Abstract: Abundant research has shown that language not only was related to, but also appeared to play a causal role in the development of theory of mind (ToM). However, it remained unclear which aspect of language development contributes most to the development of ToM. Some researchers such as Astington et al. (1999) and de Villiers (2002) had found that the syntactic (sentential complements) ability predicted unique variance in ToM task scores; others such as Lohmann and Tomasello (2003) focused on the significant contribution of both syntactic and semantic (mental verbs) abilities to the development of ToM. Still others such as Ruffman et al. (2003) emphasized the general verbal skills, rather than specific aspects of language development, in the development of ToM. The emphasis on general verbal skills is noteworthy given that the successful completion of ToM tasks requires understanding of contexts in which verbal communication occurs, in addition to adequate syntactic and semantic abilities. Therefore, using a short-term longitudinal design, we expected that preschoolers’ verbal skill test scores would significantly predict their ToM task scores six months later.
The participants were 80 four- and five year-old children recruited from a preschool in Ningxia. At both Time 1 (T1) and Time 2 (T2, six months later), trained research assistants administered three false belief tasks intended to assess ToM, and the Chinese version of McCarthy Scales of Children’s Abilities (MSCA)-Verbal Scale which measures children’s general verbal skills. Cross-lagged regression analysis was used to examine the prospective relation between children’s verbal skills and their ToM abilities.
Both the four- and five-years old children had higher verbal skill scores and ToM task scores at T2 than at T1. The results of cross-lagged regression analyses revealed a significant prospective relation between verbal skills at T1 and ToM abilities at T2 among four but not five years old children. These findings suggest that the increasing verbal skills among preschoolers may play a significant role in the development of ToM, yet the relation between verbal skills and ToM abilities appears to be stronger for younger children.
The results of this short-term longitudinal study provide some support for the important role of verbal skills plays in the development of ToM, particularly among four years old children. In addition, the finding that the prospective relation between verbal skills and ToM abilities was only found for four years old children suggests that the role verbal skills plays in the development of ToM may be a function of children’s age.

Key words: children, verbal skills, theory of mind, across-lagged-panel regression