Introduction

Young children find desires easier to understand than beliefs and may understand desires with little or no understanding of beliefs. In this chapter, I review evidence and explanations for that lag. I conclude by offering a novel explanation, arguing that children's conception of other people undergoes an important shift when they begin to engage in conversation. Initially young children conceive of other people primarily as agents with goals, but around three years of age they start to construe people as epistemic subjects capable of exchanging information for the formation and updating of beliefs. Hence, they shift from a desire psychology to a belief-desire psychology.

Evidence for the lag

Evidence for the lag between desire and belief understanding has emerged from research with autistic as well as normal children. Autistic children are poor at understanding false beliefs (Baron-Cohen, 1991b; Baron-Cohen, Leslie, and Frith, 1985; Leslie and Frith, 1988), especially second-order beliefs (i.e., beliefs about beliefs) (Ozonoff, Pennington, and Rogers, 1991a). There is no published evidence of an equivalent impairment in their understanding of desires. They can remember and re-assert a previously-stated desire (Tan and Harris, 1991). Although they rarely talk about thoughts and beliefs, they do talk about desires (Tager-Flusberg, 1992; 1993).