A Groundbreaking New Evaluation of Big Brothers Big Sisters

By Jean Rhodes

This summer, a rigorous four-year RCT of the BBBS community-based mentoring program reported findings that are incredibly promising. The study,  conducted by mentoring researchers David DuBois and Carla Herrera, represents the largest, most rigorous, and longest evaluation of Big Brothers Big Sisters to date. In it, they followed over 1,350 youth across 17 agencies for four years. Violence-related delinquent behavior occurred in 29.6% of the treatment group compared to 43.0% of the control group, recurring substance use was reported by 18.2% versus 31.4%, suicidal ideation affected 16.6% versus 28.4%, and only 3.1% of youth in the treatment group discontinued high school before graduation compared to 6.9% in the control group. The effect sizes represent the strongest outcomes ever documented for community-based mentoring. Most remarkable are the three large effects (Cohen’s d ≥ 0.50): for discontinuing high school before graduation (-0.512), recurring substance use (-0.438), and substance abuse (-0.430). Additionally, six medium effects (Cohen’s d 0.30-0.49) were observed, including suicidal ideation (-0.416) and violence-related delinquent behavior (-0.354). The remaining significant effects on more commonly evaluated outcomes (i.e., depression, positive affect, coping, academic performance, life satisfaction, social sills, negative peer associations) were small, ranging from 0.14 to 0.28 range. What makes these findings even more extraordinary is the fact that most matches met no more than twice monthly, with a substantial proportion meeting only once per month or less, representing a surprisingly low intervention dose for such strong outcomes.

Several factors may help to explain these unusually large effects.

Gender Effects: Despite a lack of gender-specific recruitment, there was a large proportion of male mentors (53.7%), substantially higher than the typical 34-36% found in most Big Brothers Big Sisters programs. The shortage of male mentors in youth-serving programs reflects a complex set of cultural and structural barriers that discourage men’s participation. Cultural suspicion around men in caregiving roles may contribute to men’s hesitancy to engage in close, supportive relationships with young people. Practical concerns may also play a role. Studies examining male volunteers’ motivations have found that men without prior mentoring experience often cite worries about time commitments, personal costs, and uncertainty about how to spend time with mentees as deterrents to volunteering (Hawkins et al., 2015). Perhaps the intial restrictions to online meetings reduced the psychological and logistical barriers to volunteering. Whatever the reason, this gender composition may have been particularly important given that most of the strongest findings were found in outcomes (e.g., violence-related delinquent behavior, substance abuse, school dropout) that tend to be  more prevalent among boys than girls. The availability of more male mentors likely meant better gender matches for at-risk male youth who might otherwise have remained unmatched or received cross-gender placements. The higher percentage of male Bigs may, in fact, reflect an unintended consequence of COVID-19 restrictions. When matches could meet virtually, potential male mentors may have felt more comfortable volunteering. Although face-to-face is important, this suggests that that a hybrid approach, at least initially, may reduce barriers to male volunteerism.

COVID-19 Effects: The study’s recruitment occurred from February 2018 to February 2020, with follow-up assessments conducted during and after the COVID-19 pandemic. This timing may have inadvertently created conditions for mentoring relationships to flourish. As youth lost access to teachers, coaches, extended family members, and other supportive adults due to pandemic restrictions, mentors may have become uniquely salient figures in their lives. Additionally, the shared experience of navigating pandemic challenges may have deepened mentor-youth connections, creating opportunities for authentic support during a time of universal stress and uncertainty.

Goal Effects: The study revealed that the vast majority (78.4%) of youth and most (59.4%) of parents reported that mentors were working with youth on achieving specific goals. This finding aligns with emerging research that has highlighted the importance of goal-focused approaches. Christensen et al., for example, demonstrated that targeted, goal-focused approaches to mentoring can yield effect sizes more than double those of purely recreational, relationship-focused programs.  The most commonly reported goals included social improvements (16.1%), academic improvements (15.9%), and increased self-esteem (15.6%). This structured approach may have provided the scaffolding necessary to translate caring relationships into measurable behavioral changes.

Sleeper Effects: Unlike previous Big Brothers Big Sisters RCT evaluations, which  followed youth for 18 months, this four-year study may have captured  “sleeper effects” from mentoring relationships. Several outcomes that showed no impact at the 18-month follow-up emerged as significant by the four-year mark, suggesting that mentoring benefits may require extended time to fully materialize. This pattern makes developmental sense. Mentoring relationships need time to form and deepen, and the skills, values, and perspectives transmitted through these relationships may not influence behavior until youth are older and face specific developmental challenges in later adolescence. The study’s longer timeframe allowed researchers to capture these delayed but meaningful impacts.

Technology Effects: As DuBois & Herrera point out, the agencies in this study utilized Customer Relationship Management (CRM) systems which enabled more intensive supervision and monitoring of mentor-youth relationships than was typical in earlier evaluations. These systems likely supported better match oversight, more consistent support from program staff, and earlier intervention when relationships encountered difficulties.

Implications 

These findings suggest several important directions for mentoring practice and policy. Perhaps foremost, the study was undertaken during an COVID 19, and need to be contextualized within that unique moment in our global history which may have led to stronger effects. Even so, there are lessons to be learned.

First, virtual and hybrid mentoring models deserve serious consideration, not merely as pandemic necessities but as potentially effective program formats in their own right. Although face-to-face is vital, balancing with online interactions may actually facilitate male mentor recruitment by addressing safety concerns during the early stages of the relationship while maintaining relationship quality.

Second, the goal-focused approach documented in this study should be widely adopted. Programs should invest in training mentors to help youth identify specific, achievable objectives and provide structured support for goal attainment. This represents a significant departure from the more relationship-focused approaches that have dominated community mentoring.

Third, programs should leverage technology platforms that enable enhanced supervision, goal tracking, and relationship monitoring. Systems that integrate evidence-based mentoring practices and goal setting with user-friendly interfaces can help programs scale effective practices while maintaining relationship quality.

Finally, program evaluations and funding decisions should consider the possibility of delayed but meaningful impacts that emerge years after relationships begin. Kudos to DuBois and Herrera for uncovering these remarkable findings!