Harmful Sexual Behaviour

“The term ‘harmful sexual behaviour’ describes a continuum of behaviours displayed by children and young people under 18, ranging from those considered ‘inappropriate’ at a particular age or developmental stage to ‘problematic’, ‘abusive’ and ‘violent’ behaviours”. Centre of Expertise on Child Sexual Abuse – Key Messages (Feb ’23)

There is little data on the incidence of the full range of harmful sexual behaviours, however, current data suggests that children, ie. under-18s, are responsible for a significant proportion of child sexual abuse, and following on from the rapid review of sexual abuse, including peer-on-peer sexual harassment, sexual violence and online abuse in schools and colleges in England, carried out by
Ofsted, at the request the government found that sexual harassment and online sexual abuse were the two issues most commonly experienced and talked about by children and young people. The vast
majority of girls indicated that harmful sexual behaviours happened ‘sometimes’ or ‘a lot’ between people their age.

Among the most commonly reported behaviours were:-

  • sexist name-calling and comments
  • being sent or coerced into sharing sexual images.
  • Boys were also much less likely to think that harmful sexual behaviour affected them or their peers.

In younger children, behaviour is more likely to be at the ‘inappropriate’ or ‘problematic’ end of the continuum. Most young children displaying harmful sexual behaviour may have themselves been sexually abused or experienced other kinds of trauma or neglect.

The vast majority of harmful sexual behaviour involves children and young people who are well known to each other. It has been estimated that between a quarter and a half of harmful sexual behaviour involves siblings or close relatives such as cousins, nephews and nieces.

Boys are most represented amongst older young people who display harmful sexual behaviours and many of these children may also have a history of adverse childhood experiences and family difficulties.

It is important to remember that most sexually abused children and young people do not go on to abuse others, and the majority of children and young people displaying harmful sexual behaviour do not commit sexual offences as adults.

Professionals who work with children and young people should have the knowledge and skills to respond effectively to harmful sexual behaviour, and to support the creation of an environment safe from abuse.

What is harmful sexual behaviour?

Harmful sexual behaviour has been defined as sexual behaviour by under-18s that is “developmentally inappropriate, may be harmful towards self or others and/or be abusive towards another child, young person or adult”. Those either exhibiting or being harmed by such behaviours may be male or female. Behaviour that is ‘developmentally appropriate’ in young children may be concerning in adolescence, while other behaviours, normal in adolescence, would be worrying in younger children.

What is known about children and young people who display harmful sexual behaviour?

Pre-adolescent children

While the behaviour of some pre-adolescent children may be ‘problematic’, it is rare that these behaviours are intentionally abusive. Their behaviour may be a way of communicating what has happened to them or an indirect response to other factors in their lives, including other forms of abuse and neglect.


The early teen years are the most common time for the onset of harmful sexual behaviour.

Adolescents displaying abusive or violent sexual behaviour are, likely to have low self-esteem, poor social skills and difficulties with anger, depression and peer relationships and are often reluctant to engage with services.

When harmful sexual behaviour involves siblings, it may co-occur with domestic abuse and neglect. Compared with other intra-familial abuse, it may occur more often and over longer periods, and be more likely to involve intrusive and penetrative acts.

Outside of the family unit, sexual harassment and abusive behaviours between adolescents are so common in schools and colleges that some young people may regard them as ‘normal’. More highly abusive and violent sexual behaviour may occur in the context of delinquent groups or gangs, where sexual violence can be coerced as well as normalised.

Higher levels of antisocial behaviour tend to be shown by adolescents who behave in sexually harmful ways towards their peers, compared with those whose harmful sexual behaviour targets younger children.

It is important to remember that most victims of sexual abuse do not go on to abuse others, and that most children and young people who display harmful sexual behaviour do not go on to sexually offend as adults. However, older adolescents who abuse younger children, and those whose sexual behaviours involve violence, are at greater risk of further sexual offending.

Children with learning disabilities or autism

Children and young people with learning disabilities are more vulnerable both to being sexually abused and to displaying inappropriate or problematic sexual behaviour. However, it is likely that the high level of adult supervision of children and young people with learning disabilities means that their sexual behaviour is more likely to be observed and problematised.

Some children and young people with learning disabilities may be more likely to display harmful sexual behaviour as they may having less understanding that some sexual behaviours are not acceptable, and fewer opportunities to establish acceptable sexual relationships. They may also receive less sex education; struggle with social skills; and relate more easily to children younger than themselves.

Girls and young women

Harmful sexual behaviour tends to be identified at a younger age in girls than in boys, and tends to involve younger victims. It is rare for girls’ abusive sexual behaviour to involve the use of physical force. Girls displaying harmful sexual behaviour are less likely than boys to be charged with an offence, in part because they and their victims tend to be younger – but, like boys who display harmful sexual behaviour, they often have difficulties in school and relatively high levels of learning difficulties.

Technology-assisted HSB

The relationship between viewing pornography and subsequent harmful behaviours is likely to depend on the type and content of material viewed, the motivation for viewing, and factors such as age at first viewing and the intensity of viewing.

Effective assessment

There is a great deal of  support for the use of holistic assessment tools. These tools consider the specific risks of the child or young person’s behaviour (including online) and motivations, and their needs and strengths at individual, family and community levels. A number aim to assess the likelihood of harmful sexual behaviour persisting or escalating, but none has been validated as a predictive measure.

Assessments can take place for a variety of purposes: clinical, child protection or due to criminal justice consequences. It is important to remember that children and young people displaying harmful sexual behaviour are individuals, and the identification of the  ‘victim’ or ‘perpetrator’ may not always be clear. A careful and measured approach, should ensure that equals the seriousness of the behaviours seen and the context in which they happen.


Most prevention-focused activity takes the form of school-based programmes to raise awareness of; sexual exploitation, internet safety, consent and sexual harassment, and to promote healthy relationships. The rationale is generally that unhealthy attitudes and behaviours need to be addressed early, at an individual and at community and societal levels.


Interventions, like assessments should be proportionate to the nature and extent of the behaviour, and to the child or young person’s age and developmental stage; joined-up, multi-agency working and discussion is needed, to avoid agencies under- or overreacting to harmful sexual behaviour.

There are various assessments that are used when we have concerns about HSB. Some of these include AIM and the Sexual Behaviours Traffic Light Tool by Brook.

Both of these tools require practitioners to be trained in the use of the assessments/screenings.

Cheshire West & Chester and their Pan-Cheshire Partners have adopted the ERASE TOOL which has been developed by St Helens Safeguarding Children Partnership and have kindly given their permission to its adaptation to reflect local pathways.

This tool should only be used once you have attended a Cheshire West SCP ERASE Briefing or CW&C SCP Harmful Sexual Behaviour Training or you are being supported by a Safeguarding Lead who has undertaken this training.

There are instructions on how to use the tool, but if you are in any doubt, please speak to your manager or safeguarding lead.

Please note, St Helens have no objections in the sharing/circulation of this tool – but in these circumstances; have no responsibility in relation to the use of this tool.


Form-icon - Form Icon Png PNG Image | Transparent PNG Free Download on ...

ERASE CWAC version Updated Feb 2024