Utilizing a stratified, random sample of 2,064 white adolescents, aged 14-17, living in Illinois, the proposition is evaluated that there have been substantial changes in the incidence of adolescent sexual experimentation and in the normative context which facilitates this activity. The data support intergender convergence, with the unanticipated finding that a substantial reduction in the incidence of male adolescent pre-marital coitus has occured. Other relationships with the incidence of coitus are also reported. (Author/EH)