Watching a group of two-year-olds at a playgroup can be disorienting for adults who expect to see children playing together. Instead, they often seem to play alongside each other without interacting, competing for the same toy even when there are others available, or engaging with adults rather than peers. This is not a social failure — it is the normal developmental profile of the toddler years.
Understanding the sequence of social development in early childhood, and what is and is not developmentally expected at each stage, helps parents support their toddler's social experiences with realistic expectations and appropriate support.
Healthbooq supports parents with evidence-based guidance on social and emotional development in the early years, including the developmental milestones of social play and what to look for as children develop social skills.
The Stages of Social Play
Developmental psychologist Mildred Parten, writing in the 1930s, described a sequence of play stages that has remained influential in early childhood education and developmental psychology. While subsequent research has complicated the picture, the general sequence provides a useful developmental map.
Solitary play — playing alone, independently of others — is characteristic of early infancy and continues into toddlerhood, particularly in new or unfamiliar environments or when a child is tired or overwhelmed. It is not a sign of social difficulty; it is a normal and developmentally appropriate mode of play at all ages.
Onlooker behaviour — watching other children play without joining in — is common in younger toddlers and is an early form of social engagement; the child is learning about the play and the other children by observation, building the knowledge base for future participation.
Parallel play — playing alongside another child, often with similar materials, without direct interaction or shared purpose — is characteristic of the one-to-two-year period. Two children playing with blocks side by side, aware of each other but not cooperating or interacting directly, are engaging in typical parallel play. This is not a step short of "real" social play; it is an important developmental stage in its own right that allows children to experience the presence of peers without the demands of shared coordination.
Associative play — playing near others with some interaction (passing toys, brief exchanges, commenting on what the other is doing) but without shared goals or roles — typically emerges from around two years. Children begin to be interested in what others are doing and to interact around shared materials without coordinating a shared purpose.
Cooperative play — playing with a shared goal, complementary roles, and coordination of activity — is characteristic of the three-to-four-year period and beyond. This is what most adults picture when they imagine children "playing together," but it requires a level of theory of mind, communication, and impulse regulation that is simply not fully available to most toddlers under three.
Theory of Mind and Social Development
The development of theory of mind — the understanding that other people have separate minds, beliefs, desires, and perspectives that may differ from one's own — is central to social development. Classic theory of mind tasks (such as the false belief task, where a child must understand that another person will look for an object where they last saw it, not where it actually is) are typically passed at around three to four years.
Before theory of mind is consolidated, the toddler's social world is governed by a more egocentric understanding — not selfishness, but a genuine cognitive limitation in appreciating that others' experiences, beliefs, and desires differ from their own. This is one of the reasons why sharing, turn-taking, and negotiating conflicts are so difficult in the toddler years: these skills require understanding another person's perspective and prioritising it at the expense of one's own impulse.
Conflict Over Objects: Normal and Expected
The frequency with which toddlers grab toys from each other, refuse to share, and dissolve into conflict over objects that neither particularly wanted until the other picked one up is a source of frustration and embarrassment for parents. But this behaviour is neurologically and developmentally normal — not a sign of poor upbringing or difficult temperament. The combination of egocentric perspective, limited theory of mind, prefrontal immaturity, and the genuinely immature skill of perspective-taking makes sharing and turn-taking genuinely difficult, not a choice to be poorly managed.
Supporting social development at this stage involves close adult supervision in play situations, immediate and calm intervention when conflict escalates, and the gradual teaching of turn-taking language and concepts over months and years — not expecting toddlers to resolve conflicts independently.
Key Takeaways
Social development in toddlers progresses from solitary play through parallel play (playing alongside another child without interacting) to associative play (playing near others with some interaction but without shared goals) and eventually cooperative play (playing with shared purpose and roles). This developmental sequence is driven by neurological maturation, the development of theory of mind (understanding that others have separate mental states), and the accumulation of social experience. Most toddlers under three are developmentally oriented towards parallel and associative play rather than the cooperative play expected in older children; conflict over objects and turn-taking difficulties are normal at this age and not signs of poor social development.
