Second Step is a social-emotional learning program that teaches social and emotional skills that facilitate emotion recognition and management, empathy, problemsolving, bullying prevention, and goal-setting. Existing research has shown that Second Step has reduced physical aggression in middle-school participants within a 1-year span. It has been rated effective in multiple studies. The current study examined the effect of participation in the program during middle school on a range of aggressive behaviors during participants' high-school years. Researchers also examined how connected students felt about their school, peers, and teachers ("school belonging"). Overall, this longitudinal study indicated that Second Step did not have a direct impact on outcomes during the high school years regarding bullying, sexual harassment, homophobic teasing, cyber bullying, teen dating violence, and substance use; however, the study showed that Second Step participants did improve students' sense of belonging across the middle-school years. This sense of belonging in middle school did apparently lower rates of some negative outcomes in high school, specifically bullying perpetration and victimization; being a victim of sexual harassment; perpetration and victimization of homophobic-teasing; and cyberbullying victimization. Thus, the distinction is made between the direct and indirect impact of Second Step after middle school students transitioned to high school. This was a seven-wave longitudinal study that included 1,565 students (males, 52 percent; White, 22 percent; African-American, 31 percent; Hispanic, 33 percent; and biracial, 11 percent). Fifteen Illinois schools participated.