Abstract

Tools allow one to overcome the limits of one’s body in interacting with the environment. After learning to control their hands to grasp objects, babies gradually discover that one object can be used to act on other objects. In this article we shall discuss specifically the use of those tools that allow far-off objects to be brought into range. We shall first describe studies of behaviours that are precursors to this skill, in particular means-end behaviours that require invoking an intermediate means to attain a final end. We shall then describe the existing studies of the use of a tool to bring an object closer. In the second part of the article we ask what the mechanisms are that might underlie the discovery of this kind of tool use. We shall appeal to results of a study in which we followed four infants starting at age 12 months for about a year, and in which they had to attain an out-of-reach toy with a rake. Our results show that the infants needed several months before understanding the use of the rake. During this period they explored the rake, begged for the toy, played with toy and rake together but without trying to bring the toy closer. Only around age 18 months did the infants, somewhat suddenly, come to understand that the rake could be used to attain the toy. We conclude that in order to be helpful, trial and error, as well as observational learning, require the child to have a degree of intuition concerning the solution. This intuition itself requires a long period of exploration which may contribute both to improving the child’s ability to manipulate the rake (perhaps becoming an extension of the hand) and to improving the child’s knowledge of the rake’s affordances.

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