Psychologists sometimes joke that the majority of their studies are conducted on “Weird” people. By Weird, they mean individuals who live in western, educated, industrialized, rich, and democratic countries.
The joke, although not that funny for science, is that few studies make the effort to reach outside of this relatively narrow swath of humanity. And, by not including people of all regions and ethnicities in their research, the generalizations made by psychologists are not really all that generalizable.
But there’s another group that is equally underrepresented in psychological research: children and teenagers. It’s nice to see the occasional paper break the routine and explore a harder-to-reach demographic group.
A team of psychologists led by Cassandra Brandes of Northwestern University recruited the mothers of 440 children between the ages of 9 and 10 to engage in a multi-wave research project. The mothers’ task was simple: they were asked to complete a personality test on behalf of their child every year for four consecutive years.
The goal of the study was to explore early adolescents’ personality changes over time. Two hypotheses were at play. One, called the maturity principle, holds that as individuals grow from children into adults, they become more mature, pro-social, and self-regulated. They evolve into better versions of their kid selves. A competing hypothesis, called the disruption hypothesis, posits that the path from adolescence to adulthood is not a straight line and that adolescents exhibit antisocial behavior and dysregulation during this developmental stage.
The researchers were interested to see whether personality changes from age 9 to age 13 were more indicative of the maturity principle or the disruption hypothesis. To do this, they tracked the trajectories of five primary personality traits: extraversion, neuroticism, openness to experience, agreeableness, and conscientiousness.
Surprisingly, they found a remarkable degree of stability in these traits, at least as they were reported by the mothers. For instance, the trait of shyness, which the researchers categorize as a sub-component of neuroticism, was completely stable across the four-year time horizon. The traits of organization, intellect, considerateness, and positive emotions also showed little change.
There were, however, some traits that showed substantial change. Of the Big Five personality dimensions measured, agreeableness showed the highest degree of change — the 13-year-olds scored significantly higher on agreeableness compared with their 9-year-old selves. Furthermore, openness to experience decreased from age 9 to 13.
The authors also found four interesting gender differences. For instance, boys showed:
- Greater decreases in neuroticism
- Greater increases in considerateness
Girls, on the other hand, showed:
- Greater increases in extraversion
- Greater increases in achievement orientation
The authors state, “Overall, our results show that children’s personality matured to a small degree over the middle childhood period among self-regulatory facets that cross-cut higher-order domains, with disruption only evident among a single facet of openness to experience. These results provide more support for a continuation of personality maturity in the pre-adolescent period than they do for the disruption hypothesis, at least when measured via parent report.”
This work echoes some of the findings seen in the adult personality research literature, where there is a consensus that adults show gradual personality improvements over time. Research shows, for instance, that people are more optimistic in their fifties than they are in their twenties. People also tend to become more agreeable and conscientious as they get older. Even narcissists learn to tone it down over time, according to one study.
Brandes CM, Kushner SC, Herzhoff K, Tackett JL. Facet-level personality development in the transition to adolescence: Maturity, disruption, and gender differences. J Pers Soc Psychol. 2020 Nov 12. doi: 10.1037/pspp0000367. Epub ahead of print. PMID: 33180545.