Do People Change Their Personality? What the Research Actually Says

Ask whether personality changes and you get two confident answers, both delivered as if the matter were settled. One camp says people never really change. The other says they have watched someone change completely. Both are describing something real, and both are answering a different question than the one personality research is set up to answer.

Do people change their personality?

Yes, measurably, but slowly, in patterned directions, and much less over any given year or two than people expect. Six decades of longitudinal work converge on that answer. Traits shift across adulthood in predictable average directions, individuals hold their relative position against their peers fairly well, and the distance traveled over a lifetime is real but accumulates in small increments rather than one transformative stretch.

Popular coverage is contradictory because "does personality change" collapses three distinct research questions into one sentence. Separating them resolves most of the apparent disagreement.

What did psychologists used to believe about personality change?

William James wrote in 1890 that character is "set like plaster" by around age thirty. A century later, Paul Costa and Robert McCrae borrowed the phrase and gave it data. Their position through the 1980s and early 1990s was that trait levels are essentially fixed after about thirty, that change past that point was small enough to treat as noise, and that adult personality was better described as maintenance than development.

The field moved past that position, and Costa and McCrae themselves revised toward a more graded account in later work. Two things forced the revision: samples large enough to detect effects smaller studies were underpowered to see, and meta-analytic methods that let researchers pool decades of separate longitudinal studies. Sanjay Srivastava, Oliver John, Samuel Gosling, and Jeff Potter's 2003 study of well over a hundred thousand adults, framed directly against the plaster metaphor, found conscientiousness and agreeableness still rising well past thirty.

What are the three kinds of personality change, and why do they get confused?

This is the distinction most popular coverage collapses.

• Mean-level change asks whether the average person scores higher or lower on a trait at fifty than at twenty. It is a statement about a population, not about anyone in it.
• Rank-order stability asks whether people hold their position relative to each other. If the most conscientious twenty-five-year-olds are still the most conscientious fifty-year-olds, rank-order stability is high even if everyone's absolute score rose.
• Individual-level change asks what happened to one specific person. This is what people usually mean, and the other two measures cannot answer it.

Those three can point in different directions at once. A cohort can show a large mean-level rise in conscientiousness while rank-order stability stays high, because nearly everyone drifted upward together, and one person can move sharply against the trend without disturbing either number. Brent Roberts and Daniel Mroczek made this point in their 2008 review, and Mroczek's work with Avron Spiro on the Normative Aging Study showed it directly: some men's neuroticism rose over the same years the group average was falling.

How much does personality change with age?

Brent Roberts, Kate Walton, and Wolfgang Viechtbauer's 2006 meta-analysis in Psychological Bulletin, pooling roughly ninety longitudinal studies, produced the clearest picture available. The pattern they found is now usually called the maturity principle: on average, across adulthood, conscientiousness and agreeableness rise, emotional stability rises (which is to say neuroticism declines), and the social dominance component of extraversion rises, with most of the movement concentrated in the twenties and thirties rather than spread evenly across the lifespan. Openness rises through adolescence and young adulthood and tends to decline in later life.

The magnitudes deserve care. Cumulated from the twenties into middle age, some of these traits move on the order of a standard deviation, which is a large amount. Sliced into any single year, the same change is nearly undetectable. Both are true, and reporting one without the other is how this research gets distorted.

Rank-order stability follows its own curve. Roberts and Robert DelVecchio's meta-analysis found test-retest correlations climbing with age, from roughly the .3 range in childhood to near the .5 range around thirty and up toward the .7 range after fifty. That rise is the important finding, and so is the ceiling it never reaches: a correlation in the .7 range still leaves substantial room for individuals to move. Stability increases with age. It does not become fixity. Rodica Damian, Marion Spengler, and colleagues, following participants for roughly fifty years, found that same combination of stability and real average change.

Can life experiences change your personality?

The evidence here is suggestive and should be read with care about causal language, because most of it is observational: people select into their circumstances rather than being assigned to them.

The best-developed account is what Roberts and colleagues call social investment: committing to adult roles, particularly stable work and stable partnership, is associated with trait change in the maturity direction. Roberts, Avshalom Caspi, and Terrie Moffitt's analysis of the Dunedin cohort found that young adults whose work experiences went well showed corresponding increases in conscientiousness and emotional stability. Franz Neyer and Jens Asendorpf found a similar association around entry into a first serious partnership. Investment in the role, not occupancy of it, is what the data track.

Intervention research adds the closest thing to an experiment. Roberts and colleagues' 2017 meta-analysis of more than two hundred intervention studies, a mix of randomized trials and pre-post designs, found measurable trait change in patients in therapy, with the largest effects on emotional stability, on the order of roughly half a standard deviation over an average of about six months. Nathan Hudson and Chris Fraley's work on volitional change points the same way at lower intensity: people who set specific trait goals and act on them move somewhat, though intention alone does not do it.

Why does VITALS measure personality once?

Everything above is empirical. What follows is a design judgment, and it should be labeled as one rather than presented as a finding.

VITALS measures its six dimensions once and treats them as a stable foundation. That is a decision about the timescale the instrument is built for, not a claim that personality is immutable. An instrument meant to inform decisions about work, fit, and direction operates on a timescale of months and years, and on that timescale the research above says the trait layer is the slow-moving part of the picture. Temperament illustrates why:

Temperament: Your emotional patterns, energy, and stress responses — how you experience and regulate emotion, what energizes or drains you, and how you show up under pressure.

Temperament has the deepest early-life roots of the six, which is why temperament and personality are not the same construct. It is also the clearest case for anchoring: a trait that moved constantly would not be worth building a profile on, and a trait this stable is.

This is also the reason a living personality profile separates two layers. The six-dimension foundation is measured once and stays fixed, while a context layer built from goals, feedback, decisions, and life stage is layered on top and updates over time. The research on slow trait change and the research on fast context change point at different measurement needs. One layer answers what tends to be true about a person. The other answers what is true about the situation in front of them.

What are people actually asking when they ask this question?

Usually one of two things. "Can I change" is a question about one person with a specific goal, and the research answers it only in aggregate: change in the maturity direction is common, effortful change is possible, and the realistic scale is modest and slow rather than total. "Did that person really change" is about someone else's behavior, and the research helps even less there, because a single behavior is not a trait score and one observation cannot separate a changed disposition from a changed situation.

What the research does supply is a better frame for both. Knowing where a person sits on a continuous dimension, rather than which category they were sorted into, makes the question answerable in degrees instead of absolutes. That is part of the practical difference between personality types and personality dimensions, and it is what turns a result into actionable self-awareness rather than a verdict.

Frequently Asked Questions

At what age does personality stop changing?

It does not stop. The rate slows. Rank-order stability rises steadily with age, reaching its highest levels after fifty, and mean-level change is concentrated most heavily in the twenties and thirties. The older claim that traits are essentially fixed by thirty did not hold up once larger samples and meta-analytic pooling became available.

Can you change your personality on purpose?

To a degree, and the effect is larger when specific behavior is involved rather than intention alone. Hudson and Fraley found that people who set concrete trait goals and acted on them moved measurably, while wanting to change produced little on its own. The clinical literature shows the largest effects: roughly half a standard deviation in emotional stability across about six months of therapy.

What is the maturity principle in personality psychology?

It is the finding, established most clearly by Roberts, Walton, and Viechtbauer's 2006 meta-analysis, that adults on average become more conscientious, more agreeable, and more emotionally stable as they age, with most of the movement between the early twenties and middle age. It is a population average, not a guarantee about any individual, and a meaningful number of people move against it.

Does a big life event change your personality?

Sometimes, and less reliably than the popular version of this idea suggests. The strongest associations involve sustained role investment, particularly stable work and stable partnership, rather than discrete events. This evidence is largely observational, so it establishes association rather than causation: people also select into the roles associated with the change.

Does the VITALS assessment track how your personality changes over time?

No. VITALS measures the six dimensions once and treats them as the stable foundation of the profile. What updates over time is the context layer built on top of it: goals, feedback, decisions, and life stage. The design assumption is that traits move on a timescale of years and context moves on a timescale of weeks, so the two are measured differently on purpose.

Where you sit on a trait doesn't move much year to year, which is exactly why it's worth measuring once and measuring well. The VITALS assessment scores six dimensions on continuous scales, drawing on Jungian typology, Cattell's 16 Personality Factors, and Holland's interest themes. Twenty minutes, free to start.