18,333 Kilometres Apart, Still Growing Alike: The Magic of Development Across Hemispheres

A physiotherapist’s reflection on the universality of childhood movement.

When I decided to move from my home country of Wales to New Zealand, I knew many things would be new and different: the accent, the distance from family, the weather (thank goodness), and New Zealand’s famous landscape. But one thing that hasn’t changed at all is children’s movement.

I’m not sure what I was expecting—Kiwi kids do seem sportier, love the outdoors, and often run around barefoot—but when you observe their patterns of movement, nothing is different. Children growing up on opposite sides of the planet—literally the furthest population from my home in South Wales (sorry, Mum)—still roll, crawl, sit, walk, and run in the same way. They’ve probably never seen each other’s homes and experience entirely different cultures and climates, yet the way the human body learns to grow and move is universally the same. It’s a beautiful reminder of how clever our brains are—and what a miracle human development truly is. This realisation has only deepened my fascination with child development.

When we compare a human baby to other animals, we might initially feel underwhelmed. A kitten can forage independently within weeks of birth. A foal stands up moments after being born. Are human babies born prematurely by comparison? It certainly seems so. But look at what we become: from helpless infants completely reliant on caregivers to (arguably) the most intelligent beings on Earth. Sometimes we need a reminder of just how remarkable that is.

So how does it happen? How do we transform from a bundle of basic needs—food, sleep, comfort—into complex, thinking, moving beings?

Well, we never really stop looking for food, sleep, and comfort, do we? We just get better at doing it ourselves. At the heart of this transformation is the brain. But what teaches the brain?

Our body. "the body is the brain’s first teacher, and the lesson plan is movement." (Evans, 2014)

When we’re born, our brains contain around 200 billion neurons. Not all of them know what they’re for yet—only a few are “wired” for survival with instincts like breathing, feeding, and crying. The rest is a blank canvas. As we grow, we start painting that canvas through our experiences and movements. By the age of two or three, we have twice as many synapses (neural connections) as we’ll need in adulthood. By age five, 90% of our neural pathways are set for life.

Neuron networks neuron connections at birth

So how do we decide which pathways to keep?

Through a process called blooming and pruning. If we use a neural pathway repeatedly—for example, making a fist—it strengthens (blooms). If we don’t use it, the brain prunes it away. That’s why children are so good at learning—they can bloom and prune rapidly. As adults, we’re left with the pathways we chose to strengthen.

(To the avid gardeners out there—I know pruning can help things grow, but let’s keep the metaphor simple!)

This blooming and pruning process is part of something called neuroplasticity. Think of a pot of playdough. When it’s fresh, you can shape it easily. But if you leave it out, it hardens. It can still be shaped, but it takes more effort (as many parents can attest). That’s what happens to our brains as we age.

It all comes back to movement. Now, I know I’m a physiotherapist, so I might be a bit more into movement than the average person—but it’s everywhere, especially in infants. You might think newborns don’t move much. They can’t walk, after all. But even their small movements are meaningful signs of learning. How many of us have gotten excited at a baby’s first smile? Ever noticed the excited kicks that often come with it? How many pregnant mums have felt their baby wriggle at the sound of a familiar voice? We are wired to move.

Let’s return to the brain, with its layers, fluids, and—most importantly—nerve cells, or neurons. These little stars of development have two main jobs: storing and transmitting information. Neurons don’t physically touch; they rely on chemical signals to pass messages. So how do they know what to say?

That’s where blooming and pruning come in again. Neurons form new pathways when we practice movements. Take making a fist, for instance. At first, it’s just a reflex—like grabbing someone’s finger. But after practicing, we can grab things purposefully—our own hand, then a toy, then reaching out to grab something further away. These steps strengthen the neural pathways, until the movement becomes automatic. It's adorable when a baby figures out how to grab their own feet. Less adorable when they grab your hair before you know what's coming.

This speeding up of pathways is called myelination. Myelin is a fatty sheath that wraps around neurons, making signals travel faster and more efficiently. The more experiences a child has—emotional, physical, sensory—the more myelin is produced. This process typically finishes around age two.

Young children often know what they want to do before they fully understand why. They might reach for a toy without understanding its purpose. As they get older, they begin to connect the physical action to cognitive understanding. This is why balancing risk is so tricky. One day your child learns to open the toy cupboard—great! The next, they try to open the cleaning cupboard—not so great (cue childproof locks). Risk-taking is a necessary part of learning. If a child never wobbles while learning to sit, how will they understand where their balance lies? I'm not suggesting you let your baby fall, but let them wobble. Let them tip over a little—then catch them. The more they move and explore, the more they want to learn.

Children develop movement patterns from the top down and from the inside out—just like snowflakes forming as they fall, creating unique, intricate patterns. Babies gain head control before reaching for their feet. On their tummies, they push up on their arms before their legs. Over time, they go from curled-up newborns to stretched-out toddlers. There’s a scientific explanation for this: movement patterns travel from cephalo (head) to caudal (tail), gradually bringing control to the lower body.

Even as children grow, they don’t have to re-learn perception. As toddlers, they can easily grab objects on the floor. As they get taller, they might need to squat or reach further—but they don’t need to learn the task from scratch. Their coordination adapts.

A study once tested this by giving slopes to walkers and crawlers. The walkers, being older and more neurologically mature, attempted different strategies—like sliding down. The crawlers, though physically capable of sliding, didn’t attempt alternative strategies. This highlights a key idea: physical ability alone isn’t enough—cognitive development and cerebral maturation play a huge role in development too. Motor skills aren’t just learned through experience but also through brain development.

Across hemispheres, languages, and lifestyles, children grow in astonishingly similar ways. From South Wales to New Zealand, the patterns of movement, brain development, and exploration unfold with the same magic. Understanding this process—how the brain learns through the body—only deepens my appreciation for how incredible child development truly is.

REFERENCES

·       PNGKit, no date. Neuron networks neuron connections at birth [image]. Available at: https://www.pngkit.com/view/u2e6a9t4w7t4r5u2_neuron-networks-neuron-connections-at-birth/ [Accessed 13 Jun. 2025].

·       Neuroscientifically Challenged, no date. Myelin. [online] Available at: https://neuroscientificallychallenged.com/glossary/myelin [Accessed 13 Jun. 2025].

·       DK Find Out, no date. Nerve cells. [online] Available at: https://www.dkfindout.com/uk/human-body/brain-and-nerves/nerve-cells/ [Accessed 13 Jun. 2025].

·       Harari, Y.N., 2014. Sapiens: A brief history of humankind. London: Vintage.

·       Savelsbergh, G., Davids, K., van der Kamp, J. and Bennett, S.J., 2003. Development of movement coordination in children: Applications in the fields of ergonomics, health sciences and sport. London: Routledge.

·       Evans, G., 2014. A moving child is a learning child: How the body teaches the brain to think. San Francisco: Jossey-Bass.