We observed the play of 32 toddlers and preschoolers randomly assigned to eight play groups. Four of the play groups contained children of the same age; the other four contained children who were 2 years apart in age. No differences were found in overall patterns of play as measured by Parten's (1932) play codes. Although negative behaviors occurred infrequently in both settings, younger children tended to exhibit more negative interactions in same-age settings, and older children exhibited more negative interactions in mixed-age settings. Younger children in mixed-age settings played with same-age and older playmates at expected rates; older children in mixed-age settings, however, were more likely to choose other older children as playmates. The results, which differ to some extent from previous research, may be due to the familiarity of children with peers within the group and common day-care experiences prior to the study.
Social interactions of toddlers and preschoolers in same-age and mixed-age play groups
Bailey, D., McWilliam, RA., Ware, WB., & Burchinal, MA. (1993). Social interactions of toddlers and preschoolers in same-age and mixed-age play groups. Journal of Applied Developmental Psychology, 14(2), 261-276. https://doi.org/10.1016/0193-3973(93)90036-U