ABSTRACT
Since the early 1980s, the acquisition of a theory of mind, defined as the ability to predict and explain people's behavior with reference to mental states, has been seen as a crucial watershed in social-cognitive development: one that changes the toddler from a literal observer of human behavior to a folk psychologist, capable of making complex mental-state attributions, engaging in elaborate social and communicative games, and even deception. Theory of mind ability, variously referred to as mentalizing, mind reading, or belief-desire psychology, has traditionally been viewed as the foundation for our adultlike understanding of the social world. As Wellman (1990) expressed it:
Why is achievement of a theory of mind important?…belief-desire psychology is our framework theory of persons. As a framework theory it dictates our basic ontology, our parsing of personal action and thought into its most basic categories. And it dictates our causal-explanatory infrastructure, our basic grasp of how to go about making sense of ourselves and others. In short, belief-desire psychology frames our worldview.
(p. 328)