A good set of wooden blocks may be the most educationally valuable toy a young child can own. That isn't marketing or parental nostalgia — it's what the evidence keeps showing. The developmental return on a set of objects with no battery, no screen, and no electronic noises is genuinely hard to beat.
Healthbooq covers child development and play through the early years.
The Research on Block Play
The case for block play is unusually well documented. Work by Kimberley Sheridan at the University of Maryland and her colleagues has confirmed the link between block play and spatial reasoning. Longitudinal work by Harriet Romo and others has found that the quality of block play at three to four years predicts mathematics performance at school.
A randomised trial by Dimitri Christakis at Seattle Children's Hospital — in which families were sent sets of unit blocks — found that children who received the blocks had stronger language development than controls, almost certainly because of the parent-child talk that happens around building.
Lynn Cohen at Long Island University has documented how the stages of block play map onto the architectural and engineering concepts that turn up later in formal schooling. The connection to spatial reasoning matters because spatial skills — three-dimensional thinking, mental rotation, visualisation — are among the strongest early predictors of later success in STEM subjects. Block play is one of the earliest and most accessible ways to develop them.
Stages of Block Play
The classic developmental sequence was first described by Harriet Johnson at Bank Street College of Education in New York in 1933, and it has held up well in nearly a century of subsequent research:
Stage 1: Carrying and exploring (around 6–18 months). The infant or toddler picks blocks up, carries them around the room, bangs them together, drops them, and puts them in their mouth. This isn't building yet, but it's an active investigation of weight, texture, sound, and what these objects do.
Stage 2: Stacking and rows (around 12–24 months). The first real constructions: blocks stacked into a small tower or laid out in a horizontal row. Balance is discovered the hard way, through falling towers, and then rediscovered, again and again. The build-knock-down-rebuild cycle isn't destruction; it's research.
Stage 3: Bridging (around 24–36 months). Two upright blocks with a third laid across them. This is a real cognitive leap — the child is now creating spanned space, not just vertical or horizontal lines. Bridging is one of the small developmental milestones that tends to surprise parents when they notice it.
Stage 4: Enclosures (around 30–42 months). The child encloses space: a fence around the toy animals, a house, a field. Architectural thinking begins — using blocks to define and contain rather than just to build up.
Stage 5: Decorative patterns and symmetry (around 36–60 months). Structures get more complex and noticeably more symmetrical. Patterns, balance, and decorative touches appear. There's now aesthetic intention alongside structural function.
Stage 6: Representational building (around 48–72 months). Elaborate structures with names and stories: "this is the school", "this is the hospital where my brother was born". The child labels, narrates, and runs scenarios with figures inside the structure. Block play now overlaps fully with imaginative play.
Choosing Blocks
Wooden unit blocks — proportioned so that two half-units equal one unit, four quarter-units equal one unit, and so on — are the gold standard. Those precise proportions let children explore mathematical relationships physically, long before anyone names them. A good set is expensive but lasts a generation, and you can keep adding to it over the years.
Magnetic tiles (such as Magna-Tiles) are excellent for older children from around age 3, opening up a different kind of three-dimensional construction. Large interlocking bricks (DUPLO, Mega Bloks) work well from about 18 months and build similar skills with a different physical mechanism — the snap-together connection lets children build taller and more elaborate structures than free-stacking allows at that age.
For the youngest children, soft foam or fabric blocks are safe from around six months and survive everything a baby will do to them.
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.
