Sibling conflict and theory of mind

This study examined conflicts between siblings in an attempt to identify variables that are related to false‐belief understanding. The variables investigated were children's use of mental state terms and specific types of arguments (Slomkowski & Dunn, 1992) that occurred during conflict episodes. Twenty‐two children between 3 and 5 years of age were administered eight false‐belief tasks and were also videotaped while playing with an older sibling. Use of other‐oriented arguments by the target child was significantly associated with success on false‐belief tasks after controlling for age and general language ability. No use of argument was negatively related to performance on the false‐belief tasks after controlling for age and general language ability. Neither the use of self‐oriented arguments nor use of mental state terms was found to be associated with false‐belief performance. The findings indicate that specific features of sibling conflicts are related to children's developing false‐belief understanding.