Collaborative Mother-Toddler Communication and Theory of Mind Development at Age 4.

Focusing on social pragmatics, this longitudinal study investigated the contribution of mother-toddler collaborative communication to theory of mind (ToM) development at age 4. At age 2½, 78 toddlers' (42 boys) and their mothers were observed during pretend play. At age 4, children were tested using 4 false belief understanding tasks. Both mothers and toddlers engaged in more collaborative (inform, guide/request, and support/confirm) than non-collaborative communication acts. Other-focused collaborative acts of support/confirm by mothers and toddlers predicted children's false belief understanding, even after controlling for 5 covariates. In addition, as active agents in their own ToM development, the contribution of toddlers' collaborative acts to false belief understanding was independent of their mothers. Finally, the way toddlers and their mothers co-constructing their communication mattered. Only when toddlers engaged in high levels of collaborative acts, the mothers' high levels of collaborative acts demonstrated a positive effect on children's ToM development. The applied implications of these findings were discussed.