Blocks are possibly the most researched toy in educational history. From Friedrich Froebel, who placed wooden blocks (the "Froebel Gifts") at the centre of his kindergarten curriculum in the 1830s, to modern neuroscience research on spatial cognition, the evidence for unstructured block play in early childhood has accumulated steadily over nearly two centuries.
What makes blocks remarkable as a developmental tool is their openness. They do not have a correct answer. They do not make sounds when used correctly or light up to reward a specific action. They have a property — mass distributed in predictable geometric relationships — and everything else the child brings. That openness is precisely 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. Research by 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 block play at age three to four was a significant predictor of mathematical achievement at school age, even after controlling for IQ.
The mechanism appears to involve several distinct spatial skills: mental rotation (imagining how a shape will look from a different angle), spatial visualisation (understanding how parts relate to a whole), and perspective-taking (understanding that the structure looks different from different viewpoints). These are all exercised when a child plans how to balance a tower, creates an enclosure that requires pieces to fit together, or recreates a structure they have seen from a different angle.
Mathematical concepts are embedded in block play without any formal instruction. Children using unit blocks encounter: fractions (a half-unit is exactly half of a unit), area (filling a space), symmetry, pattern, length measurement, and number. Resnick et al. (2016) found that preschool block play time predicted performance on symbolic and non-symbolic mathematics tasks at age five.
Language development is also supported. Block play with an adult present and talking — naming shapes, describing spatial relationships, using mathematical vocabulary — creates a particularly rich context for vocabulary acquisition. Studies of adult-child interaction during block play find high rates of spatial and mathematical language that do not typically occur in other play contexts.
Fine motor skills and bilateral coordination develop through the precise manipulation required to balance and place blocks. The self-correcting nature of blocks — if the balance is off, the structure falls — provides immediate proprioceptive feedback that is valuable for motor learning.
Stages of Block Play
Harriet Johnson's classic study at Bank Street College (1933) described stages of block play development that remain broadly accurate:
Under one year: carrying and mouthing; blocks as objects to explore sensorially.
One to two years: stacking (typically two to four blocks high), beginning to line blocks in rows.
Two to three years: bridging (placing a block across a gap between two others), beginning to create enclosures, starting to name what they have built (often after building, not before).
Three to four years: elaborate structures with defined architectural features (towers, roads, buildings), beginning to plan before building, incorporating other toys and figures into block play.
Four to five years: complex structures, sophisticated representational play, detailed city plans and scenarios, collaboration with other children.
Types of Blocks
Wooden unit blocks (such as standard classroom-size blocks in half-unit, unit, double-unit, and quadruple-unit sizes) are widely considered the gold standard for developmental play. Their precise mathematical relationships (units that are exactly double, half, or quarter in different dimensions) allow children to explore fractions and proportional relationships concretely.
Soft foam blocks are appropriate for babies and toddlers under two. DUPLO and similar large-format interlocking bricks bridge the gap between free-stacking and more structured construction. Standard LEGO and similar systems require finer motor control and more following of instructions, reducing the open-ended spatial problem-solving that characterises unit block play.
Loose parts — natural materials like sticks, stones, shells, pinecones, and wooden offcuts — offer similar open-ended construction affordances without the mathematical precision of unit blocks, and have their own developmental value in terms of creativity and sensory exploration.
Making Block Play Rich
An adult who sits near, shows interest, provides spatial and mathematical language ("that's really tall — almost as tall as you," "I wonder how to make the bridge wide enough for the lorry"), and occasionally participates without directing is the most powerful addition to a block play environment. Questions that extend thinking ("What would happen if you put the big ones at the top?") are more useful than corrections or directions.
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.
