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Sexual development and behaviour in children

Last updated: 28 Jul 2026
Introduction

It’s important that everyone who works with children and young people has a good understanding of how children develop sexually. This can help you recognise which sexual behaviours are developmentally typical and identify if a child is displaying behaviour that is problematic or harmful.

We’ve put together some information about the stages of typical sexual development and behaviour for different age groups. We’ve included examples of behaviour that is common and uncommon, and information about what to do if you are worried that a child is displaying problematic or harmful sexual behaviour.

Stages of child sexual development

All children go through phases of sexual development. Just like every other part of growing up, some children mature sooner or later than others. For example, some children may have developmental delays whilst others may reach puberty early.

In general, typical sexual behaviour should be:

  • playful and curious, not aggressive or angry (National Sexual Violence Resource Centre, 2013)
  • displayed towards children of a similar age, stage of development and physical size, who know each other well (National Sexual Violence Resource Centre, 2013; National Child Traumatic Stress Network (NCTSN), 2009)
  • voluntary and consensual (NCTSN, 2009).

Typical sexual behaviour should not cause physical or emotional harm to anybody involved (National Sexual Violence Resource Centre, 2013).

The tabs to the left contain some examples of typical sexual behaviour for different ages.

Healthy and unhealthy relationships

Learn how to recognise the signs that a young person is in an unhealthy relationship and what action you can take to help them.

Take a look

 

Under 5-years-old

Under 5-years-old

At this stage, it's common to notice natural exploratory behaviour emerging when children feel safe and comfortable. This includes:

  • having no inhibitions about nudity (National Sexual Violence Resource Centre, 2013; Virtual Lab School, 2021)
  • touching their own private parts (NCTSN, 2009; National Sexual Violence Resource Centre, 2013; South Eastern Centre Against Sexual Assault & Family Violence (SECASA), 2017; Virtual Lab School, 2021)
  • showing curiosity about other people's private parts or naked bodies (Healthy Children, 2019; NCTSN, 2009; National Sexual Violence Resource Centre, 2013; SECASA, 2017; Stop It Now, 2020; Virtual Lab School, 2021)
  • talking about bodily functions, using words like ‘poo’ and ‘wee’ (NCTSN, 2009, Virtual Lab School, 2021)
  • consensually role playing with their peers, exploring different relationships or roles such as ‘playing house’, ‘playing mummies and daddies’ or ‘playing doctor’ (Government of Canada, 2012; National Sexual Violence Resource Centre, 2013; Virtual Lab School, 2021).

Very young children can have erections, beginning from birth (Virtual Lab School, 2021).

It is uncommon for younger children to discuss specific sexual acts, use explicit sexual language or have adult-like sexual contact with other people (Stop It Now, 2007).

If you’re worried about a child’s sexual behaviour, you should act as soon as possible.

> Find out how to recognise and respond if a child is displaying problematic or harmful sexual behaviour

5- to 9-year-olds

5- to 9-year-olds

As children get a little older, it’s common to see them displaying behaviour like:

  • becoming more modest and asking for privacy (Government of Canada, 2012; SECASA, 2017; Virtual Lab School, 2021)
  • asking questions about sex and relationships, such as what sex is, where babies come from and same-sex relationships (Government of Canada, 2012; NCTSN, 2009; Stop It Now, 2007; Stop It Now, 2020; Virtual Lab School, 2021)
  • consensually exploring relationships with peers, for example mimicking adult relationships by holding hands with a ‘boyfriend’ or ‘girlfriend’ or giving them a kiss on the cheek (NCTSN, 2009; SECASA, 2017; Stop It Now, 2007).

As children become more aware of social norms and ‘rules’ around sexualised behaviour, it’s common for them to test boundaries. This might include using ‘naughty’ words they’ve heard from other people (NCTSN, 2009).

It’s uncommon for children aged 5-8 to have adult-like sexual interactions, discuss specific sexual acts or self-stimulate in public (Stop It Now, 2007).

If you’re worried about a child’s sexual behaviour, you should act as soon as possible.

> Learn more about problematic or harmful sexual behaviour and what to do if a child is displaying it

9- to 13-year-olds

9- to 13-year-olds

During these ages, children begin to get more curious about sex and relationships. They may start to be attracted to other people. Examples of typical sexual behaviour during this stage are:

  • having or wanting to have a romantic relationship with peers (of the same or different gender) (National Sexual Violence Resource Centre, 2013; Virtual Lab School, 2021)
  • using sexual language, making jokes about sex or discussing sexual acts with peers (SECASA, 2017; Stop It Now, 2007; Virtual Lab School, 2021)
  • wanting more privacy (National Sexual Violence Resource Centre, 2013; NCTSN, 2009; SECASA, 2017; Virtual Lab School, 2021)
  • looking for information about sex in books, online or in the media (this might lead to accidentally finding sexual pictures or videos) (Government of Canada, 2012; National Sexual Violence Resource Centre, 2013; NCTSN, 2009; Stop It Now, 2007; Virtual Lab School, 2021)
  • masturbating in private (National Sexual Violence Resource Centre, 2013; NCTSN, 2009; SECASA, 2017; Stop It Now, 2007; Stop It Now, 2020; Virtual Lab School, 2021).

It’s uncommon for children in this age group to display sexual behaviour in a public place, or regularly display adult-like sexual behaviour such as having oral or genital contact or intercourse (Stop It Now, 2007; 2020).

If you’re worried about a child’s sexual behaviour, you should act as soon as possible.

> Discover how to identify problematic or harmful sexual behaviour and what you should do in response

13- to 17-year-olds

13- to 17-year-olds

During adolescence, sexual behaviour becomes more private and young people begin to explore their sexual identity. You might notice them:

  • experimenting sexually and consensually with the same age group (SECASA, 2017; Stop It Now, 2007; Stop It Now, 2020)
  • looking for information about sex and sexual relationships (Stop It Now, 2007; 2020)
  • masturbating in private (SECASA, 2017; Stop It Now, 2007; Stop It Now, 2020).

The age of consent to engage in sexual activity in the UK is 16-years-old. However, the law is there to protect children from abuse or exploitation. It is not designed to unnecessary criminalise children.

It is uncommon for adolescents to masturbate in public, or display sexual attraction towards a much younger child (Stop It Now, 2007; 2020).

If you’re worried about a child’s sexual behaviour, you should act as soon as possible.

> Find out how to identify if a child is displaying problematic or harmful sexual behaviour

Schools, colleges and other education settings play an important role in teaching children and young people about healthy relationships.

> Find out more about how your school or organisation can prevent HSB and peer-on-peer sexual abuse

SEND/ASN/ALN

Young children (0-6 years) who have a learning disability or developmental delay usually experience sexual development and display sexual behaviour in similar ways to other children (Raising Children Network, 2025).

As children with a learning disability or developmental delay get older, they may experience sexual development differently to other children. This can sometimes lead to additional challenges for them (Holland-Hall and Quint, 2017). It’s important to think about a child’s sexual behaviour in terms of their developmental age, rather than their age in years.

Risk and vulnerability factors

Some children and young people who have a learning disability or developmental delay may find it difficult to understand and manage the changes that happen during sexual development. Due to a range of factors, they may display sexual behaviour that is considered inappropriate or problematic.

Education and information

A lack of accessible sex and relationships education and information may mean that children find it hard to understand the physical changes happening to them. It could also impact understanding of what a healthy relationship looks like.

Public and private behaviour

Some children might not understand or not have been taught the difference between public and private behaviours.

For some children with sensory-seeking needs, this may result in them touching or rubbing parts of their body such as their genitals in settings where this is considered inappropriate.

(McNeish and Scott, 2023; Raising Children Network, [2026]).

Emotions and communication

Children with a learning disability or developmental delay may find it difficult to manage their emotions. Any communication barriers children experience may mean that they also find it hard to express their emotions. Difficulty managing and expressing emotions can make it harder to understand and control sexual urges (Raising Children Network, [2026]).

A literal understanding of language or a lack of understanding of social nuances can also result in children not fully understanding how their actions may affect others and what other people may be thinking or feeling.

Relationships and boundaries

Struggles with social skills or relationships with peers their own age might result in a lack of understanding around sexual behaviour or social norms.

A lack of opportunity for relationships may mean that children have less experience and understanding of boundaries and what sexual behaviours are appropriate.

(IICSA, 2022; McNeish and Scott, 2023; Raising Children Network, [2026]).

> Learn more about problematic sexual behaviour

Responding to sexual behaviour

Professionals working with children who have a learning disability or developmental delay should be aware of their additional needs and challenges around sexual behaviour.

Sex and relationships education should be tailored to the specific needs of the child.

> See our Talk Relationships resources

Professionals need to listen to, support and communicate with children about sexual development and behaviour in a non-judgemental way that they can understand. Professionals should use children’s preferred communication tools to explore the topic.

> Find out more about helping children who have a learning disability navigate puberty and sexual development

Professionals also need to be aware that children and young people who have a learning disability or developmental delay can also be more at risk from sexual abuse and exploitation. People who sexually abuse children may target them because they see them as more vulnerable (IICSA, 2022).

> Learn more about safeguarding children who have disabilities

> Find out more about safeguarding children with SEND

References and resources

References and resources

References

Government of Canada (2012) When children act out sexually: a guide for parents and teachers. [Accessed 09/06/2021].

Healthy Children (2019) Sexual behaviours in young children: what’s normal, what’s not?. [Accessed 09/06/2021].

Holland-Hall, C. and Quint, E. H. (2017) Sexuality and disability in adolescents. Pediatric Clinics of North America, 64(2): 435-449.

Independent Inquiry Child Sexual Abuse (IICSA) (2022) Child sexual exploitation by organised networks: investigation report. [Accessed 27/07/2026].

McNeish, D. and Scott, S. (2023) Key messages from research on children and young people who display harmful sexual behaviour. [Accessed 27/07/2026].

National Child Traumatic Stress Network (NCTSN) (2009) Sexual development and behaviour in children: information for parents and caregivers (PDF). [Los Angeles]: NCTSN.

National Sexual Violence Resource Centre (2013) An overview of healthy childhood sexual development (PDF). [Alabama]: National Children’s Advocacy Center.

South Eastern Centre Against Sexual Assault & Family Violence (SECASA) (2017) Age appropriate sexual behaviours in children and young people: information for carers, professionals and the general public (PDF). East Bentleigh: SECASA.

Stop It Now (2007) Do children sexually abuse other children? Preventing sexual abuse among children and youth (PDF). Massachusetts: Stop It Now.

Stop It Now (2020) Tip sheet: age-appropriate sexual behaviour. [Accessed 09/06/2021].

Raising Children Network ([2026]) Children with disability: sexual development. [Accessed 27/07/2026].

Raising Children Network (2025) Sexual development and sexual behaviour: children with disability 0-6 years. [Accessed 27/07/2026]. 

Virtual Lab School (2021) Understanding normative sexual development & behaviour. [Accessed 09/06/2021].

Resources

Promoting healthy relationships

Provides tips on how you can promote healthy relationships to children of different ages or children who have special educational needs or disabilities. Aimed at the education sector but is also helpful for other sectors.

> Access our tips and guidance

Relationships and sex education (RSE) resources

We’ve put together a range of resources you can use to teach young people about relationships, health and sex education. Includes resources for children with special educational needs and disabilities.

> View the resources

Harmful sexual behaviour

Provides information on recognising, responding and preventing harmful sexual behaviour in children and young people.

> Learn more about harmful sexual behaviour

Recognising and responding to abuse

Outlines best practice for recognising and responding to abuse or concerns. Includes information about consent, reporting concerns, whistleblowing, mandatory reporting and more.

> Find out more

Podcast episodes

Listen to our short three-part series on responding to harmful sexual behaviour in schools, assessing sexualised behaviour and preventing harmful sexual behaviour.

> See all episodes

Training

Our elearning course will help you understand, respond and prevent incidents of harmful sexual behaviour.

> Find out more

Support for parents and carers

Many parents and carers may feel unsure about how to talk to their child or children about sex, sexuality and relationships. You can find advice to share with parents and carers on the NSPCC website.

> Read and share our advice for parents and carers

Support for children and young people

If a child or young person needs confidential help and advice direct them to Childline. Calls to 0800 1111 are free and children can also contact Childline online.

Childline provides information and advice for young people about sex and relationships.

You can also download Childline posters to share digitally or print and pin up around your building.