Social distance and homophily in adolescent smoking initiation.

Background: Studies often demonstrate homophily in adolescent smoking behavior, but rarely investigate the extent to which this is due to the peer network processes of selection versus influence. Applying the concept of social distance, this study examines these two processes for smoking initiation.

Methods: We analyzed socio-centric network data from the National Longitudinal Study of Adolescent Health (N=2065; grades=7th-12th).