New Tool, New Function? Toddlers' Use of Mutual Exclusivity When Mapping Information to Objects


  • The author is indebted to several anonymous reviewers for valuable comments on an earlier draft of this paper. Special thanks also go to Elizabeth Hackett and Kerry Whiteman for assistance in data collection and to the staff and families at College Hill Children's Center, Grace Place Children's Center, and Elizabethtown Child Care Center.


Prior research has suggested that 24-month-old toddlers will rapidly map the function of a novel object but that, unlike preschoolers and adults, they will use the tool for other purposes as well. Here, this nonexclusive pattern of object use was explored. Because it has been unclear whether a mature “one tool, one function” bias in assigning object functions is rooted in deployment of general learning principles or artifact-specific thinking, Study 1 explored 24-month-olds' exploitation of social-pragmatic cues when mapping labels, facts, and functions to novel objects. Results demonstrated that toddlers readily used a principle of mutual exclusivity to constrain assignments of labels and facts but not functions. This performance was corroborated in Study 2. It appears that 24-month-olds have a developing understanding that artifacts have specialized functions but that mutual exclusivity does not guide this development.