Five to Thrive: Healthy brain development for all ages

Did you know your baby’s brain will double in size in the first year of their life?  

By the time they turn one, their brain will already be about two-thirds the size of an adult brain. This rapid growth happens because of the millions of new connections forming between brain cells. These connections shape how your child learns, feels, and relates to the world around them.  

Your baby needs strong brain cell connections to: 

• Feel happy and secure. 
• Build confidence. 
• Develop their speech and language. 
• Play and socialise. 
• Learn and become school-ready. 
• Be creative and solve problems. 
• Understand others’ feelings (empathy). 
• Manage emotions (self-regulation). 
• Bounce back from challenges (resilience). 
• Enjoy everyday life. 

Your baby is born completely dependent on you. One of the main ways they communicate is through crying or changes in behaviour. When you consistently meet their emotional needs by comforting, responding, and being present you help them feel safe. This emotional safety directly supports healthy brain development and lays the foundation for lifelong wellbeing. 

You can’t spoil a baby by giving them too much love or attention. In fact, every cuddle, smile, and soothing word helps build strong brain connections. 

At 12 months, your toddler’s brain is making trillions of connections. It’s in an exciting, and sometimes demanding, stage of growth. 

At this stage, your toddler:  

• Is becoming more mobile.  
• Enjoys doing things independently. 
• Is keen to investigate the world around them. 
• Will communicate more using single words, signs or gestures. 

Even though your toddler is becoming more independent, they still need you, especially when something feels tricky or when they want to share a moment of pride or joy. 

Their brain is still developing, which means they’re not yet able to: 

• Clearly express their needs in a way that’s easy to understand. 
• Fully grasp how others might feel. 

Because of this, your toddler may often feel frustrated, especially when they can’t do something, express themselves, or get what they want. This is completely normal and part of healthy brain and emotional development.

By the time your child is three years old, their brain is already about 90% of its adult size. This is a time of rapid growth not just physically, but emotionally, socially, and mentally. 

At this stage, your child will: 

• Become more adventurous and independent. 
• Start to express their thoughts, feelings, and ideas more clearly. 
• Begin playing with other children, rather than just alongside them - an important step in social development. 

Even though your child may seem more confident and may need fewer cuddles than when they were younger, you are still their safe place. Your presence, support, and attention remain essential to their wellbeing and learning. 

You can help your child feel capable and confident by encouraging them to try things for themselves, such as: 

• Helping prepare food - but be careful if there are sharp objects or hot things nearby. 
• Getting dressed. 
• Blowing their nose. 

These small everyday tasks build independence and self-esteem. And when your child feels good on the inside, they’re better able to understand their emotions and manage their behaviour. 

By now, your child’s brain is almost the size of an adult’s and with your emotional support, they’ve built a vast network of strong brain connections. These connections play a key role in how they think, feel, and respond to the world around them. 

They help your child to: 

• Manage their emotions and behaviour (self-regulation). 
• Cope with challenges and setbacks (resilience). 
• Understand other people’s perspectives (empathy). 

At this stage, your child may also be starting to: 

• Become more independent. 
• Explore ideas of right and wrong. 
• Show big emotions like frustration, excitement, or joy. 
• Sometimes act on impulse without thinking things through. 

These behaviours are a natural part of development, as their brain continues to grow and build the skills needed for emotional and social life. 

The teenage years bring one of the most significant periods of brain development since early childhood. The brain continues to grow and change right through the teenage years and into the mid-twenties. 

Every teenager is different, and their emotions and behaviour are shaped by a mix of brain changes, life experiences, and social influences. 

What happens during adolescence? 

Adolescence is the transition between childhood and adulthood. During this time, you may notice: 

• Better learning and thinking skills. 

• Growing need for independence. 

• A strong focus on friendships and social groups. 

• Intense emotions and mood changes. 

• More risk-taking or acting without thinking things through. 

• Increased tiredness and the need for more sleep 

Why do teenagers feel tired? 

There are many reasons a teenager may feel exhausted, including: 

• Not getting enough sleep. 

• Too much screen time, especially late at night. 

• Social stress (such as friendship worries, bullying). 

• Academic pressure or exam stress. 

• Changes in their brain. 

One of these changes is called brain pruning. This is when the brain clears away unused connections to make space for stronger, more useful ones. Most pruning happens during sleep, which is why teenagers need more rest than adults might expect. 

Teenagers and decision making 

Teenagers are asked to make big decisions about school subjects, careers, and friendships but the part of the brain responsible for planning and decision-making (the prefrontal cortex) isn’t fully developed yet. This can make choices feel overwhelming or lead to impulsive behaviour. 

How you can support your teenager 

Your emotional support continues to play a powerful role in shaping your teenager’s brain. The safer and more supported they feel, the more strong, healthy connections their brain can build. 

This support helps them develop their: 

• Self-regulation - how they manage emotions and behaviour. 

• Resilience – how they cope with challenges and setbacks. 

• Empathy - understanding and caring about how others feel. 

The brain continues to develop throughout life. With your guidance and understanding, your teenager can learn to navigate this complex stage and build a strong foundation for the future.