Demographic, Biological, Psychological, and Social Predictors of the Timing of First Intercourse

This study applied a biopsychosocial approach to examine the predictors of the initiation of sexual intercourse during adolescence. The sample included 157 boys and 268 girls, of whom 85.4% reported having had sexual intercourse by age 21 to 22. Participants were surveyed at 3 time points; once when they were 13 to 14 years old, again at ages 16 to 17 years, and again 6 years later. Proportional hazards regression was used to examine the relation of demographic, biological, psychological, and social predictors to the timing of first intercourse. In the biopsychosocial model, different factors significantly predicted timing of first intercourse for girls and boys. For girls, always-married parents and less dating alone predicted later timing of first intercourse. Earlier timing of first intercourse for boys was related to associating with peers with lower achievement orientation and greater importance of popularity.