In Brief
One of the most frequent questions about the Big Five is also one of the most important: can my personality change? The short answer is yes — but not in the way people generally imagine. Traits change predictably with age, they respond to major life events, and they can be intentionally influenced. This guide explores what research says about the temporal dynamics of personality.
The Maturity Principle
The maturity principle is one of the most robust findings in personality psychology. Formulated by Brent Roberts and colleagues, it describes a universal pattern of trait evolution that accompanies the transition to adulthood and aging.
What generally increases with age:
- Agreeableness — People become on average more cooperative, more empathetic, and less conflict-prone with age. This is not resignation: it is an expansion of the capacity to understand others.
- Conscientiousness — Organization, reliability, and self-discipline increase progressively from adolescence through the fifties. Data shows Conscientiousness continues to increase until around age 65-70 before declining slightly.
- Emotional stability (decrease in Neuroticism) — People manage their emotions better on average at 50 than at 20. Intense emotional reactions to everyday stressors decrease.
What generally decreases with age:
- Neuroticism — Not only the overall level, but also daily emotional variability tends to decrease.
- Openness (slightly, with advancing age) — Openness to new experiences shows a slight decrease after age 60-70 in most longitudinal studies, though the effect is modest and variable.
What remains relatively stable:
- Extraversion — The Extraversion/Introversion dimension is one of the most stable over time. Changes exist but are moderate.
Life Events That Shift Traits
Certain life events produce measurable and lasting trait changes.
Parenthood — Becoming a parent is associated with increased Agreeableness and Conscientiousness in the first years. Zest (Extraversion) may temporarily decrease during the infant period. Effects are generally short to medium term (2-5 years) before partial return to baseline.
Career change — Major professional transitions are associated with Openness changes. Leaving a highly structured environment for more creative work, or vice versa, tends to shift the profile on this axis.
Trauma — Major traumas (bereavement, serious accident, violence) can produce a significant and lasting increase in Neuroticism. The increase is stronger when the trauma is untreated. This underlines the importance of post-traumatic therapeutic support.
Long-term romantic relationships — Longitudinal studies show that stable and satisfying relationships are associated with increased Agreeableness and decreased Neuroticism over the years. The effect is bidirectional: people with low Neuroticism tend to build more stable relationships.
Retirement — Depending on the conditions under which it occurs, retirement can produce opposite effects. Retirement experienced as a loss of meaning is associated with increased Neuroticism. An active, chosen retirement is associated with increased Openness and stable or slightly decreased Neuroticism.
Can Therapy Change Traits?
The question is controversial — and the answer is now clearly yes, under certain conditions.
Meta-analyses on the effects of cognitive-behavioral therapy (CBT) on personality traits show:
- A reduction in Neuroticism that can reach a full standard deviation (SD) after 12 to 24 sessions. This is a considerable effect — equivalent to moving from the 84th percentile to the median.
- A modest but measurable increase in Conscientiousness and Agreeableness.
- Effects on Extraversion and Openness are less consistent.
What this means practically: a person with initially high Neuroticism who follows CBT over several months may end up with a profile that functionally resembles that of a naturally less neurotic person — not because their "real" emotions have disappeared, but because their habitual emotional responses have changed.
Mindfulness (MBSR, mindfulness-based cognitive therapy) produces similar effects on Neuroticism, with an additional increase in Openness in some studies.
The Plasticity vs. Stability Debate
Personality psychology is traversed by a fundamental debate: are the Big Five relatively fixed traits (stability) or modifiable ones (plasticity)?
Arguments for stability:
- Twin studies show heritability of the Big Five between 40% and 60% depending on the trait.
- Relative ranks between individuals (who is more extraverted than whom) remain remarkably stable over 40 years.
- Traits measured in adolescence significantly predict traits at age 60.
Arguments for plasticity:
- Absolute levels change significantly (not just relative ranks).
- Different cultural environments produce different average profiles.
- Therapeutic and intentional interventions produce measurable changes.
Current synthesis: the Big Five are moderately stable in relative ranks but plastic in absolute levels. You will probably remain more introverted than most people around you for your entire life — but your absolute level of introversion can change significantly.
Intentional Personality Change
Can you decide to change a trait and succeed? Research by Hudson and Fraley (2015) is pioneering on this topic.
Their protocol: participants expressed a desire to change a specific trait (increase Extraversion, decrease Neuroticism, etc.) and followed a program of targeted behavioral interventions for 15 weeks.
Results: participants who had stated wanting to change a trait actually produced measurable changes in the desired direction, compared to control groups. The most significant changes concerned Extraversion and Agreeableness. Neuroticism was more resistant to intentional change alone.
Practical implications:
- Explicit desire to change matters — it activates different behaviors.
- Behaviors repeated in the desired direction produce progressive changes.
- Intentional changes are facilitated (but not replaced) by therapeutic support.
Critical Periods for Change
Research identifies two windows of maximum plasticity:
Adolescence (ages 15-25) — Personality is at its most flexible during this period. Educational, social, and family environments have a disproportionate impact. Traumas at this age also have more lasting effects.
Early adulthood (ages 20-30) — This period sees the most significant changes within the maturity principle framework. It is also the window where first long professional and relational experiences produce their strongest effects.
After age 30, changes continue but at a slower pace. This is not a "closing" — it is progressive consolidation.
Personality and Aging
Longitudinal studies on aging show a phenomenon that is often counter-intuitive: older people generally report higher subjective well-being than young adults — despite real physical, social, and cognitive losses.
This is partly explained by trait changes: decreased Neuroticism reduces negative emotional reactions to everyday stressors. Increased Agreeableness improves the quality of remaining relationships. Increased Conscientiousness improves health habits.
However, after age 80, some traits show a slight trend reversal, often correlated with cognitive decline. Conscientiousness may decrease in the final years of life.
Neurodivergent Section
Neurodivergent profiles often experience trait evolution differently from normative curves.
HPI (High Intellectual Potential) — People with HPI frequently show Openness to experience that is already very high and tends to remain high or even increase with age. The maturity process for Conscientiousness can be slower — not from lack of capacity, but from resistance to structures perceived as arbitrary. Progressively individualizing these structures (creating one's own organization) generally accelerates this development.
ADHD — The development of Conscientiousness in people with ADHD typically follows a 3 to 5 year delay compared to developmental norms — without being absent. Longitudinal follow-up studies show that Conscientiousness can reach normal adult levels at ages 30-35 in people diagnosed with ADHD, particularly with therapeutic support.
HSP (Highly Sensitive Person) — Highly sensitive people often have initially higher Neuroticism — but they can also benefit proportionally more from therapeutic interventions on this axis. Mindfulness and emotion regulation-focused therapies (DBT, sensorimotor therapy) produce particularly marked Neuroticism reductions in this population.
What This Changes Practically
The most useful question is not "can my personality change?" but "how can I work with my current personality while it naturally evolves?"
The Big Five describe tendencies, not destinies. Knowing your Neuroticism is high does not condemn you to suffering — it informs you about the contexts, practices, and supports that will allow you to reduce that suffering more effectively. Knowing your Conscientiousness naturally increases with age allows you to stop treating every current planning difficulty as a permanent flaw.
Personality is not a cage. It is a map — with easier zones and zones that require more effort. The map changes over time, and you can modestly but genuinely influence the direction of that change.