Understanding Your Child’s Brain - Part 3

This is the third article in a four-part series exploring brain development and children’s behaviour. Together, we’ll look at some of the brain systems involved in survival, emotions, thinking and self-regulation, and how understanding them can help us respond to children with greater empathy and more realistic expectations.

REPTILE → MAMMAL → HUMAN → INTEGRATION

PART 3 OF 4 — THE HUMAN BRAIN: THE BRAIN THAT THINKS

🧠 HUMAN — COMPLEX THINKING & EXECUTIVE FUNCTIONING

→ Prefrontal cortex

→ Other interconnected cortical networks

→ Executive functioning networks

→ Brain systems involved in planning, working memory, attention, inhibition, flexible thinking, problem-solving and decision-making

A NOTE BEFORE WE BEGIN

The terms “reptile brain,” “mammal brain” and “human brain” are sometimes used as a simple way of explaining different brain systems and their functions. Modern neuroscience tells us that the brain is much more interconnected than this, and these systems do not work as three separate brains. They communicate and influence one another constantly.

In this series, I’m using these terms as a simple framework for understanding some of the major systems involved in children’s behaviour, while drawing on contemporary neuroscience to explain what is actually happening.

So, let’s move from the systems that help us feel, connect and remember to the systems that help us think, plan, solve problems and make thoughtful choices.

FROM FEELING TO THINKING

In Part 2, we explored the systems involved in emotion, emotional learning, memory and connection.

But your child isn’t only feeling. They are also gradually developing the ability to think about what they are feeling, pause, make decisions, solve problems and consider what might happen next.

This is where our “Human Brain” framework becomes useful.

WHAT DO WE MEAN BY THE “HUMAN BRAIN”?

In our framework, the Human Brain represents the more recently evolved cortical systems involved in complex thinking and executive functioning.

The prefrontal cortex is particularly important, but it doesn’t work alone.

Executive functioning involves interconnected networks that include the prefrontal cortex, anterior cingulate, parietal regions and hippocampus, among others.

These networks help us:

→ hold information in mind

→ focus our attention

→ inhibit impulses

→ shift our thinking

→ plan ahead

→ solve problems

→ make decisions

→ monitor our behaviour

→ regulate our responses

→ work towards a goal

These are the skills we often describe as executive functioning.

And if you’ve read my previous blog about executive functioning, you’ll recognise many of these skills already.

But here is the important part:

These abilities are still developing throughout childhood, adolescence and early adulthood.

THE BRAIN THAT THINKS IS STILL UNDER CONSTRUCTION

When we ask your child to:

• stop themselves from hitting

• wait for their turn

• remember a rule

• listen while someone else is talking

• think before acting

• solve a problem

• change their plan

• cope with disappointment

• control a strong impulse

• or consider how someone else might feel

we are asking their executive functioning system to do some pretty complicated work.

These abilities don’t appear all at once.

They are built gradually as the brain develops, through relationships, experience, practice and repeated opportunities to use these skills.

And this is one of the most important things I want you to take from this part of the series:

Your child may know what they are supposed to do long before they are consistently able to do it.

Knowing and being able to do are not always the same thing.

Children are not born with fully developed executive functioning skills.

They are born with the potential to develop them.

The early building blocks begin emerging during infancy, and we can see increasingly complex abilities developing throughout childhood. But these skills continue to mature through adolescence and into early adulthood.

This means your three-year-old, five-year-old or eight-year-old isn’t simply a smaller version of an adult.

Their brain is working with a developing executive functioning system.

And development isn’t a straight line.

Your child may be able to wait beautifully when they’re calm, but struggle to wait when they’re tired.

They may remember the classroom rule in the morning but forget it completely when they’re overwhelmed.

They may be able to use words to solve a problem with you one-on-one but become physically reactive when the same problem happens during a busy play situation.

This doesn’t necessarily mean that your child doesn’t know what to do.

Sometimes, it means that the brain systems needed to access and use that knowledge in the moment aren’t yet strong or flexible enough.

Harvard’s Center on the Developing Child specifically notes that young children’s difficulties with impulse control, attention, planning and emotional control should not simply be interpreted as intentional non-compliance; the neural systems supporting these abilities have a long developmental timetable.

EXECUTIVE FUNCTIONING: THE BRAIN’S AIR TRAFFIC CONTROL

I love the analogy used by the Center on the Developing Child at Harvard: executive functioning is a little like an air traffic control system.

Imagine an airport where dozens of planes are arriving and departing.

Someone needs to decide:

Which one goes first?

Which one needs to wait?

Where does it need to go?

What happens if something unexpected happens?

Your child’s brain is doing something similar.

It is constantly trying to manage:

attention + information + emotions + impulses + memories + plans + changing circumstances.

Executive functioning helps coordinate all of this.

And your child’s air traffic control system is still being built.

That makes a difference.

THREE CORE EXECUTIVE FUNCTIONING SKILLS

There are many aspects of executive functioning, but three core capacities are particularly useful for understanding children’s behaviour:

1. WORKING MEMORY

Working memory allows us to hold information in mind and use it while doing something else.

For example:

“Put your shoes on, then get your bag and wait by the door.”

For an adult, this might seem like a simple instruction.

For a young child, that’s several pieces of information that need to be held in mind while they actually carry them out.

And if something distracts them?

The information can disappear.

That’s not necessarily defiance.

Their working memory is still developing.

2. INHIBITORY CONTROL

This is the ability to pause an impulse and choose what to do next.

It is what helps us stop ourselves from:

• grabbing

• shouting

• pushing

• interrupting

• running off

• saying the first thing that comes into our head.

But here’s the catch:

Having an impulse and being able to stop an impulse are two different abilities.

Your child might genuinely understand: “I’m not supposed to hit.”

And still hit when their emotional system becomes highly activated.

The ability to inhibit that impulse is still developing.

3. COGNITIVE FLEXIBILITY

This is our ability to shift our thinking when things change.

It’s what allows us to think:

“That wasn’t the plan, but I can make another plan.”

For children, this might look like:

• accepting that the game has changed

• trying another way

• coping when someone says “no”

• moving from one activity to another

• considering another person’s idea

• changing a plan when something doesn’t work.

And this is often where we see the difference between knowing a rule and being able to flexibly apply it in a changing situation.

These three capacities (working memory, inhibitory control and cognitive flexibility) are central components of executive functioning.

BUT WHAT HAPPENS WHEN BIG FEELINGS TAKE OVER?

This is where Parts 1, 2 and 3 of our series begin to connect.

Your child’s thinking systems don’t operate separately from their emotional and survival systems.

When your child is calm, their developing executive functioning abilities may be much easier to access.

But when they are frightened, overwhelmed, extremely frustrated or emotionally flooded, the demands on these systems can become much greater.

Research on executive functioning highlights the extensive connections between the developing prefrontal systems and deeper brain systems involved in threat, stress and emotion. Strong stress responses can make it harder for children to use the executive functioning skills they have available.

So when your child is screaming:

“I CAN’T DO IT!”

the question isn’t always:

“Why won’t they use the skills they know?”

Sometimes the better question is:

“Are they able to access those skills right now?”

That small change in perspective can make a very big difference.

CHILDREN DON’T DEVELOP THESE SKILLS BY BEING TOLD TO “USE THEIR BRAIN”

Executive functioning develops through experience and practice.

Children need opportunities to practise waiting, remembering, shifting, planning, solving problems and managing impulses, with support from adults while those skills are still developing.

This is why co-regulation comes before independent regulation.

We don’t expect a young child to walk into a complicated situation and suddenly have the same emotional and cognitive control as an adult.

We support them.

We model.

We simplify.

We practise.

We give them another opportunity.

And gradually, with development and repeated experience, those skills become stronger and more accessible.

SO, WHAT DOES THIS MEAN FOR YOUR CHILD’S BEHAVIOUR?

It means we need to be careful about interpreting behaviour as a choice before considering capacity.

Your child might:

• know the rule but struggle to inhibit the impulse.

• understand what happened but struggle to find a solution.

• want to share but struggle to wait.

• know that yelling isn’t helpful but be unable to stop once overwhelmed.

• understand that plans change but struggle to flexibly adapt.

• know what they should do but need your support to actually do it.

This doesn’t mean that we don’t teach boundaries.

We absolutely do.

It means that teaching and expecting are not the same thing.

We can hold the boundary while recognising that the skill we’re asking your child to use may still be developing.

THE BRAIN IS BUILT THROUGH RELATIONSHIPS AND EXPERIENCE

One of the most encouraging things about the developing brain is that development doesn’t simply happen to children.

Children’s experiences help shape the development and strengthening of these systems.

Supportive relationships, opportunities to practise skills, predictable environments and appropriately challenging experiences all provide opportunities for children to build their developing capacities.

And this brings us back to something we have talked about throughout this series:

Your relationship with your child is part of the environment in which their brain develops.

When you help your child pause, you are giving them an opportunity to practise inhibition.

When you help them remember the steps, you are supporting working memory.

When you help them find another way when their plan doesn’t work, you are practising flexibility.

When you stay alongside them while they experience a big emotion, you are giving their developing brain an opportunity to practise regulation.

Little by little, the child doesn’t need us to do all of this for them.

The goal is not dependence.

The goal is development.

WHAT WE SOMETIMES EXPECT TOO SOON

Perhaps one of the biggest lessons from understanding the developing brain is this:

We can ask children to practise skills before they have fully developed them.

But we shouldn’t confuse practice with mastery.

A child who is still developing executive functioning will need:

more reminders

more repetition

more support

more opportunities to practise

and sometimes, simply, more time.

And that doesn’t mean we’re lowering our expectations.

We’re making our expectations developmentally appropriate.

Because when we understand what the brain is capable of right now, we can respond to the child in front of us rather than expecting them to operate with an adult brain.

AND THIS IS WHERE THE THREE PARTS COME TOGETHER…

We’ve now explored:

🦎 THE REPTILE — SURVIVAL & AUTOMATIC REGULATION

🐾 THE MAMMAL — THE BRAIN THAT FEELS

🧠 THE HUMAN — THE BRAIN THAT THINKS

But your child’s brain isn’t choosing between three different brains.

These systems are communicating all the time.

A frightening experience can activate survival responses.

Those responses interact with emotional systems.

And those emotional and survival states can influence how easily your child can access their developing thinking and executive functioning skills.

So what happens when all of these systems are working together?

That’s exactly where we’ll go in Part 4 — INTEGRATION: When the Brain Works Together.

And I think that’s going to be the part that brings the whole series together.

REFERENCES FOR PART 3

Center on the Developing Child at Harvard University. (2024). A Guide to Executive Function.

National Scientific Council on the Developing Child. (2011). Building the Brain’s “Air Traffic Control” System: How Early Experiences Shape the Development of Executive Function: Working Paper No. 11. Center on the Developing Child, Harvard University.

Center on the Developing Child at Harvard University. (2019). What Is Executive Function? And How Does It Relate to Child Development?

Center on the Developing Child at Harvard University. (2022). Brain-Building Through Play: Activities for Infants, Toddlers, and Children.

Center on the Developing Child at Harvard University. (2018). Three Principles to Improve Outcomes for Children and Families.