Patterns of fantasy play engagement across the transition to becoming a sibling.

Patterns of spontaneous dyadic fantasy play among 30 3- to 5-year-old first-born children who were becoming siblings were evaluated at two pre- and three post-birth intervals for its length, thematic content and social quality. Children who interacted more positively with their sibling played longer, engaged in fantasy play that was thematically relevant to becoming a sibling and had more positive interactions with best friends than low-sibling acceptance children. High-sibling acceptance children also experienced a suppression in fantasy immediately following their sibling's birth; thus, a temporary disruption in fantasy play may indicate adaptive coping.