A set of wooden blocks is, by most measures, the most educationally valuable toy a young child can own. Not because of marketing or parental enthusiasm, but because the evidence for what building with blocks develops across the first six years is genuinely impressive. The developmental return on investment – from a set of objects that have no battery, no screen, and make no electronic sounds – is hard to beat.
Healthbooq covers child development and play activities through the early years.
The Research on Block Play
The developmental benefits of block play are extensively documented. Work by Kimberley Sheridan at the University of Maryland and colleagues has confirmed the link between block play and spatial reasoning. Research by Harriet Romo at the University of Texas on longitudinal outcomes found that quality of block play at 3-4 years is a significant predictor of mathematics performance at school.
Dimitri Christakis at Seattle Children's Hospital conducted a randomised trial providing sets of unit blocks to families and found that children receiving blocks had superior language development compared to controls, likely mediated through increased parent-child interaction during building.
Lynn Cohen at Long Island University has documented the stages of block play and their relationship to architectural and engineering concepts that develop in formal schooling.
The connection to spatial reasoning is particularly important. Spatial skills – understanding three-dimensional relationships, mental rotation, spatial visualisation – are strongly predictive of performance in STEM subjects. Block play is one of the earliest and most effective ways to develop these skills.
Stages of Block Play
Block play follows a developmental sequence first described by Harriet Johnson at the Bank Street College of Education in New York in 1933 and confirmed by subsequent research:
Stage 1: Carrying and exploring (approximately 6-18 months). The young infant or toddler carries blocks from place to place, feels their weight and texture, bangs them, and mouths them. This is not "building" but it is active exploration of properties.
Stage 2: Stacking and rows (approximately 12-24 months). The first constructions: stacking blocks vertically (a tower) or arranging them horizontally in a row. Balance is discovered through falling towers. The child repeats the stacking, knocking down, and restacking cycle repeatedly.
Stage 3: Bridging (approximately 24-36 months). Two vertical blocks with a third laid across them – the bridge – represents a significant cognitive achievement. The child is now creating enclosed or spanned space, not just vertical or horizontal lines.
Stage 4: Enclosures (approximately 30-42 months). The child creates enclosed spaces: a house, a field, a fence around animals. This is the beginning of architectural thinking – using blocks to define and contain space.
Stage 5: Decorative patterns and symmetry (approximately 36-60 months). Structures become more complex and symmetrical; the child creates patterns and may add decorative elements. Evidence of aesthetic intention alongside structural function.
Stage 6: Representational building (approximately 48-72 months). Elaborate structures that represent known buildings: the school, the hospital, the family house. The child labels, narrates, and creates scenarios within the structure.
Choosing Blocks
Wooden unit blocks – specifically proportioned so that two half-units equal one unit, four quarter-units equal one unit, and so on – are the gold standard. The precise proportions allow increasingly complex mathematical relationships to be explored physically. Sets are expensive but last a generation and can be supplemented over time.
Magnetic tiles (such as Magna-Tiles) are excellent for older children (3+) who are ready for a different kind of spatial construction. Large interlocking bricks (Duplo/Mega Bloks) are appropriate from 18 months and develop similar skills with a different physical mechanism.
For the youngest children, soft blocks in varying shapes and sizes are safe and appropriate from around 6 months.
Key Takeaways
Block play is one of the most educationally valuable and versatile play activities across the first six years. It develops spatial reasoning, early mathematical thinking (symmetry, balance, quantity), problem-solving, and the persistence required to revise and rebuild when structures fall. Block play follows predictable developmental stages from carrying and stacking (6-18 months) through elaborate architectural building (4-6 years). Research consistently links the quality and extent of block play in early childhood with later performance in mathematics and spatial tasks. Wooden unit blocks remain the gold standard because they allow the most open-ended building.
