Big Brothers/Big Sisters is a positive youth development program targeted in the community domain that demonstrates substantial behavioural outcomes for youth. This program sought to promote positive identity and competence by creating a strong bond with a healthy adult. These healthy adults, or mentors, committed a minimum of several hours, two to four times a month for a year with a youth that was carefully assigned to them based on their background, preference, and geographic proximity. Youths in this program improved in “school attendance, parental relations, academic performance, and peer emotional support.” Substance use and problem behaviors were also reported as either prevented or reduced.