Blocks may be the most studied toy in educational history. From Friedrich Froebel placing wooden blocks (the "Froebel Gifts") at the centre of his kindergarten curriculum in the 1830s to modern spatial cognition research, the evidence for unstructured block play has accumulated steadily over nearly two centuries.
What makes blocks so unusually good as a developmental tool is how open they are. They have no correct answer, no electronic reward, no light or sound when you do something "right". They have one property — mass distributed in predictable geometric relationships — and the rest is whatever the child brings. That openness is exactly where the learning happens.
Healthbooq (healthbooq.com) covers play and development through the early years.
What Develops During Block Play
Spatial reasoning is the most consistently documented benefit. Casey and colleagues (2008) found that block play experience in preschool predicted spatial skills and mathematics achievement at school entry. Wolfgang, Stannard, and Jones (2001) found that the sophistication of a child's block play at age three to four predicted mathematical achievement years later in high school, even after controlling for IQ.
The mechanism involves several distinct skills working together: mental rotation (imagining a shape from a different angle), spatial visualisation (understanding how parts relate to a whole), and perspective-taking (knowing the structure looks different from where someone else stands). All of these get exercised when a child plans how to balance a tower, makes pieces fit together for an enclosure, or rebuilds something from memory.
Mathematical concepts are embedded in block play without anyone teaching them. Children using unit blocks bump into fractions (a half-unit is exactly half of a unit), area (filling a space), symmetry, pattern, length, and number. Resnick et al. (2016) found preschool block play time predicted both symbolic and non-symbolic mathematics performance at age five.
Language development also gets a boost — but mostly when an adult is nearby talking. Studies of adult-child interaction during block play show unusually high rates of spatial and mathematical vocabulary that don't typically appear in other play. "Underneath", "next to", "balance", "as long as", "half" — these words show up naturally when you're describing what's happening on the carpet.
Fine motor skills and bilateral coordination develop through the precise placing and balancing required. The structure is its own teacher: if the balance is off, it falls. That immediate feedback loop is excellent for motor learning.
Stages of Block Play
Harriet Johnson's classic study at Bank Street College in 1933 described stages of block play that have held up remarkably well in subsequent research:
Under one year: carrying and mouthing — blocks as objects to explore through the senses.
One to two years: stacking (typically two to four blocks high) and beginning to line blocks up in rows.
Two to three years: bridging (placing a block across a gap between two others), starting to make enclosures, and naming what they've built — usually after building, not before.
Three to four years: elaborate structures with defined features (towers, roads, garages), some planning before building, and bringing other toys and figures into the play.
Four to five years: complex structures, sophisticated representational play, detailed scenarios, and collaborative building with other children.
Types of Blocks
Wooden unit blocks — the standard classroom-size sets in half-unit, unit, double-unit, and quadruple-unit sizes — are widely considered the gold standard. Their precise mathematical relationships (where two halves equal exactly one unit, four quarters equal one, and so on) let children explore fractions and proportional relationships physically, without anyone calling them fractions.
Soft foam blocks are appropriate for babies and toddlers under two and survive being thrown, sat on, and chewed. DUPLO and similar large interlocking bricks bridge the gap between free-stacking and structured construction. Standard LEGO and similar systems require finer motor control and tend to come with instructions, which shifts the play toward following a plan rather than open-ended spatial problem-solving — both have value, just different value.
Loose parts — sticks, stones, shells, pinecones, wooden offcuts — offer similar open-ended construction without the mathematical precision of unit blocks. Their developmental value lies more in creativity and sensory exploration than in geometric reasoning.
Making Block Play Rich
The single biggest upgrade to a block play environment isn't a better set of blocks — it's an interested adult sitting nearby, occasionally narrating, and resisting the urge to direct.
The kind of language that helps: "That's really tall — almost as tall as you", "I wonder how to make the bridge wide enough for the lorry to fit through", "What would happen if you put the big ones at the top?" Open questions that extend thinking are more useful than corrections. Sit close. Show interest. Build sometimes, but on your own structure, not theirs. Let them be the architect.
Key Takeaways
Block play and construction activities support spatial reasoning, mathematical thinking, language development, and early engineering problem-solving. Longitudinal research has shown associations between block play in early childhood and later mathematics achievement. Block play also provides a rich context for adult-child mathematical and spatial talk, which is one of the most important predictors of early numeracy. Simple wooden unit blocks are developmentally superior to complex proprietary systems for young children because they require the child to plan, balance, and problem-solve without prompts from the toy itself.
