Objective: To examine the long-term effects of the full Seattle Social Development Project intervention on sexual behavior and associated outcomes assessed at age 21 years.
Design: Nonrandomized controlled trial with long-term follow-up.
Setting: Public elementary schools serving children from high-crime areas in Seattle, Wash.
Participants: Ninety-three percent of the fifth-grade students enrolled in either the full-intervention or control group were successfully interviewed at age 21 years (n = 144 [full intervention] and n = 205 [control]).
Interventions: In-service teacher training, parenting classes, and social competence training for children.
Main outcome measures: Self-report measures of all outcomes.
Results: The full-intervention group reported significantly fewer sexual partners and experienced a marginally reduced risk for initiating intercourse by age 21 years as compared with the control group. Among females, treatment group status was associated with a significantly reduced likelihood of both becoming pregnant and experiencing a birth by age 21 years. Among single individuals, a significantly increased probability of condom use during last intercourse was predicted by full-intervention group membership; a significant ethnic group x intervention group interaction indicated that after controlling for socioeconomic status, single African Americans were especially responsive to the intervention in terms of this outcome. Finally, a significant treatment x ethnic group interaction indicated that among African Americans, being in the full-intervention group predicted a reduced probability of contracting a sexually transmitted disease by age 21 years.
Conclusion: A theory-based social development program that promotes academic success, social competence, and bonding to school during the elementary grades can prevent risky sexual practices and adverse health consequences in early adulthood.