"People don't change" is one of the most popular beliefs about adult personality. The research says otherwise — but the changes are slower, smaller and more predictable than motivational speakers imply. Here's what longitudinal studies of tens of thousands of people have found.
The maturity principle The cleanest finding in personality psychology: people gradually become more mature between 20 and 40. Specifically: - Conscientiousness rises - Agreeableness rises - Neuroticism (emotional reactivity) declines
This pattern shows up in every culture studied, across dozens of countries. Something about adult life — work, relationships, caring for others — reliably shifts people in this direction. You can accelerate it, slow it, or fight it, but on average most people move this way without trying.
The shift isn't small. A 40-year-old is, on average, about half a standard deviation higher on Conscientiousness than a 20-year-old. That's the difference between scoring 50th percentile and 69th percentile — noticeable.
What happens in midlife Between 40 and 60: - Conscientiousness continues to rise, slowly - Neuroticism continues to decline - Agreeableness plateaus - **Extraversion starts to decline** — meaningfully, but not dramatically - **Openness starts to decline** — the fastest-dropping trait in midlife
The Openness decline is interesting. It contradicts the "wise elder" stereotype. What actually happens is that curiosity about completely new ideas and experiences drops with age; people consolidate around preferences they've developed.
What happens after 60 - Neuroticism continues to decline into old age — older people are, on average, emotionally steadier than younger - Extraversion drops faster — partly social network contraction, partly genuine trait change - Openness drops further - Conscientiousness finally plateaus
Contrary to stereotypes, older adults report higher life satisfaction and lower negative affect than younger adults across most studies. The personality drift fits this.
What stays stable **Rank-order stability.** If you're more Extraverted than your sibling at 25, you probably still are at 55 — even though both of your absolute scores likely declined. The rank between people is much more stable than individual absolute scores.
**The core self.** People reliably report feeling "like the same person" across decades even as trait scores shift. The changes are real but gradual enough that subjective continuity holds.
What accelerates change - **Becoming a parent** — spikes Conscientiousness and Agreeableness - **Starting a first demanding job** — spikes Conscientiousness - **Stable long-term relationships** — lower Neuroticism, higher Agreeableness - **Deliberate practice** — sustained behavioural change over 3+ months shifts trait scores (see our article on changing personality)
What can reverse change - **Unemployment for 6+ months** — reverses the Conscientiousness rise - **Chronic stress** — raises Neuroticism - **Social isolation** — reduces Extraversion more than aging alone does
What this means for self-knowledge If you took a personality test at 20 and retake it now at 35, a different result is not an error — it's real change. Most age-expected changes in this period: - Higher Conscientiousness - Slightly higher Agreeableness - Slightly lower Neuroticism
If your scores have moved in those directions, that's typical maturity. If they've moved away, something is worth examining — a demanding period, a bad relationship, prolonged stress.
How to use this - Retake the Big Five every 3-5 years to see your own trajectory - Don't treat a single test result as a permanent label - Don't expect dramatic overnight change — real personality change is measured in months, not weeks
Our 30-item Big Five test measures all five traits in 5 minutes. Take it, save the result, retake in a year.
