Guidebook

Big Brothers Big Sisters

Big Brothers Big Sisters is a mentoring intervention for children and young people aged 10 to 18 years old. It is delivered by a volunteer mentor to children and young people for a period of 12 months or longer, and aims to improve social, emotional, behavioural, and educational outcomes for children at risk due to social or economic disadvantage.

The information above is as offered/supported by the intervention provider.

Population characteristics as evaluated

9 to 16 years old

Level of need: Targeted-selected
Race and ethnicities: African American, Black, Hispanic, Native American, White.

Model characteristics

Individual

Setting: Community centre
Workforce: Volunteer mentor
Full evidence description (PDF)
View programme website
Evidence rating:
Cost rating:

Child outcomes:

  • Enhancing school achievement & employment
    • Improved school attendance
  • Preventing crime, violence and antisocial behaviour
    • Improved behaviour
    • Reduced involvement in crime
  • Preventing substance abuse
    • Reduced substance misuse
  • Supporting children’s mental health and wellbeing
    • Improved emotional wellbeing
    • Improved parent–child relationship
    • Improved prosocial behaviour

UK available

UK tested

Published: April 2025
Last reviewed: February 2025

Model description

Big Brothers Big Sisters (BBBS) is a mentoring intervention for children and young people between the ages of 10 and 18 years old. It is delivered in the community and aims to improve social, emotional, behavioural, and educational outcomes.

Big Brothers Big Sisters was developed based on the core assumption that a supportive and enduring friendship will develop and reinforce the positive development of a young person. This intervention is aimed at young people aged 10 to 18 years old who have experienced social or economic disadvantage, including those having poor social skills, being shy or withdrawn, having low self-esteem, or living in poverty.

Young people are matched to an adult volunteer, and the young person and ‘big brother or sister’ meet weekly to engage in social and recreational activities. The initial commitment is a minimum of 12 months. Once this relationship has been established, the intervention works to address the identified needs and goals of the young person. Goals may relate to learning a new skill or hobby, school attendance or academic performance, or developing social relationships. Activities are tailored to the young person’s desired goals, but may include: sport, cooking, board games, eating out, or going to an event.

Age of child

10 to 18 years old

Target population

Young people typically aged 10 to 14 years old (minimum/maximum age 6 to 18 years old) who come from disadvantaged backgrounds and meet the criteria for participation, including poor social skills, shy or withdrawn, low self-esteem, and economic or social disadvantage.

Disclaimer: The information in this section is as offered/supported by the intervention provider.

Why?

Science-based assumption

A disadvantaged background can negatively impact young people’s life chances, including poor educational and social-emotional outcomes, and increased chance of substance misuse and involvement in antisocial behaviour.

Science-based assumption

A mentoring relationship can provide a supportive role model and opportunities to learn new skills, and improve young people’s social-emotional competence, wellbeing, and educational engagement.

Who?

Science-based assumption

Children aged between 6 and 18 who experience low self-esteem, shyness/withdrawn, poor social skills, and/or economic disadvantage.

How?

Intervention

Mentors are recruited, trained, and matched with mentees.

Matches meet regularly to do social and recreational activities.

BBBS monitors and provides support for mentor–mentee relationships, including closure support.

What?

Short-term

Positive relationship with a supportive role model

Opportunities to develop new skills.

Medium-term

Improved social-emotional competence – improved relationship skills and social awareness

Improved mental wellbeing, including a greater sense of identity, social inclusion, and empowerment

Improved educational engagement, school connectedness, and commitment to learning.

Long-term

Improved mental health outcomes

Improved educational outcomes

Improved social outcomes

Reduced substance misuse

Reduced aggressive and problematic behaviour.

Who is eligible?

Young people typically aged 10 to 14 years old (minimum/maximum age 6 to 18 years old) who come from disadvantaged backgrounds and meet the criteria for participation, including having poor social skills, being shy or withdrawn, having low self-esteem, and experiencing economic/social disadvantage.

How is it delivered?

Big Brothers Big Sisters is delivered in weekly sessions where mentors are expected to meet with the child or young people on a one-to-one basis for one to two hours per week for a period of 12 months or longer.

What happens during the intervention?

  • BBBS staff match an adult volunteer to a child or adolescent. Once this relationship has been established, goals are identified through the intervention and activities are then delivered, tailored towards addressing the identified needs and goals of the young person.
  • The foremost goal of the intervention is the establishment of a mentor–mentee relationship, and other goals may relate to learning a new skill or hobby, school attendance or academic performance, or developing social relationships.
  • Goals are updated regularly by BBBS staff as progression occurs and circumstances change, and BBBS provide monitoring support to mentees to support the maintenance of the mentoring relationship.

Who can deliver it?

The practitioner who delivers this intervention is a Volunteer Mentor, supported by a Mentoring Programme Officer.

What are the training requirements?

  • The practitioners (volunteers) have 10 hours of intervention training. Booster training of practitioners is offered but not compulsory.
  • The mentoring intervention officers have 24 hours of intervention training. Booster training of 43.5 hours for mentoring intervention officers is recommended.

How are the practitioners supervised?

  • It is recommended that volunteer mentors are supervised by a clinical supervisor, with 67.5 hours of intervention training.
  • It is recommended that mentoring intervention officers are supervised by a case management supervisor with 67.5 hours of intervention training.

What are the systems for maintaining fidelity?

Intervention fidelity is maintained through the following processes:

  • Training manual
  • Other printed material
  • Other online material
  • Face-to-face training
  • Fidelity monitoring.

Is there a licensing requirement?

No

Contact details*

Contact person: Clare McPhillips

Organisation: Foróige

Email address: clare.mcphillips@foroige.ie

Website: https://www.foroige.ie/our-work/foroige-youth-mentoring-big-brother-big-sister

*Please note that this information may not be up to date. In this case, please visit the listed intervention website for up to date contact details.

Big Brothers Big Sisters most rigorous evidence comes from three RCTs conducted in the United States, so the intervention receives a Level 3+ rating overall. Additionally, one less robust RCT was conducted in Ireland.

Children in the intervention group showed statistically significant improvements across multiple outcomes. At post-intervention, there were reductions in arrests, substance use, depressive and emotional symptoms, peer and conduct problems, and antisocial behaviour. Statistically significant improvements were also seen in emotional and behavioural problems, parental trust, parent–child relationships, school attendance, and social support. Improvements in emotional wellbeing and social support, including support from other adults, were sustained at 18-month and 24-month follow-ups.

Big Brothers Big Sisters can be described as evidence-based: it has evidence from at least one rigorously conducted RCT or QED demonstrating a statistically significant positive impact on at least one child outcome, as well as at least one more RCT or QED.

Search and review

Identified in search15
Studies reviewed7
Meeting the L2 threshold1
Meeting the L3 threshold3
Contributing to the L4 threshold0
Ineligible3

Study 1

Study designRCT
CountryUnited States
Sample characteristics

1,358 families, with children aged between 10 years old and older, where families experience a form of social or economic disadvantage.

Race, ethnicities, and nationalities
  • 39% Black
  • 30% Hispanic
  • 24% White
  • 7% Other.
Population risk factors

Families who are experiencing financial hardship, family adversity (e.g. parental incarceration, mental health, or substance abuse issues), and potential behavioural or academic challenges.

Timing
  • Baseline
  • Post-intervention.
Child outcomes
  • Reduced arrest
  • Reduced substance use.
Other outcomes

None

Study rating3
Citations

Dubois, D., Herrera, C., Rivera, J., Brechling, V. & Root, S. (2022) Randomized controlled trial of the effects of the Big Brothers Big Sisters Community-Based Mentoring Program on crime and delinquency: Interim report of findings.

Study 2

Study designRCT
CountryUnited States
Sample characteristics

764 children aged between 9 and 14 years old where families experience a form of social or economic disadvantage

Race, ethnicities, and nationalities
  • 7% African American
  • 4% Hispanic
  • 2% White
  • 11.3% Other.
Population risk factors

Youth are typically from socioeconomically disadvantaged backgrounds, many of whom face risk factors such as single-parent households, financial hardship, and behavioural or emotional difficulties

Timing
  • Baseline
  • Post-intervention (13-month follow-up).
Child outcomes
  • Reduced depressive symptoms
  • Reduced emotional symptoms
  • Reduced peer problems
  • Reduced conduct problems.
Other outcomes

None

Study rating3
Citations

Herrera, C., DuBois, D. L., Heubach, J. & Grossman, J. B. (2023) Effects of the Big Brothers Big Sisters of America Community-Based Mentoring Program on social-emotional, behavioral, and academic outcomes of participating youth: A randomized controlled trial. Children and Youth Services Review. 144, 106742.

Study 3

Study designRCT
CountryUnited States
Sample characteristics

1,138 children aged between 10 and 16 years old

Race, ethnicities, and nationalities
  • 43% White
  • 57% Minority ethnic.

Of those from a minority ethnic background:

  • 71% African American
  • 18% Hispanic
  • 5% Mixed race
  • 3% Native American
  • 3% Other ethnic group.
Population risk factors
  • 90% of participants lived with only one of their parents
  • 40% lived in homes receiving public assistance or food stamps
  • 40% had family histories of substance abuse
  • 28% had family histories of domestic violence
  • 27% had experienced emotional, physical, or sexual abuse.
Timing
  • Baseline
  • Post-intervention (18 months).
Child outcomes
  • Improved social skills
  • Decreased substance use
  • Improved parental trust
  • Improved relationships and social support
  • Improved school attendance.
Other outcomes

None

Study rating3
Citations

Grossman, J. B. & Tierney, J. P. (1998) Does mentoring work? An impact study of the Big Brothers Big Sisters program. Evaluation Review. 22 (3), 403–426.

Study 4

Study designRCT
CountryIreland
Sample characteristics

164 young people aged between 10 and 16 years old who experienced some form of social or economic disadvantage

Race, ethnicities, and nationalities
  • 87% Irish
  • 7% Irish Traveller
  • 2% Any other White background
  • 1% African
  • 1% Any other Asian background
  • 1% Other.
Population risk factors
  • 46% of the youth did not live with both parents
  • The most common reasons for referral were that the young person was affected by economic disadvantage, had poor social skills, or was shy and withdrawn.
Timing
  • Baseline
  • Post-intervention (12 months after baseline)
  • Six-month follow-up
  • 12-month follow-up.
Child outcomes
  • Improved relationships and social support
  • Improved emotional wellbeing.
Other outcomes

None

Study rating2
Citations

Dolan, P., Brady, B., O’Regan, C., Brumovska, T., Canavan, J. & Forkan, C. (2011) Big Brothers Big Sisters (BBBS) of Ireland: Evaluation study. Report 1: Randomised control trial and implementation report. UNESCO Child and Family Research Centre, National University of Ireland Galway.

No other studies were identified for this intervention.

Note on provider involvement: This provider has agreed to Foundations’ terms of reference (or the Early Intervention Foundation's terms of reference), and the assessment has been conducted and published with the full cooperation of the intervention provider.

Cost ratings:

Rated 1: Set up and delivery is low cost, equivalent to an estimated unit cost of less than £100.

Rated 2: Set up and delivery is medium-low cost, equivalent to an estimated unit cost of £100–£499.

Rated 3: Set up and delivery is medium cost, equivalent to an estimated unit cost of £500–£999.

Rated 4: Set up and delivery is medium-high cost, equivalent to an estimated unit cost of £1,000–£2,000.

Rating 5: Set up and delivery is high cost. Equivalent to an estimated unit cost of more than £2,000.

Set up and delivery cost is not applicable, not available, or has not been calculated.

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Child Outcomes:

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Supporting children’s mental health and wellbeing: Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient.

Preventing child maltreatment: Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient.

Enhancing school achievement & employment: Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient.

Preventing crime, violence and antisocial behaviour: Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient.

Preventing substance abuse: Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient.

Preventing risky sexual behaviour & teen pregnancy: Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient.

Preventing obesity and promoting healthy physical development: Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient.

Evidence ratings:

Rated 2: Has preliminary evidence of improving a child outcome from a quantitative impact study, but there is not yet evidence of causal impact.

Rated 2+: Meets the level 2 rating and the best available evidence is based on a study which is more rigorous than a level 2 standard but does not meet the level 3 standard.

Rated 3: Has evidence of a short-term positive impact from at least one rigorous study.

Rated 3+: Meets the level 3 rating and has evidence from other studies with a comparison group at level 2 or higher.

Rated 4: Has evidence of a long-term positive impact through at least two rigorous studies.

Rated 4+: Meets the level 4 rating and has at least a third study contributing to the Level 4 rating, with at least one of the studies conducted independently of the intervention provider.

Rating has a *: The evidence base includes mixed findings i.e., studies suggesting positive impact alongside studies, which on balance, indicate no effect or negative impact.

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