Transactions Between the Big Five Personality Traits and First Sexual Experiences in Adolescence and Emerging Adulthood

The first experience of sexual intercourse can shape relationships, self-concept, and social status, making it a potentially important milestone for personality development. Yet, little is known about how personality traits relate to the timing of first intercourse or whether this experience is associated with subsequent personality changes. Using data from more than 5,000 German adolescents (aged 14–19 years at baseline) followed for up to 10 years, we examined reciprocal associations between first intercourse and the Big Five personality traits. Extraverted youth were more than 80% more likely to have experienced intercourse at baseline and started about 7.5 months earlier than average, whereas agreeable and open youth experienced their first intercourse somewhat later. We also found some evidence for mean-level decreases in extraversion in the years following first intercourse, and distinct change patterns in openness depending on youth’s gender. The present findings highlight the predictive power of personality traits—and especially extraversion—for first intercourse and how this milestone can reciprocally shape personality development. We discuss the results with regard to personality development and relationship theories, integrating sexual milestones into the study of life transitions and identity formation, while highlighting the dynamic interplay between individual traits and environmental influences.