MPIDR Working Paper
Childhood behavior and sexual debut in adolescence: a Danish National Birth Cohort study
Peters, S., Gaml-Sørensen, A., Ramlau-Hansen, C. H., Strandberg-Larsen, K., Torvik, F. A.,
Myrskylä, M. MPIDR Working Paper WP-2026-022, 62 pages.
Rostock, Max Planck Institute for Demographic Research (May 2026)
Abstract
Sexual debut is an important event in people’s lives, and it is linked with later physical and mental health. Previous research has examined the role of personal, family, and peer factors in explaining sexual behavior in adolescence. However, children’s emotions and behaviors, such as their internalizing, externalizing, and prosocial behavior, have been overlooked as potential determinants for sexual debut. We seek to fill this gap by linking behavioral indicators measured at age 11 with age at sexual debut. High-quality data from the Danish National Birth Cohort (DNBC) provide information on 27,456 adolescents who are followed from birth up to age 18. We apply accelerated failure time models and linear probability models to address our research question. Findings show that high internalizing behavior scores at age 11 are linked to later sexual debut for both boys and girls, whereas high externalizing behavior scores are associated with earlier sexual debut among girls, but not among boys. High levels of prosocial behavior are associated with earlier sexual debut among boys. The results are generally supported by dichotomous analyses on early sexual debut (before age 15). Our findings improve the understanding of sexual behavior in adolescence, and help identify adolescents who are at higher risk of having unwanted pregnancies and sexually transmitted diseases.
Keywords: Denmark, adolescence, sexual behavior