This study investigated relations among children's Theory-of-Mind (ToM) development, early sibling interactions, and parental discipline strategies during the transition to siblinghood. Using a sample of firstborn children and their parents (N = 208), we assessed children's ToM before the birth of a sibling and 12 months after the birth, and…

The present study investigated children's internal state language during play with their sibling and friend across early and middle childhood. Specifically, the category type of internal state language (e.g., cognitions and goals), referent (e.g., own and other), and associations with children's birth order were examined. A total of 65 (T1: Time…

Evidence exists for two competing theories about the effects of having an older sibling on development. Previous research has found that having an older sibling has both advantages and disadvantages for younger siblings' development. This study examined whether and how older siblings influenced the onset of their own younger siblings' motor…

Associations between reciprocal and complementary sibling interactions, sibling relationship quality, and children's socio-emotional problem solving were examined in 40 grade 5-6 children (M age = 11.5 years) from middle class, Caucasian, Canadian families using a multi-method approach (i.e. interviews, self-report questionnaires, daily diary…