So…How Stable Is Your Personality?

We’ve seen that people can act differently depending on the situation. But a bigger question is: does personality change over the course of your life, or are you basically the same person forever?

Research suggests a “both/and” answer: personality is fairly stable, especially as we get older, but it can also shift in meaningful ways—especially during major life transitions.

Personality Changes With Age

When researchers look at average patterns across large groups of people, they find that personality tends to change in predictable ways across adulthood. A meta-analysis of Big Five studies found that, on average:

• Extraversion (especially social confidence and assertiveness) tends to increase with age
• Agreeableness tends to increase with age
• Conscientiousness tends to increase with age
• Neuroticism tends to decrease with age
• Openness tends to decline somewhat, especially after midlife (Roberts et al., 2006)

maturity principle of adult personality development

This general pattern is called the maturity principle (Caspi, Roberts, & Shiner, 2005). The idea is that traits associated with effective adult functioning—like being responsible, emotionally steady, and cooperative—tend to increase across adulthood on average.

These trends are often considered “maturing” because higher conscientiousness and agreeableness (and lower neuroticism) are linked to outcomes like stronger relationships, better work outcomes, better health, and fewer mental health and behavioral problems.

When does the most change happen?

Roberts et al. (2006) found that young adulthood (roughly ages 18 through the late 20s) is often one of the most active periods for personality change. That may be because it’s a time when many people take on new roles and responsibilities—finishing school, entering the workforce, building long-term relationships, or becoming parents (Donnellan et al., 2007; Rindfuss, 1991).

This supports the idea that personality doesn’t develop in isolation: adult roles and environments may create pressure to become more organized, emotionally regulated, and socially skilled.

Life Events Can Shift Personality—Even if the Effects Are Small

Average trends don’t describe everyone. People vary a lot in how and when they change.

Recent research suggests that life events can produce small but meaningful shifts in personality. A 2024 meta-analysis found that events like graduating, beginning a new job, marriage, and divorce are associated with modest personality changes, with work-related transitions showing more consistent effects than relationship events (Bühler et al., 2024). Another 2024 study using frequent assessments found that some life events can alter a person’s personality trajectory, though the effects are not always large or consistent (Dugan et al., 2024).^[1][2]

Stability Increases With Age

Even though personality can change, it also becomes more consistent as we move from childhood into adulthood.

Roberts and DelVecchio (2000) reviewed over 3,000 test–retest correlations from 152 longitudinal studies and found that personality stability increases with age. Over roughly seven-year intervals, stability estimates ranged from about:

• .30 in young childhood
• up to about .70 in older adulthood

Later work has supported this general pattern (Ferguson, 2010).

This pattern is known as the cumulative continuity principle (Caspi et al., 2005). In simple terms: as people age, their traits often become more stable—partly because they build routines, relationships, and environments that reinforce their typical ways of thinking and behaving.

Still, stability is never perfect at any age. That means personality change can occur throughout life—it just tends to be more common (and more visible) earlier on.

Conclusions

Overall, research suggests that personality traits are relatively enduring and become more stable from childhood to adulthood. However, they are not “set in stone.”

This challenges two extreme views:

• “Personality is set like plaster by age 30.” (often attributed to William James)
• “Personality isn’t stable at all—it’s just the situation.”

Modern research supports a middle ground: personality shows meaningful consistency, but it can also change—especially through repeated experiences, new roles, and major life events.

A helpful way to think about it is a feedback loop:

• personality traits shape the environments people choose and create,
• and those environments often reinforce those traits over time.

Even so, change is possible—because people respond, adapt, and sometimes intentionally work to grow in new directions.

---