The capability to reflect on their own mental state and that of others continues to develop throughout adolescence, with mentalizing scores varying by gender and personality traits, according to a new study published this week in the open-access journal PLOS ONE by Alex Desatnik of University College London, U.K., and colleagues.

It has been established that the human brain undergoes a number of important changes during adolescence, especially in the "social brain" regions associated with social cognition. One of the key constructs capturing multiple facets of social cognition is mentalizing—the ability to reflect on one's own mental states and those of others, and talk about those mental states. Psychological mindedness is a partially overlapping construct referring to a personal ability to see relationships among thoughts, feelings and actions.

In the new work, the researchers analyzed data on 432 adolescents and young adults, ages 14 to 30, who were recruited from two independent schools and two universities. Participants completed a questionnaire that included the Reflective Functioning Questionnaire, often used as a measure of mentalizing, the Psychological Mindedness Scale, which gauges mindedness, and the Ten Item Personality Inventory.

The researchers found that mentalizing scores increased gradually over time and peaked in young adulthood. Across all age groups, females had consistently higher mentalizing scores than males. For females, scores increased the most between the age group 17–18 and the age group 20+ (effect size d=1.07, 95% CI 1.52–.62). For males, scores increased both between age 14 and the age group 15–16 (d=0.45, 95% CI .82–.07) and between the 17–18 and 20+ age groups (d=0.6, 95% CI 1.08– 0.1). Similar trends in score increases were seen for psychological mindedness. Significant positive correlations were found between mentalizing and the personality traits of Agreeableness, Openness to Experience, and Conscientiousness.

The authors conclude that mentalizing and psychological mindedness capacities mature in line with developmental changes throughout adolescence and into early adulthood. Moreover, the data suggest that age, gender, and personality traits should all be considered to establish a fully integrative picture of social-cognitive development in adolescence.

The authors add, "Our new research sheds light on continuous development of social understanding from age 14 well into our 20s, and associated gender differences, with impacts for mental health and education."