Are there different pathways to explicit false belief understanding? General language and complementation in typical and atypical children

- We evaluated the role of language in children's false belief understanding.
- We specifically compared the impact of complementation versus general language in typically and atypically developing children.
- Complementation was inconsistently related to FBU in the typically developing chidren.
- Complementation was more critical to the atypical groups, particularly children with autism.
- Different populations may have different linguistic pathways to false belief understanding.

Though converging empirical evidence strongly supports the role of language in explicit false belief understanding (FBU), there is a lack of consensus on the theoretical basis of this link. This debate has centered on whether complement syntax is required for FBU or whether general language skills are sufficient. Although hundreds of investigations have confirmed the role of language in FBU, the precise role of complementation and general language remains unclear. In the present review, we selectively examine through both meta-analysis and qualitative analysis, only studies that utilize both complementation and general language measures in typically and atypically developing children (e.g., children with autism). These analyses supported the general language hypothesis, but not the complementation hypothesis in typically developing children. In contrast, the complementation hypothesis was supported in the children with autism, as well (children with deafness and SLI). Together, these results suggests there are different linguistic pathways for developing FBU in typical and atypical children. These alternate routes may be attributable to differences in children's ability to benefit from social interactions in acquiring FBU. Finally, we discuss suggestions for future research including methodological choices in research design, language assessments, and populations.