Working in the 1930s, researcher Mildred Parten grouped play into six categories and determined that children’s play styles mirror their social development. These stages are identified as:
- Unoccupied -- Not engaged in play.
- Solitary (Independent) -- Playing separately from others, with no reference to what others are doing.
- Onlooker -- Watching others play. May engage in conversation but not engaged in doing. True focus on the children at play.
- Parallel -- Playing with similar objects, clearly beside others but not with them (near but not with others.)
- Associative Play -- Playing with others without organization of play activity. Initiating or responding to interaction with peers.
- Cooperative Play -- Coordinating one’s behavior with that of a peer. Everyone has a role, with the emergence of a sense of belonging to a group. Beginning of "team work."