The Science of Behaviour: What’s Really Going on in Your Child’s Brain?

So often in modern society we hear tips about how to stop babies crying or how to get our children to become more independent - but that comes from a change in our culture - not a change in children’s brains. In this blog post I’m going to take you through a super simple guide to how your child’s brain develops and why we as parents need to understand the basics of that.

The Brain We Are Born With

Babies are born ‘unfinished’. Unlike a dog or a horse they aren’t born knowing how to walk or communicate in any other way than crying. In comparison to an animal, they develop incredibly slowly throughout childhood too. Our culture and society has made us stressed, rushed and pressured...but this doesn’t mean that our brains have learned to develop any quicker. In fact in many ways, our brains are still much like our ancestors. So despite what your to-do list may have you juggling, our brains weren't designed to be this busy.

How The Brain Develops

The brain has three major sections - the forebrain, the midbrain and the hindbrain. There are also lots of other parts like lobes, stems and systems, all of which are very important. But I don’t expect you to learn the names or really anything about each part, other than recognising the impact that it has on our children’s behaviour.

To make things easier when working with parents, and for the purpose of this post, I like to remember the word SET when it comes to the key parts of the brain. S/E/T which stands for Survival, Emotional and Thinking.

The forebrain at the top is our 'thinking' part, the midbrain handles our 'emotional' part and the hindbrain deals with all things 'survival'.

Are you ready? Because learning about the SET brain is about to explain everything you’ve ever wondered about your child’s behaviour.

The brain is like the headquarters of the human body. Thought to start developing just 2-3 weeks after conception, all parts of the brain are present from birth. This means that for many of us, our children's brains started developing before we even realised we were pregnant. The brain develops in sequence, the sequence being from the back to the front and from the inside out. So essentially, starting from the survival part of the brain.

At birth, the average baby’s brain is about a quarter of the size of the average adult brain but they'll be born with all of the brain cells (neurons) they’ll have for the rest of their life. However, it’s the connections between these cells that really make the brain work. Brain connections are developed through everyday experiences and they are what enable us to walk, talk, communicate, etc.

Fun Fact - from birth to around the age of 5, our little ones are producing more than a million neural connections (synapses) each second, which is more than at any other stage of their life!

The brain doubles in size in the first year of a child's life, hence why they need so much sleep and appear to literally change overnight! The baby's brain is shaped by their experiences, such as things they see, hear or engage with, which is why it is so important to spend time talking to them, showing our facial expressions and responding to their needs. As with any stage of childhood, a safe and caring environment is needed for optimal brain development.

During the second year, delicate nerve connections form patterns in brain. Children start to be able to plan their next move i.e putting blocks top of one another and showing frustration when they haven't been able to do something they'd expected to. The brain connections for language continue to form and we notice them talking more and more.

By the age of 3 the brain grows to about 80% of it’s adult size and the brain connections start to slowly reduce, making the brain more efficient. By the age of 5 the brain is 90% fully grown. Our children cannot explain all of the changes going on inside their bodies but from 0-5, and particularly 0-3, there’s so much going on (literally) inside their heads. Those toddler tantrums and overtired nights might make a little more sense now.

What can we as parents do to support this?

A child’s experiences in the first few years of life helps shape how their brain develops, having a lasting impact on their ability to learn and succeed as they get older. The early years really are the foundation for what is to come and as parents and carers we can make those foundations super strong. A young child’s daily experiences determine which brain connections develop, and, which will last for a lifetime.

The amount and the quality of care, stimulation and interaction a child receives during their early years makes all the difference as this is the best opportunity for a child’s brain to develop the all important connections. These connections are needed for many important, higher-level abilities like motivation, self-regulation and problem solving. They must be formed in these early years as it is much harder for these essential brain connections to be formed later in life. From a parent or carer perspective, it is imperative that we support our children with this development. As an example, the skills we teach in relation to their emotional intelligence will support them throughout adulthood too and I’ve written more about that here.

Why Does Brain Development Impact Behaviour?

The first part of the brain to develop is our S for Survival. This part of the brain is fully developed at birth and it’s called the Survival Brain because it literally keeps us alive. The survival brain automatically handles basic instincts and life sustaining functions such as breathing, heart rate, digestion, hunger, sleep, body temperature and balance. It is the part of our brain responsible for instinct and our fight/flight/freeze response. During the first year, a baby’s automatic behaviour is driven by the survival brain. The survival brain shapes a child’s view of risk and this is a large part of why their attachment to us is so important. This survival part of the brain has a huge influence over our children’s behaviour in the early years and will be a running theme as you parent them through early childhood.

The second tier is the mid-brain which deals with emotion and memory. For the purpose of this blog we are calling it the Emotional Brain (E). The Emotional Brain processes and regulates big feelings. This is also the part of the brain that helps them to form relationships. Memory, emotions, response to stress, separation anxiety, fear and rage are all located here. The emotional part of the brain determines how our children act if they sense danger. It’s worth mentioning here that danger could be being chased by a lion or someone stealing their favourite teddy. We must remember that our children's brains are still developing and this is where it stems from. This is where we might see 'act first, think later' behaviour – hitting, snatching or pushing for example. At this stage our children have not yet learned to control impulsive behaviour. This is why we need to remember that, even with our three to five year olds, we are likely to see lots of toddler behaviour. This is where we need to support emotional regulation. 

Then we come on to T, The Thinking Brain. The Thinking Brain is the last area to be established and this continues to do so through to our mid 20s. The mid 20s!!! This is why we can’t expect 4 year olds to behave like us, as even 14 year olds or 24 year olds may struggle. The Thinking Brain helps our children to think and learn, predict and plan. It's where our attention, creativity, self-awareness, understanding and interpretion of emotions all come from. It’s also the part of the brain where we find empathy, rational thought, problem solving and decision making and to reiterate again, this is still developing into our mid 20s. The Thinking Brain is the part that can distinguish right from wrong. This is where we find reasoning, imagination, kindness, logic and concern. Whilst there are said to be developmental spurts at approximately ages 5-6; 11-12; and around 15, we cannot expect children to tap into this thinking brain in their times of crisis. They aren’t able to use the same logic that we are, so we need to be realistic with our expectations of them.

So what happens now that you know all of this...

Over the next few weeks, when things crop up with your child, think back to the SET brain. Where is their behaviour coming from? Are there operating from the survival part of their brain? When they steal their sister's toy or scream in their brother's face, are they reacting from the survival brain? Do they feel threatened? Yes, probably. Is their reaction coming from their emotional part of their brain? You know, the one that cannot yet be rational? Yes, probably.

By seeing our children's point of view and recognising where in their brain they are reacting from, we can adjust our responses to support them and continue to support healthy brain development. Understanding that our children aren't yet able to consitently tap into their thinking brain, we can ask ourselves "where is this behaviour coming from" and "are we being realistic with our expectations/responses?"

If you've found this post interesting, leave a comment below! I'd love to hear what you think!

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Hi, I’m Emma, Early Childhood Expert and founder of Everyday. My goal is simple: help parents understand their children better, so connection deepens, guidance becomes clearer and every stage feels a little brighter. Because at the end of the day, it’s not about the extraordinary - it’s about the everyday.