How Personality Changes Over Time: What Research Tells Us
The Myth of Fixed Personality
For decades, the prevailing belief was that personality solidifies around age 30 and remains essentially unchanged for the rest of life. William James famously wrote that character is "set like plaster" by that age. Modern research has thoroughly overturned this idea.
Longitudinal studies tracking thousands of individuals over decades reveal that personality traits continue to shift well into middle age and beyond. The change is typically gradual -- not dramatic reinventions, but meaningful shifts that accumulate over years.
How Each Big Five Trait Changes With Age
Conscientiousness: The Maturity Principle
Conscientiousness shows the most consistent age-related increase. People generally become more organized, responsible, and self-disciplined as they move from adolescence into middle adulthood. This pattern is so reliable that researchers call it the "maturity principle."
A landmark meta-analysis by Roberts, Walton, and Viechtbauer (2006) found that Conscientiousness increases most sharply between ages 20 and 40, then continues to rise at a slower rate. This likely reflects the demands of adult roles -- careers, parenting, and financial obligations require greater self-regulation.
Agreeableness: Growing Warmer
Agreeableness also tends to increase with age, though the trajectory is more gradual. People become more trusting, cooperative, and empathetic over time. The largest gains appear in middle to late adulthood, suggesting that accumulated social experience fosters greater compassion and patience.
Neuroticism: Emotional Stabilization
Neuroticism generally decreases with age, particularly in women. Emotional reactivity, anxiety, and mood volatility tend to decline from young adulthood onward. By middle age, most people report greater emotional stability and resilience than they experienced in their twenties.
However, this decline is not universal. Some research suggests Neuroticism may increase slightly in very old age as health concerns and social losses mount.
Openness: A Gradual Decline
Openness to Experience tends to peak in late adolescence or early adulthood and then slowly decline. People become somewhat less interested in novelty and abstract ideas as they age, favoring familiar routines and practical thinking. The decline is modest, though -- highly open individuals in their youth typically remain above average in old age.
Extraversion: A Complex Pattern
Extraversion shows a nuanced pattern. Social vitality (warmth and gregariousness) tends to remain stable or increase slightly, while social dominance (assertiveness and activity level) often increases from young adulthood to midlife. Excitement-seeking, however, declines notably with age.
What Drives Personality Change?
Life Events
Major life transitions -- marriage, parenthood, career changes, retirement, bereavement -- can catalyze personality shifts. Research by Specht, Egloff, and Schmukle (2011) found that entering a first romantic relationship was associated with decreased Neuroticism, while divorce was linked to increased Openness.
Social Roles
Adopting new social roles forces behavioral adaptation, which over time can reshape underlying traits. Becoming a manager at work may increase Assertiveness; becoming a caregiver may boost Agreeableness.
Deliberate Effort
Perhaps the most encouraging finding is that intentional effort can shift personality traits. A 2021 study published in the Journal of Personality and Social Psychology found that people who actively worked on changing specific traits -- through therapy, coaching, or self-directed practice -- showed measurable changes over 16 weeks. The effect was especially strong for reducing Neuroticism.
Cultural and Historical Forces
Generational shifts also play a role. Cross-temporal meta-analyses suggest that average Neuroticism scores have been rising across recent decades in Western countries, possibly reflecting increased societal uncertainty and information overload.
Personality Change Is Normal, Not a Crisis
It is important to recognize that personality change does not mean you are "losing yourself." These shifts are typically adaptive -- they help you navigate the evolving demands of life. The person you are at 45 is not a betrayal of who you were at 25; it is a matured version shaped by experience.
Measure Your Personality Today
Understanding where you stand right now on the Big Five dimensions gives you a baseline for tracking your own development. Take our free personality test to get your detailed profile across all five traits and 30 facets, along with an AI-generated deep report.