Bilateral Coordination: Why Brick Play Is One of the Best Workouts for Both Hands Working Together
Your toddler is learning to make two hands work as a team — and the neuroscience behind why brick play trains this better than most activities will change how you see a simple stack.
Watch a 14-month-old attempt to hold a brick in one hand while reaching for another with the other. The whole body gets involved — shoulders shift, weight redistributes, tongue pokes out in concentration. This is bilateral coordination in action, and it is one of the most demanding tasks the developing brain undertakes in the second year of life.
What Bilateral Coordination Actually Means
Bilateral coordination is the brain's ability to synchronize both sides of the body toward a unified goal — one hand stabilizing while the other acts, or both hands working in mirrored or alternating rhythm. It underpins virtually every functional skill your child will develop: writing (one hand writes, one hand holds the paper), dressing (one hand pulls, one hand guides), eating with utensils, and eventually sports and self-care tasks.
Neuroscientists distinguish between symmetrical bilateral coordination (both hands doing the same action — kneading dough, rolling a ball between palms) and asymmetrical bilateral coordination (each hand doing something different — one hand stabilizing a container while the other pours). Asymmetrical is harder. Brick play with a purpose requires it constantly.
Why This Matters for Motor Development
The corpus callosum — the thick cable of neural fibres connecting the brain's two hemispheres — doubles in thickness between ages 2 and 4. Every time your toddler performs a task that requires both hands to do different things simultaneously, they're laying down additional callosal connections. These connections are the physical substrate of hemispheric integration: the neurological foundation for every task that requires coordination between spatial processing (right hemisphere) and verbal-sequential processing (left hemisphere).
In plain terms: every asymmetric brick task your toddler does is building neural infrastructure that will later support reading, writing, and arithmetic — not just physical coordination.
The Four Bilateral Coordination Stages in Brick Play
Stage 1 — Both hands doing the same thing
Your toddler holds two bricks, one in each hand, and bangs them together. Both hemispheres activated identically. This is the entry point — and it's valuable precisely because it's symmetric. The brain is establishing baseline motor programs for each hand separately before being asked to differentiate them.
Stage 2 — One hand stabilizes, one hand acts
A brick is held flat on the table by the left hand while the right hand positions another brick on top. This is the first asymmetric bilateral coordination challenge, and it requires the left hemisphere's sustained motor planning to maintain the stabilization while the right hemisphere's spatial processing guides the placement.
Stage 3 — Hands alternating in sequence
Stacking a tower: one hand places, the other hand reaches for the next brick, then they switch. Alternating hands requires the brain to sequence motor plans across time — a precursor to writing's letter-sequence production.
Stage 4 — Both hands on one object — different actions
Rotating a brick while pushing it onto a base plate: one hand rotates, the other provides downward pressure. This is one of the most demanding coordination tasks in early brick play and represents genuine integration of the two hemispheres working on a single object.
What You Can Do This Week
Stop intervening when your toddler's "method" seems inefficient. If they hold a brick down with their whole forearm rather than their hand while positioning another brick — they're not doing it wrong. They're working at the edge of their bilateral coordination ability. Offer challenges just slightly above their current capacity: a two-hand stabilization task (hold the base steady while building up), or an alternating-hand sequence task (stack three bricks, alternating hands).
The Short Version
Bilateral coordination — making both hands work together toward a single goal — is a foundational motor skill that develops between ages 1 and 4. Brick play requires asymmetric bilateral coordination earlier and more often than most toys: one hand stabilizes, one hand acts, or both hands alternate in sequence. Every time your toddler holds a base plate steady while building upward, they're training the neural connections between their brain's two hemispheres.