Developmental progression in play behavior of children between nine and thirty months. I: Spontaneous play and imitation.

The developmental progression of play behavior was studied cross-sectionally in 85 children at eight age-levels between nine and 30 months. In a structured play situation, three major play patterns were distinguished: (1) exploratory play (at the end of the first year); (2) functional play (beginning of second year); and (3) representational play (after 15 months). Sequential play first occurred at 21 months. Play behavior with spatial characteristics was also observed: relational and container play between nine and 15 months, and understanding of spatial relationships, stacking and grouping between 18 and 24 months. There was a significant relationship between spontaneous and imitative play behavior; the greatest affect was displayed when the demonstrated behaviors matched the child's developmental level of play.