1. Teens
  2. Development
  3. Understanding your teenager

Teenage development: what to expect

12-18 years

The early teenage years see lots of changes – physical, emotional, cognitive and social. During this time, teenage bodies, emotions and identities change in different ways at different times.

Physical changes in teenagers

For girls, physical changes sometimes start happening as young as eight years, or you might see these changes only now, as your child enters the teenage years. Physical changes in puberty include:

  • breast development
  • changes in body shape and height
  • growth of pubic and body hair
  • the start of periods.

For boys, physical changes usually start around 11-12 years – but any time between 9 and 14 years is normal. Physical changes include:

  • growth of the penis and testes (testicles)
  • changes in body shape and height
  • erections with ejaculation
  • growth of pubic, body and facial hair
  • voice changes.

Emotional changes in teenagers

Now that your child is a teenager, you might notice that your child shows strong feelings and intense emotions at different times.

For example, your child’s moods might be unpredictable, and these emotional ups and downs can lead to increased conflict. This is partly because your child’s brain is still learning how to control and express emotions in a grown-up way. As your child moves through puberty, these emotional mood swings will begin to settle.

At the same time, your child might be more sensitive to your emotions. But while she’s learning to understand other people’s emotions, she might sometimes misread facial expressions or body language. She’ll get better at this as she moves into her later teens.

Your child is likely to be more self-conscious as he moves through the teenage years, especially about his physical appearance. Adolescent self-esteem is often affected by appearance, or by how teenagers think they look. As your child develops, he might compare his body with those of his friends and peers.

And your child might go through a stage of acting without thinking. Your child’s decision-making skills are still developing, and she’s still learning that actions have consequences and even risks sometimes. 

Your child’s body is maturing physically, but his brain development, thinking skills and emotional development are happening at their own speeds. What you see on the surface doesn’t always match what’s happening on the inside.

Social changes in teenagers

Young people are busy working out who they are and where they fit into the world. So you might notice that your child is searching for identity. For example, she’s trying out new or different clothing styles, music, art, friendship groups and so on. As your child gets older, her identity might become stronger, and you’ll get a sense of what kind of adult she’ll be.

Seeking more independence is common. Your child might want more responsibility too, both at home and at school. Getting a part-time job, choosing subjects to study at school, getting to social events by himself and changing extracurricular activities are all normal steps towards independence.

Your child might be more likely to look for new experiences, even risky ones. At the same time, she’s still developing control over her impulses. This has a lot to do with the way your child’s brain is changing in these years.

Your child is likely to be thinking more about ‘right’ and ‘wrong’. Your words and actions still shape your child’s sense of right and wrong. But as your child moves towards adulthood, he’ll have a stronger sense of his own personal values and morals.

You’ll probably find your child is influenced more by friends, especially when it comes to behaviour, sense of self and self-esteem.

Your child might also be starting to explore her sexual identity and sexuality. This might include romantic relationships or going out with someone special. These aren’t necessarily intimate relationships, though. For some young people, intimate or sexual relationships don’t happen until later on in life. 

The internet, mobile phones and social media can significantly influence how your child communicates with his peers and how he learns about the world. 


Teenage independence


In this short video, parents and teenagers talk about what age is appropriate for teenagers to do different independent activities. These include activities like getting to a friend’s house on public transport, going on an outing with friends, and catching the bus to school.

Parents talk about their concerns with increasing independence and the importance of staying in touch with what their children are doing.

Staying connected with your teenage child can be an important part of supporting your child’s social and emotional development. You can check out our Talking to Teens interactive guide to see how different approaches to staying connected can get different results.

Changes in teenage relationships

Your child’s relationships with family and peers will go through big changes and shifts. But maintaining strong relationships with both family and friends is important for healthy social and emotional development.

You might notice that your child wants to spend less time with family and more time with her friends and peers. If you find this hard, it might help to know that friends are more likely to influence your child’s short-term choices, like appearance and interests. Your influence is important on your child’s long-term decisions, like career choices, values and morals.

There might be more arguments with you. Some conflict is normal, because teenagers are seeking more independence. It actually shows that your child is maturing. Conflict tends to peak in early adolescence. Even if you feel like you’re arguing with your child all the time, it isn’t likely to affect your relationship with him in the longer term.

And it might seem like your child sees things differently from you now. This isn’t because she wants to upset you – it’s because she’s beginning to think more abstractly, and is questioning different points of view. At the same time, some teenagers find it difficult to understand how their words and actions affect other people. This will probably change with time.

Through all of this, a strong relationship with you is an important foundation for building your child’s resilience.


Adolescence and autism spectrum disorder


This short video features mums and dads of teenagers with autism spectrum disorder (ASD). They talk about how their child’s special needs affect development through the adolescent years. They say they can see their child’s social, emotional and physical changes. But when it comes to some behaviour, as one mum says, ‘Is it Ellis being a teenager, or is it the ASD?’

These parents agree that interventions like speech therapy and social skills classes have made a big difference to their child’s development.

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Raising Children Network is supported by the Australian Government. Member organisations are the Parenting Research Centre and the Murdoch Childrens Research Institute with The Royal Children’s Hospital Centre for Community Child Health.

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