Transactions between Personality Traits and First Sexual Experiences in Adolescence and Emerging Adulthood

There is some evidence linking personality traits to the experience of life events inadolescence and emerging adulthood. However, the role of one key life event marking theselife stages has not been examined within this context: the first sexual intercourse. Using 10-year longitudinal data from over 5,000 German adolescents and emerging adults (aged 14 to19 years at baseline), we examined the reciprocal associations between people’s first sexualactivity and the Big Five personality traits. Specifically, we examined whether personalitytrait levels predicted the timing of first intercourse (selection effects) and whether theexperience of first intercourse was related to subsequent personality trait changes(socialization effects). There was strong evidence that higher levels of extraversion predictedearlier first intercourse, with extraverted youth being more than three times more likely tohave experienced intercourse at baseline. In contrast, higher levels of agreeableness andopenness predicted a later onset of sexual activity. We also found some evidence forsocialization effects, suggesting mean-level decreases in extraversion in the years followingfirst intercourse, and distinct change patterns in openness depending on youth’s gender andrelationship status. Our findings highlight the predictive power of personality traits — andespecially extraversion — for a critical developmental experience like the first intercourseand how this milestone can reciprocally shape personality development. We discuss theresults with regard to personality development and relationship theories, integrating sexualmilestones into the study of life transitions and identity formation, while highlighting thedynamic interplay between individual traits and environmental influences.