Comparisons across ages from 15 to 90 call into question the persistent belief that adult personality remains largely fixed.
Research: Personality traits are not as stable as people think. Image credit: Ribkhan / Shutterstock
In a recent study published online as a “press article” in the journal communication psychologyResearchers compared changes in personality traits to changes in other aspects of life.
Historically, personality traits have been thought to be largely stable and unchanging once a person reaches adulthood. Previous research suggests that personality traits develop throughout the lifespan, and provides promising initial evidence that personality traits can be modified through targeted interventions. The idea that personality is highly stable persists in the general public and in academic circles. The extent to which personality traits change compared to other aspects of life remains unclear.
About research
In the current study, researchers compared changes in personality traits over the lifespan to changes in other aspects of life. They conducted two studies. The first study investigated whether the general public believed that personality traits change less over time than variables from different areas of life. In the second study, we empirically assessed whether the average levels of population-level personality traits change less over the lifespan than the average levels of other variables.
In the first study, the final sample consisted of 887 civilians and was designed to be representative of the United States (US) population by age, gender, and race. Amateurs are people who do not have a Ph.D. in psychology. Participants rated on an 11-point sliding scale how much they believed the population mean level of a given variable changed on average from age 15 to age 90. Another “not at all” option was coded as zero. Specifically, there were 25 variables including the Big Five personality traits, health indicators, cognitive ability, income, engagement, leisure time, and social variables.
The team compared participants’ ratings of all individual variables with their aggregated ratings by domain, such as health and personality traits. The second study utilized secondary data from eight longitudinal studies conducted in the United States, Germany, the Netherlands, and Australia. These studies were representative panel studies, each with at least three Big Five data and 166,971 participants, all of whom had at least one Big Five data.
Researchers examined the Big Five alongside more than 30 other individual difference variables across the areas of health, finances/career, relationships, self and identity, engagement, leisure, and social functioning. The main standardized comparisons included 27 nonpersonality variables. The research team used a hierarchical age period cohort (HAPC) cross-classified random effects model (CCREM) to model the population-level lifespan mean trajectories of these variables. Finally, they derived meta-analytic lifespan trajectories for each variable and compared perceived and experiential lifespan changes.
Survey results
Layperson ratings of changes over the lifespan in the Big Five personality traits ranged from 4.58 to 5.87. Lay people rated neuroticism and extraversion as the most stable of the Big Five traits. Conscientiousness received the highest relative change rating. Change ratings for locus of control and self-esteem were average. Self and identity domains were rated as having average change. In contrast, the Big Five domains were rated as least variable.
The Big Five traits were all rated as significantly less variable than cognitive ability, self-esteem, locus of control, loneliness, life satisfaction, physical health problems, health status, health limitations, income, sleep, anxiety symptoms, leisure time, exercise, and social frequency. Participants rated the change in the Big 5 traits as 0.43 to 0.93 standard deviations less than their ratings on the other 20 variables.
Lay people rated the Big 5 domains as significantly more stable than other domains. Net change compared estimates at ages 15 and 90, and cumulative change summed the magnitude of all estimated yearly changes, regardless of direction. The second study found that among the Big Five traits, estimated mean levels of openness, neuroticism, and extraversion decreased overall from ages 15 to 90, but conscientiousness and agreeableness increased overall. Among the other 27 variables, positive emotions, leisure frequency, exercise frequency, and health status showed the largest net decreases.
In contrast, health limitations, BMI, physical health problems, and financial satisfaction showed the largest net increases. The Big Five traits showed net changes of greater or similar magnitude than many variables. The average annual cumulative change for the Big 5 traits ranged from 0.017 to 0.026 standard deviations, which corresponds to a total cumulative change of approximately 1.29 to 1.91 standard deviations from ages 15 to 90 years. Across variables, social frequency, income, health limitations, sleep, and conscientiousness had the largest cumulative changes in lifespan.
On the other hand, the smallest cumulative changes were in the importance of religion and economic and family satisfaction. Taken together, cumulative changes in personality traits over the lifespan were equal to or greater than several common variables.
Finally, lay perceptions of changes in lifespan were broadly consistent with meta-analytic estimates, although changes in personality traits were underestimated compared to other variables.
conclusion
In short, this means that populations are less stable in their levels of personality traits than commonly believed. The general public underestimated the degree of development of personality traits compared to other aspects of life. Long-term estimates show that these traits continue to develop throughout the lifespan, with average levels of change comparable in magnitude to changes in other aspects of life.
Modeled population-average trajectories do not indicate that all individuals change in the same way, that they represent the same people tracked continuously from age 15 to 90, or that people maintain their relative personality rankings over time. All data come from Western democracies, which may limit the generalizability of the findings.
These results highlight a persistent gap between empirical evidence and public perception about personality traits, and effective communication about flexibility may help close that gap.
