Do people ever really change? The short answer is yes. Personality is not something that is completely static. In this article we will explore what can cause one’s personality to change and to what extent each trait is affected.
Aging
Personality has been found to change as people get older. One study used cross-sectional data to measure the differences in the Big Five personality traits for individuals from the ages of 10 to 65.1 This study found that from the age of 10 to around 15, Conscientiousness tends to decrease. Conscientiousness then rises more sharply from age 15 to the early 20’s and then rises more slowly from the 20’s onward. This change in Conscientiousness from adolescence through middle age equaled the difference between scores at the 50th and 86th percentiles of a normal distribution.
Agreeableness scores tend to decrease from age 10 until around 12-13. Agreeableness then shows a positive trend from adolescence until early adulthood, and continues to rise across early adulthood and middle age. The difference in Agreeableness between adolescence through middle age equaled the difference between scores at the 50th and 73rd percentiles.
Regarding Neuroticism, girls show a small increase in this trait from the age of 10 into adolescence with flat trends through early adulthood and then negative trends across early adulthood and middle age. This decrease is about the difference between the scores at the 50th and 32nd percentiles. For boys, Neuroticism decreases slightly from late childhood through middle age.
Extroversion decreases modestly from late childhood into adolescence and then remains flat throughout adulthood. This decrease is more pronounced for males (equaling about the difference between the 50th and 34th percentiles) than for females (equaling about the difference between the 50th and 42nd percentiles).
Lastly, Openness tends to decrease from late childhood to adolescence, and then rises across early adulthood through middle age. This total increase being about the difference between the scores at the 50th and 66th percentiles.
The study above provides evidence for changes in mean personality scores as individuals go from childhood into middle adulthood. However, most of these changes are only modest. Other studies which utilized longitudinal data have found that the Big Five traits tend to have high rank-order stability.2 This means that the ranking of one’s score in a group of people (such as being 65th percentile in Extroversion), tends to stay the same as when the group is retested years later.
Mindfulness and Psychedelics
Mindfulness-Based Cognitive Therapy (MBCT) has been shown to reduce Neuroticism in a pilot randomized study.3 MBCT teaches individuals to be aware of thoughts and feelings and to cultivate a non-judgmental, accepting attitude towards them. Greater awareness of one’s thoughts may help individuals notice unhelpful cycles of rumination and cultivate healthier processes such as self-compassion. In the study cited above, 17 individuals participated in an 8 week MBCT course which was delivered in weekly two-hour sessions. A control group of 17 individuals participated in an online-self help course. All participants scored high in Neuroticism at baseline. 4 weeks following the intervention, those who participated in the MBCT course showed significant decreases in Neuroticism compared to the control group. The mean score of Neuroticism for the MBCT group was 8.5 pre-treatment and 4.5 post-treatment.
Psychedelics, such as psilocybin (also known as “magic mushrooms” or “shrooms”), also have the potential to change one’s personality. In one study, 20 people who were suffering from treatment-resistant depression were given oral psilocybin (10 and 25 mg, one week apart) in a supportive setting.4 Their personality was assessed at baseline and then 3 months later. The study found that the individuals had statistically significant increases in their Openness (Cohen’s D of 0.437), Extroversion (0.716), and decreases in Neuroticism (-0.571). These results suggest that psilocybin has a medium effect size on personality 3 months after ingestion.
Given the small sample sizes of the above studies, more research is needed to better assess the link between these two interventions and personality changes.
Life Events
Another source of personality change are life events. Some life events have a much larger impact on personality than others. A recent study from the Journal of Personality analyzed how certain life events can impact one’s Big Five personality traits.5 A sample of almost 5000 people had their personalities measured and were asked about whether they experienced certain life events such as retirement or marriage. The participants were retested at a median interval of 35 days. These assessments took place over a period of time ranging from 3 to 40 months
Based on the data described above, the researchers calculated whether a life event would influence the rate of personality change over time or shift a person’s personality score. Overall, the study found that divorce had the largest effect on the rate of personality change with an average absolute value of standardized post-event slope mean of 0.83, followed by childbirth (0.39), retirement (0.36), getting engaged (0.36), and getting married (0.34).
The trajectory of Neuroticism increased in response to getting engaged (0.63), getting married (0.59), childbirth (0.48), and receiving a job demotion (0.35), and decreased in response to retirement (−0.76). The trajectory of Extroversion decreased in response to divorce (−1.33), retirement (−0.48), getting engaged (−0.40), getting married (−0.37), and starting to date someone new (−0.30), and increased in response to childbirth (0.40). The trajectory of Agreeableness increased in response to divorce (1.29) and getting engaged (0.41). The trajectory of Conscientiousness increased in response to divorce (0.54) and decreased in response to getting married (−0.42), receiving a demotion (−0.34), and childbirth (−0.32). Finally, the trajectory of Openness increased in response to divorce (0.71), childbirth (0.58), and finding out about a pregnancy (0.30).
Regarding personality score shifts, the authors measured an individual’s subjective experience of an event (whether they rated an event as a positive experience), and also took into account whether the life event’s influence on personality was transient (implying that the event effect was only present at one time point) or enduring. They then chose the model (subjective vs objective, transient vs enduring) that was the best fit for the specific personality trait and life event pair. For example an “ST” model would mean that the subjective experience of an event had a transient effect on personality.
Overall, the effect sizes on personality scores were small, with an average absolute value of the standardized event effect of 0.04. Levels of Agreeableness increased for people experiencing retirement (0.18; OT) and divorce (0.22; SE). For Neuroticism, the strongest event effect sizes were for divorce (−0.25; OE), moving to a new location (−0.15; ST), and receiving a demotion at work (−0.15; ST). The objective experience of divorce was associated with a persistent increase in Extroversion across the study period (0.17; OE). For Conscientiousness, the strongest event effect size was for getting married (0.07; SE). Lastly, job demotion (0.09; ST) and childbirth (−0.05; SE) had the largest effect sizes for Openness.
This study demonstrates that while life events can change one’s personality, these changes are usually small. In addition, some life events provide lasting changes in personality levels (such as divorce and Extroversion), while others only provide transient changes (such as job demotion and Openness). However, the results of this study should be interpreted with caution as the majority of the sample were women (82.26%), and the average age for the sample was 35. These results may not generalize to populations with different demographics.
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- Soto CJ, John OP, Gosling SD, Potter J. 2011. Age differences in personality traits from 10 to 65: Big Five domains and facets in a large cross-sectional sample. J. Personal. Soc. Psychol. 100:330–48 ↩︎
- Costa PT Jr, McCrae RR, Löckenhoff CE. Personality Across the Life Span. Annu Rev Psychol. 2019 Jan 4;70:423-448. doi: 10.1146/annurev-psych-010418-103244. Epub 2018 Sep 19. PMID: 30231002. ↩︎
- Armstrong, L. A., & Rimes, K. A. (2016). Mindfulness-based cognitive therapy for neuroticism (stress vulnerability): A pilot randomized study. Behavior Therapy, 47(3), 287-298.
https://doi.org/10.1016/j.beth.2015.12.005 ↩︎ - Erritzoe D, Roseman L, Nour MM, MacLean K, Kaelen M, Nutt DJ, Carhart-Harris RL. Effects of psilocybin therapy on personality structure. Acta Psychiatr Scand. 2018 Nov;138(5):368-378. doi: 10.1111/acps.12904. Epub 2018 Jun 19. PMID: 29923178; PMCID: PMC6220878. ↩︎
- Dugan, K. A., Vogt, R. L., Zheng, A., Gillath, O., Deboeck, P. R., Fraley, R. C., & Briley, D. A. (2024). Life events sometimes alter the trajectory of personality development: Effect sizes for 25 life events estimated using a large, frequently assessed sample. Journal of Personality, 92, 130–146. https://doi.org/10.1111/jopy.12837 ↩︎
