Adolescent sexual activity in the family context: the impact of older siblings.

Using approximately 2,000 sibling pairs from the National Longitudinal Survey of Labor Market Experience of Youth, we examine the influence of an older sibling's age at first sexual intercourse on the sexual initiation of a younger sibling. Hypotheses about differences by gender composition of the pair are tested, using a framework derived from social comparison theory and a two-stage failure-time model. Results provide evidence of a direct but modest-sized older sibling effect for white but not black youth. This effect is approximately equal in magnitude for same- and opposite-sex siblings. Little support is offered for the greater salience and association of sexual activity for brother-brother as compared with sister-sister pairs.