Toddlers’ symbolic play in dyadic mother-child and triadic mother-child-older-sibling interactions

Symbolic play supports crucial aspects of early childhood development, including language and social-cognitive skills. While research has established that parent-child dyadic play facilitates symbolic play development, less is known about how the addition of siblings (triadic interactions) is related to symbolic play development. Previous findings suggest that triadic play may present both opportunities and challenges for symbolic play development. We examined toddlers' symbolic play across dyadic (mother-child) and triadic (mother-child-sibling) free-play interactions. Twenty toddlers (aged 1.7-2.5 years, 8 girls) were observed playing with their mothers and older siblings (aged 3.5-7.5 years, 10 sisters) in two standardized 10-minute play sessions at their homes. We coded five dimensions of symbolic play: frequency, duration, variety, toddler initiative, and complexity. Consistent with our hypothesis, toddlers demonstrated significantly higher levels of symbolic play in dyadic versus triadic interactions overall (p < 0.0001, d = 0.953), and across all measured dimensions (p < .05 - p < .001, d = 0.637 - 0.915). These findings suggest that dyadic parent-child play may optimize conditions for symbolic play development, and/or that the addition of siblings introduces competing demands that reduce opportunities for advanced symbolic play. The results have implications for understanding how family configuration influences early play experiences, and may have implications for designing interventions to support symbolic play development in different social contexts.