Linking early maternal input during shared reading to later theory of mind through receptive language and executive...

This study explored whether early maternal input during shared reading predicted later theory of mind (ToM) understanding through children's receptive language and executive function (EF). Maternal input plays a prominent role in the development of children's language skills, which are crucial for both EF and ToM development. There is also an abundance of behavioral evidence suggesting a directional link from EF to ToM. This relation raises the possibility of a cognitive cascade in which maternal input during shared reading promotes ToM development sequentially through receptive language and EF. The sample included 656 children clustered within 328 ethnically and sociodemographically diverse families. The shared reading sessions occurred when the younger and older siblings were 1.5 and 4 years old, respectively. Receptive language, EF, and ToM were measured when the siblings were approximately 5 years old to account for age differences. Multilevel modeling using Bayesian estimation was used to account for the effect of family-wide confounds (i.e., shared between the siblings in the family) while isolating child-specific processes (i.e., unique to each child within the family). The results supported two indirect paths from shared reading to children's ToM: one through receptive language alone and another that operated sequentially through receptive language and EF. These paths were observed only at the family level. These findings emphasize the importance of maternal input during early shared reading for cognitive development and suggest a cascade from maternal input to ToM via language and EF during the preschool period.