What effects sign language has on the cognitive development of deaf children has been
discussed in two different directions. One is the perspective that sign language is an effec
tive tool of communication for deaf children. And the other is the perspective that the pe
culiar linguistic qualities of sign language help deaf children develop certain cognitive fun
ctioning. The theory of mind, a recently constructed approach to social cognition, provide
s a 'window' through which the two existing perspectives can be examined to better expla
in the relationship between sign language and cognitive development. In this paper, I expl
ored this relationship from the perspectives of the theory of mind. I also discussed what
suggestions the results of this research could make for the future education of deaf childr
en.