The emergence of a tool-using skill in infancy.

The use of a spoon for eating is one of the first tool-using skills acquired by most infants. The article provides a description and analysis of how the skill is built during the second year of life. A number of behavior categories were identified and measures were developed from a pilot study on a group of infants aged 10-58 months. Two groups of infants, aged 11 and 17 months, respectively, when the study began, were observed at monthly intervals over a 6-month period. Videotapes of mealtimes were subjected to detailed analysis that included extracting data on the following: hand use, grip pattern, visual monitoring, movements involved in the action, activities of the contralateral hand, spoon trajectory, temporal structure of the action, and so on. The emergence of competence was examined through comparisons within and between the groups. The acquisition of a tool-using skill is discussed in terms of the emergence of strategies to solve particular problems and the increasing consistency and reliability with which these are deployed. The term skill refers to expertness, to a facility in doing something. Skills are practiced abilities that show deftness, dexterity, and confidence in performance; they are goal-directed actions. The essential features of skill become apparent through a few examples. Consider a craftsman or craftswoman at the workbench using tools to fashion an object, a person engaged in a ball game such as tennis, a surgeon performing an operation, and you the reader eating your dinner with the customary cutlery. A property common to each of these situations is that the person performing the action has to match the demands of the task to his or her capacities, and this is done by applying a method, as often as not called a strategy, of performance. For example, the craftsman or craftswoman shaping wood into a particular form does so by manipulating tools that he or she has selected for the purpose. Through the tools the operator exerts forces and by so doing forms the object. Tennis, surgery, and dining are in certain important respects similar to each other, and in common with all skills they entail both knowing what and knowing how. The strategies that a performer employs are not usually concerned with single responses to stimuli but with programs of action that project forward from the situation in which they are initiated to a future goal. In his insightful analysis of skill, Bartlett (1958) pointed out that there is a continuous flow of signals, which arise outside the performer and which are interpreted into actions. These actions in turn lead to further signals and so to further action. Skill thus implies a transaction between the performer and the environment, and to understand skilled performance it is necessary to understand the nature of the organism-environment interaction with regard to the specific context and the goal in question. Skills are always jointly determined by the organism, the task, and the precise environment in which the actions take place. The environment supports the action. This implies that