A social contagion model of adolescent sexual behavior: explaining race differences.

Black adolescents in the United States consistently report an earlier age of first intercourse than White adolescents. Purely psychosocial explanations of this finding have been less than successful. We propose an "epidemic" model that combines social contagion (a psychosocial process) and pubertal maturation (a biological process). This epidemic model permits social contacts among adolescents of the same age and also among younger and older adolescents. The model statistically fit the actual growth curve of sexuality well for Whites; its fit was not as good for Blacks. From computer simulation analyses, we concluded that pubertal maturation may be more important in accounting for the racial difference in the onset of sexual intercourse than previously thought.