Simon Nicholson coined the term "loose parts" in 1971, arguing that the degree of creativity and inventiveness in any environment is directly proportional to the number of variables it contains. More than fifty years later, his theory has accumulated a substantial evidence base — and the research keeps pointing in the same direction: open-ended materials that children can move, combine, transform, and repurpose produce developmental outcomes that fixed, single-use toys simply can't match.
In 2026, that evidence is stronger and more specific than ever. We now understand not just that loose parts play works, but roughly why — and which types of materials produce which effects.
What counts as a loose part?
The definition is deliberately broad. Anything a child can move, combine, use in multiple ways, and give meaning to qualifies. This includes:
- Natural materials: sticks, stones, leaves, bark, pinecones, seed pods, sand, water, mud, shells, feathers
- Recycled and found materials: cardboard tubes, wooden spools, fabric scraps, jar lids, corks, wire, rope
- Construction materials: small blocks, planks, pipes, connectors, pegs
- Craft and sensory materials: clay, dough, sand, rice, paint, gravel
The unifying characteristic is that there is no prescribed outcome. A stick can be a wand, a bridge, a sword, a measuring tool, or a roof beam for a mud-and-leaf dwelling. That ambiguity is the feature, not a bug.
What research shows happens when children play with loose parts
Creativity and divergent thinking
A 2019 study in the Journal of Environmental Psychology compared children's play in standard playground environments against those with loose parts added. Children in loose parts environments produced significantly more original play scenarios, spent longer in sustained imaginative play, and engaged in more collaborative problem-solving. Interestingly, the researchers found that lower-cost materials (natural and found objects) produced stronger effects than purpose-designed "creative" toys.
Language and communication
When children are negotiating the shared meaning of a loose part — "this is the potion-maker, and you have to stir it three times" — they are doing sophisticated linguistic work. Research from the University of Cambridge found that loose parts environments generated markedly more complex language than structured play settings, including more conditional statements, more negotiation language, and more domain-specific vocabulary invented by the children themselves.
"Children with access to open-ended materials spend more time in deep play, use more complex language, and develop stronger social negotiation skills than peers in standard environments."
University of Cambridge, Play in Education, Development & Learning Research Group, 2021Risk tolerance and resilience
Loose parts — particularly natural ones — introduce manageable physical risk. A child balancing a plank, carrying a heavy stone, or figuring out how to stack irregular sticks is engaging in what researchers call "risky play": voluntary, child-directed challenges with uncertain outcomes. This type of play is consistently linked to stronger risk assessment skills, higher resilience in the face of failure, and better emotional regulation.
Social development
Loose parts are inherently social. Unlike single-use toys designed for individual use, loose parts create natural opportunities for collaboration, role assignment, and shared narrative. Children playing with loose parts spend more time in cooperative play and negotiate more successfully with peers than those in more prescriptive environments.
Natural vs. manufactured loose parts — does it matter?
The research here is nuanced. Natural materials — those with irregular shapes, organic textures, and no implied purpose — tend to produce the most open-ended play. A pinecone has no obvious "right" use. A branded block, even if versatile, carries some manufactured intention.
That said, the most effective loose parts environments tend to combine natural, recycled, and purpose-made materials. The key variable isn't the category of material — it's the degree of ambiguity and the number of transformation possibilities.
Setting up for loose parts play in your classroom
The most common mistake educators make is over-organising loose parts. Sorting stones by size into labelled bins imposes a logic on materials that the child should be inventing. Instead, consider:
- Offering materials in mixed collections rather than sorted categories
- Rotating materials seasonally to maintain novelty and introduce new textures and forms
- Including materials of different scales — some small enough for fine motor manipulation, some large enough to build with
- Ensuring outdoor access, where natural loose parts are most readily available and most freely used
- Resisting the urge to model or direct — demonstrate materials once if necessary, then withdraw
The furniture that surrounds loose parts play matters too. Low, open shelving at child height lets materials be accessed independently. Flat, solid surfaces — blocks tables, low platforms, outdoor decks — provide neutral building grounds. The Fern Kids approach to early childhood furniture starts from exactly this premise: that the room should enable independence, not require adult mediation for every interaction.
Addressing common concerns
"But children will fight over materials"
Yes, sometimes. That negotiation is part of the learning. Your role is to ensure enough material variety that competition is manageable, not to eliminate all conflict. Conflict resolution is a core social skill, and loose parts environments generate excellent conditions for practising it.
"Natural materials are a hygiene concern"
Natural materials require regular inspection and refreshing, particularly in infant and toddler rooms. Common-sense protocols — replacing materials that have been mouthed, washing hands before and after, avoiding materials with sharp edges or potential allergens — make outdoor and natural loose parts entirely manageable in any regulated centre.
- Loose parts generate stronger creativity, language, and social outcomes than single-use toys — and the research on this is now very strong
- Natural and found materials produce the most open-ended play — ambiguity is the key variable, not cost
- Avoid over-organising — sorted and labelled materials reduce the inventive possibilities that make loose parts work
- Conflict over materials is productive, not a failure — build in enough variety to keep it manageable
- Room design matters: low open shelving, flat surfaces, and outdoor access all amplify loose parts play
The simplest summary of fifty years of loose parts research: give children more stuff they can do more things with, and then leave them to it. The developmental returns are substantial, the cost is often minimal, and the play you'll witness will remind you why you do this work.