The Seattle Social Development Project (SSDP) brought universal social skills intervention to some of the city's most urban schools. This study found that young adults who received SSDP interventions as young children still show positive effects 12 to 15 years after they outgrew the program.

The SSDP provided teachers and parents with training intended to help children participate actively in school and at home and receive encouraging reinforcement for their efforts. The theory is that a social skills program, such as SSDP, can help set kids on the road to functioning successfully as adults in school, at work and in the community. This analysis of the program's impact on participants years later is based on self-reports by 598 former students (93% of the original sample) who are now 24–27 years old. The mid-20s are a key age to adopt healthy adult patterns. The study also looked at results in relation to how much intervention participants received; some students received services in grades one through six and some received services only in fifth and sixth grade.

Key Findings:

• By age 27, those who received intervention were likely to earn more and have more education; do better on every indicator of school, work and community success; were significantly less likely to have ever been diagnosed with a sexually-transmitted disease; and were less likely to have mental health disorders.
• There appeared to be no effect of intervention on the rate of substance abuse and dependence.
• One finding, counter to the hypotheses, indicated that the full intervention group were slightly more likely, at age 27, to have committed a crime in the past year.
• Positive outcomes appeared in proportion to how much intervention children received; the "full intervention" model produced better results than the "late intervention" model.

The study was limited geographically, quasi-experimental and relied heavily on self-reporting by participants. But results indicate providing children with interventions to help them participate in the social and academic life of elementary school does seem to lead to more successful functioning in young adulthood. The authors regard the positive mental health indications as particularly important given how debilitating depression and anxiety can be throughout life.