A theoretical position that mind is not separate from the ways in which it is evidenced through the body is in contrast with an assumption made in the literature on children's theory of mind that maintains that mental states can only be demonstrated independently of their behavioral context. This assumption is tested by the false belief criterion, which supposedly studies mental motives, and which closely resembles some of Piaget's tests of object permanence. In an effort to test infants' understanding of others' minds, a series of studies of babies' comprehension and production of referential behaviors was carried out. Results suggested that three mechanisms underlie mothers' and infants' joint visual attention. The ecological mechanism involves the infant's ability to understand the mother's orienting behaviors; the geometric mechanism involves the infant's ability to pick out the direction and location of an object referred to by the mother; and the representational mechanism, which is evident after 18 months of age, involves infants' attempts to look in hidden locations. These results suggested that mechanisms of attention and perception in infancy presuppose object permanence. A list of 12 references is provided. (BC)