Harmful Sexual Behaviour (HSB)
Understanding age-inappropriate or harmful sexual behaviour in children and young people, and how to assess and respond using evidence-based frameworks.
What is this?
Harmful sexual behaviour (HSB) refers to sexual behaviours in children and young people that are developmentally inappropriate, may be harmful to themselves or others, and may indicate abuse or trauma. Not all sexual behaviour in children is harmful — Brook's Traffic Light Tool provides a widely used framework for distinguishing between green (healthy), amber (concerning), and red (harmful) behaviours based on a child's age and developmental stage.
How it works
HSB exists on a spectrum. Green behaviours are healthy and age-appropriate (such as curiosity about bodies in young children). Amber behaviours are outside what is developmentally expected and require a closer look. Red behaviours are harmful, exploitative, or coercive and require an immediate safeguarding response. Children displaying HSB may themselves have experienced sexual abuse or been exposed to sexual content. Professional assessment is required before concluding that behaviour is harmful.
Warning signs
In your child's behaviour
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On their device
- • Accessing age-inappropriate sexual content online
- • Sharing sexual images with peers or receiving sexual images from adults
- • Using online platforms to initiate sexual conversations with others
Prevention steps
Use Brook's Traffic Light Tool
Brook's Traffic Light Tool is a widely used and evidence-based framework for understanding sexual development and identifying concerning behaviours. All staff working with children should be familiar with it.
Provide age-appropriate Relationships and Sex Education
RSE that is developmentally appropriate, accurate, and delivered well helps children understand consent, healthy relationships, and their right to bodily autonomy. This is a primary prevention measure for HSB.
Refer amber and red behaviours for professional assessment
Do not attempt to assess HSB without specialist support. Amber and red behaviours should be referred to your DSL and may require input from specialist services such as CAMHS or a specialist HSB assessment team.
What to do if it happens
- 1Do not overreact or shame the child, but do take the behaviour seriously. Record what you have observed and report to your DSL immediately.
- 2If the behaviour involves coercion or a significant age gap, treat this as a child protection matter and consider a referral to children's social care and the police.
- 3Seek specialist assessment through your local HSB pathway. Both the child displaying the behaviour and any child who has been harmed will require support — coordinate this through your DSL and the relevant agencies.
Related topics
This is practical educational content to support families. For case-specific concerns about a child's safety, contact the NSPCC helpline on 0808 800 5000 or your local safeguarding team.
Frequently Asked Questions
Related Resources
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Last reviewed: 2026-04-10