well. Research indicates that therapy can produce change, especially on the trait of neuroticism.
Mental health is linked to multiple aspects of personality. The Big Five trait of neuroticism, in particular, has been associated with a variety of mental health conditions, including mood and anxiety disorders, substance use disorders, and certain personality disorders (including borderline personality disorder). Research also suggests that people with some kinds of mental illness, including depression, tend to be relatively low in conscientiousness and extraversion.
Although research is limited, it suggests that brain injury may influence personality. There is evidence, for example, that people who experience a serious head injury or stroke may show decreases in conscientiousness and extroversion.
Interventions designed to get people to behave differently—such as by introducing oneself to new people, showing up early to an event, or other challenges—have, at least in experiments, seemed to move the needle on measures of personality traits. But such efforts may need to be consistent and sustained for (at least) a matter of weeks. Psychotherapy also seems to have the power to create positive personality change.
Engaging in regular social "challenges" might help. Students who wanted to become more extroverted and completed two or more psychologist-devised challenges a week tended to show increases in their questionnaire scores on extroversion over the course of a semester. The exercises ranged from simple steps like saying hello to a cashier or waving to someone who lived nearby, to more involved ones such as going to a Meet Up event or organizing a social outing.
One of the clearest paths to changing a “negative personality” is treatment by a mental health professional, especially psychotherapy (including types such as cognitive behavioral therapy). The strongest reported effects are on the trait of neuroticism, which is sometimes called negative emotionality.
Students who took on two or more conscientious-related challenges a week showed some gains in their scores on the trait over the course of a semester. These included tasks such as “Begin preparing for an event 10 minutes earlier than usual," "Set out your clothes the night before," and "Clean up the dishes as soon as you're done with them."
There are a variety of personality tests, and some are available to the general public. Responding to a questionnaire that assesses the Big Five traits (such as the Big Five Inventory) at different points in time—or having someone else respond to questions about you on your behalf—may help you get a clearer sense of the extent to which your personality has changed. Such tests provide scores for each trait on a continuous scale.
Personality is not set in stone. While research finds some long-term consistency in measures of different personality traits, it also suggests that change is possible even in old age.
