Personality science · 3 min read
Can Personality Change? What Science Actually Says
Personality is stable but not fixed. How traits change across life, what drives the change, and whether you can change yours on purpose.
By the Cognosc team ·
“That’s just who I am” assumes personality is fixed. The research says it’s more interesting than that: personality is fairly stable, it changes in predictable ways across life, and you can nudge it on purpose.
Try it
How personality shifts with age
Slide through adulthood and watch the average person’s traits move.
At 40, the average person is 10 points more conscientious, 6 points more agreeable and 8 points less neurotic than at 18. That’s the average; individuals vary a lot around it, in both directions.
Two kinds of stability
When researchers ask whether personality changes, they mean two different things.
Do you keep your place relative to other people? If you’re more extraverted than most of your friends at 25, you’ll probably still be at 50. This kind of stability is fairly high, and it increases with age: personality becomes more settled through adulthood, levelling off later in life.
Does everyone shift together? Here the answer is yes, and in a consistent direction. On average, as people move through adulthood:
- Conscientiousness goes up. People become more organised and dependable.
- Agreeableness goes up. People become warmer and more cooperative.
- Neuroticism goes down. People become calmer and more emotionally stable.
Researchers call this the maturity principle. Most of the change happens between late adolescence and middle age, but it continues after that.
What drives the change
Some of it seems to be built in, since the same pattern shows up across many cultures. But life plays a big part too, particularly the roles people take on.
- Work. Starting a first serious job is linked to increases in conscientiousness. Roles demand reliability, and doing it every day seems to make it part of you.
- Relationships. Entering a committed relationship is linked to decreases in neuroticism.
- Hard times. Some life events push traits the other way, at least for a while.
One way to think about it: roles ask you to behave in certain ways, and behaviour, repeated long enough, becomes personality.
Can you change on purpose?
This is a younger area of research, but the early results are encouraging.
In studies by Nathan Hudson and Chris Fraley, people who wanted to change a trait, such as becoming more extraverted, and who set specific, concrete goals to act that way (“start a conversation with a colleague this week”) showed modest changes in the direction they wanted over a few months. Vague wishes (“be more outgoing”) did much less.
Therapy changes personality too. A large 2017 review of studies found that people who went through therapy showed noticeable decreases in neuroticism, often within a few months, and the changes tended to last. That’s one of the clearest signs that traits can move.
What changes, and what doesn’t
What tends to shift: how you act, what you’ve practised, how you handle emotions, and over time the traits themselves, a little.
What tends to stay: your basic temperament, the direction you lean. A deep introvert is unlikely to become the life of every party. They can become someone comfortable with parties, which is often what they actually wanted.
Sometimes it isn’t personality at all
What looks like a personality change can be something else.
- A change of circumstances. Someone “disorganised” in a chaotic job may be perfectly organised in a calm one.
- Mood or health. Depression can look like low extraversion and high neuroticism, and lift when it’s treated.
- Skills. Someone who learns to present hasn’t necessarily become more extraverted; they’ve become skilled at something extraverts find easier.
Practical guidelines
- Pick one trait, and one concrete behaviour. Not “be more conscientious” but “plan tomorrow before I finish today”.
- Repeat it until it’s boring. Change comes from behaviour repeated in ordinary life.
- Change the environment, not just yourself. Structure, people and routines can do a lot of the work.
- Work with your nature where you can. A reserved person can build a career on deep, focused work rather than fighting to become loud.
- Get help for the heavy stuff. If worry or low mood is running your life, therapy is one of the most reliable ways personality changes.
See where you are now
Take the free Big Five test and note your scores. It’s a useful baseline to come back to in a year. Attachment patterns change too; the attachment style test shows where yours are today.