Short answer: Yes, more than the old stereotype of a “fixed” adult personality suggests. Long-term studies find that personality traits shift gradually and fairly predictably across adulthood, typically toward greater emotional stability, agreeableness, and conscientiousness. On top of this natural drift, more recent randomized research shows people can meaningfully speed up desired changes in their own personality through deliberate, sustained effort.
The Natural Pattern: The “Maturity Principle”
The dominant finding in personality research is what psychologists call the maturity principle: on average, people tend to become more emotionally stable, more agreeable, and more conscientious as they move through adulthood, traits that broadly overlap with what most cultures consider psychological maturity. A large-scale study following adults over time found that, consistent with this pattern, agreeableness and conscientiousness tend to increase while neuroticism tends to decrease across adulthood, and that people’s relative ranking compared to their peers on these traits also becomes more stable with age, a related pattern called cumulative continuity.
This isn’t a fringe or one-off result. A comprehensive meta-analysis pulling together numerous longitudinal studies confirmed the maturity principle holds well for emotional stability, agreeableness, and conscientiousness specifically, while noting that the trajectories for the other two Big Five traits, openness and extraversion, are less consistent across studies and life stages. The leading explanation for why maturation happens at all is social: as people take on adult roles, like committed relationships, steady work, and parenting, those roles create ongoing pressure and practice toward more responsible, emotionally regulated, cooperative behavior, which gradually reshapes the underlying trait.
It’s Not Guaranteed, and It’s Not the Same for Everyone
The maturity principle describes an average trend, not a universal law. Studies that identify distinct subgroups within larger samples consistently find that some people show much larger personality shifts than others over the same stretch of time, while some show little change or even move in the opposite direction. Research using a large, long-running American survey identified three fairly distinct patterns among adults tracked over 20 years: some people showed pronounced increases in these mature traits, others stayed relatively stable, and a third group actually declined, with the “increasers” tending to be younger than the other two groups. Cultural and demographic context matters too; longitudinal research on Mexican-origin adults found a different overall pattern of trait change than typically reported in predominantly white, middle-class samples, a reminder that much of the foundational personality-change research doesn’t automatically generalize to every population.
The More Surprising Finding: You Can Speed This Up on Purpose
Beyond the slow, largely unconscious drift of natural maturation, a newer and genuinely striking line of research asks a more pointed question: can people deliberately change their own personality just by wanting to and trying? Psychologists Nathan Hudson and Chris Fraley ran a series of randomized, intensive longitudinal studies to find out. In their original study, they found that people who expressed a goal to increase on any of the Big Five personality traits tended to show real, measurable increases in that trait, along with corresponding changes in trait-relevant daily behavior, over the following 16 weeks. People who wanted to become more extraverted, for instance, actually became somewhat more extraverted, not just in self-report but in how they behaved day to day.
Follow-up research has strengthened this finding considerably. A large mega-analysis pooling roughly a dozen separate intensive longitudinal studies confirmed that change goals robustly predicted real trait growth, with the strongest effects for extraversion and emotional stability. Critically, researchers also found that simply having a change goal wasn’t enough on its own; what mattered most was whether people actually followed through with concrete, trait-relevant behaviors, and one randomized intervention that specifically trained participants to form detailed implementation plans, rather than vague intentions, meaningfully boosted their success at achieving the change they wanted.
What This Means in Practice
- Don’t assume your personality at 25 is your personality for life. The maturity principle describes real, gradual shifts across decades of adulthood, not a fixed trait profile set at some early cutoff.
- If you want to change a specific trait, translate the wish into concrete behavior, not just intention. Research consistently shows that follow-through on trait-relevant daily actions, not the goal itself, is what predicts actual change.
- Expect gradual movement, not a dramatic overnight shift. Even in the most successful intervention studies, change unfolded over months of sustained effort, consistent with how slowly natural personality maturation happens too.
- Recognize that pursuing meaningful personal change is linked to greater well-being, not less. Research following people’s change goals over time found that successfully moving toward a desired change was associated with improved psychological well-being, undercutting the worry that wanting to be different is inherently a sign of dissatisfaction or self-rejection.
Personality isn’t the fixed, unchangeable core it’s sometimes made out to be. It shifts on its own gradually across adulthood, largely in the direction of greater maturity, and current research suggests you have more genuine influence over the direction and pace of that shift than the old stereotype ever gave you credit for.
