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Bystander interventions to prevent sexual assault

Programmes that help young people to identify and intervene in potential sexual assaults

Estimated impact on violent crime:


Evidence quality:

1 2 3 4 5


1 2 3

Prevention Type

  • Primary


  • Community
  • School and college

What is it?

Bystander interventions to prevent sexual assault aim to empower and help children and young people to intervene in situations of potential sexual assault. They teach participants to identify early warning signs and safely intervene to prevent sexual assault from occurring. For example, they might teach participants to understand and notice controlling or abusive behaviour, or situations where someone is being exploited. They encourage participants to feel a sense of duty in these situations and give them concrete examples of things they can do or say to safely intervene. For example, starting a conversation with the potential victim or perpetrator, or physically intervening to prevent a potential victim being led away to an isolated place. Programmes explore attitudes and assumptions about sexual violence, sexual consent, empathy for victims of sexual violence, and myths about the role of victim behaviour in sexual violence.

These programmes typically work with children and young people aged 14 and above in secondary school, further education, or university settings. Activities could involve educational sessions delivered by a trained facilitator, role-play or discussion exercises, online educational videos, and school or university-based media campaigns, such as posters and leaflets.

There are several possible theories for why these programmes might prevent sexual violence. If programmes are successful at supporting young people to intervene then this could prevent incidents of sexual assault committed by young people’s peers and the broader public. An alternative explanation is that these programmes may reduce the likelihood of participants themselves committing sexual assault. Participants might be less defensive and more receptive to information if they are presented as part of the potential solution rather than potential perpetrators.  

Bystander intervention training is also used in the prevention of other forms of violence. This includes programmes where ‘violence interrupters’ intervene to prevent escalation of violent conflict between groups. However, this Toolkit summary focuses specifically on interventions to prevent sexual assault. The YEF plans to include other types of bystander intervention in the Toolkit in the future.

Is it effective?

The research on the impact of these programmes is complex. These programmes aim to support people to safely intervene to prevent potential incidents of sexual assault they might encounter in public or in their peer groups. Research suggests that programmes can be effective in supporting people to make this kind of intervention. However, research has not been able to measure the impact of this on instances of sexual assault by the wider public. It seems that this training can support children and young people to act but we don’t know whether these actions lead to fewer instances of sexual violence by other people.

The research is stronger on the impact of this training on participants’ own likelihood of perpetrating sexual assault. It suggests that bystander interventions are likely to have a moderate impact on reducing intervention participants’ own involvement in sexual assault.

The best available estimate suggests that these programmes could reduce participants’ involvement in sexual assault by 14%. 

How secure is the evidence?

We have low confidence in our estimate of the average impact on sexual violence.

Our confidence is low because there are only four studies that look at the impact of these interventions on sexual violence. All four studies were undertaken with boys and young men. None of these studies were from the UK. Three were from the United States and one from India.

There are three relevant studies from the UK, but they did not measure the impact on sexual violence or offending. The studies found positive impacts on participants’ knowledge and awareness of sexual violence and confidence to intervene in potential incidents. These include evaluations of:

  • The Intervention Initiative (TII) for 18-year-olds at university
  • Active Bystander Communities (ABC) for young people aged 16 and over in a community setting in Exeter
  • The Bystander Initiative for students in four universities in Wales

How can you implement it well?

Well-trained facilitators

The research suggests that programmes achieve greater engagement from children and young people when the facilitators are well-trained and confident in talking about sex, healthy relationships, and sexual violence. Sessions are generally more engaging and may lead to better learning outcomes when they include interactive exercises and promote discussions between children and young people.

Age-appropriate content

The content of these programmes should be appropriate to the age of the children involved. Children from different age groups will likely encounter different social situations and the content should reflect this.

More than one session

Some research suggests that programmes that involve more than one session may have a greater impact on changing attitudes towards sexual violence. Ideally, two or more sessions are delivered a few weeks apart, to provide time for reflection and informal discussions with peers.

Participant feedback

Interventions that challenge attitudes and beliefs related to gender stereotypes and the role of victim behaviour in relation to sexual violence can cause hostility, anger or pushback in a small number of people. This is called a ‘backlash effect’, where people with very strong beliefs react negatively to being introduced to new ways of thinking. It is important to regularly capture feedback from participants, formally or informally, to identify any individuals that may disrupt the process of creating shared attitudes and new peer-group norms about preventing sexual violence.

How much does it cost?

On average, the cost of bystander interventions to prevent sexual assault programmes is likely to be low

This estimate is based on programmes involving a single intervention through to a programme delivering up to three sessions that last approximately two hours. These sessions would usually be delivered by external facilitators or by trained teachers. Costs often include facilitator or staff time, travel costs, session materials and related media such as posters and leaflets. The cost per participant would likely be in the region of £250 – £500, assuming a minimum of 20 participants.

Topic summary

  • Bystander interventions to prevent sexual assault enable children and young people to develop the awareness, attitudes and skills necessary to safely intervene in situations of potential sexual assault.
  • These programmes are usually delivered by external facilitators or trained schoolteachers. They often involve interactive discussions, theatre, role-plays and poster campaigns.  
  • The available research suggests that this training can support children and young people to act but we don’t know whether these actions lead to fewer instances of sexual violence by their peers or the broader public.
  • There is more evidence on the impact on the participants’ own behaviour. This suggests that these programmes can have a moderate impact on preventing sexual violence.
  • Young people find sessions more engaging when there is a lot of interaction, and when facilitators have good knowledge and confidence in their delivery, and the content is appropriate for their age group.

Take away messages

  • Commission bystander interventions for children and young people aged 14 and above.  
  • Build in role play, group discussion and practice exercises. Deliver more than one session, with a break in between, to allow time for children to reflect on the content.  
  • De-prioritise bystander interventions programmes that only deliver a media campaign, such as using posters or leaflets to spread awareness.  

The Scottish Intervention Initiative Toolkit
A Toolkit to promote changes in the social environment to help prevent rape and sexual assault and domestic violence in university and further education settings.

Public Health England Guidance on Bystander Interventions  
Public Health England conducted a rapid evidence review that included bystander interventions to prevent sexual violence, and this guidance shares examples of interventions.

Welsh Women’s Aid Bystander Initiative Research Report
Research report evaluating the Bystander Initiative in four Welsh universities. This report calls for bystander intervention training to be provided to 16 to 18-year-olds.

College of Policing Briefing on Bystander Intervention Programmes
This is a 20-page briefing that summarises the evidence on the effectiveness of bystander programmes to prevent sexual assault among young people.