Margaret Anne Defeyter

Acquiring an understanding of design: evidence from children's insight problem solving.

The human ability to make tools and use them to solve problems may not be zoologically unique, but it is certainly extraordinary. Yet little is known about the conceptual machinery that makes humans so competent at making and using tools. Do adults and children have concepts specialized for understanding human-made artifacts? If so, are these concepts deployed in attempts to solve novel problems? Here we present new data, derived from problem-solving experiments, which support the following. (i) The structure of the childs concept of artifact function changes profoundly between ages 5 and 7. At age 5, the childs conceptual machinery defines the function of an artifact as any goal a user might have; by age 7, its function is defined by the artifacts typical or intended use. (ii) This conceptual shift has a striking effect on problem-solving performance, i.e. the childs concept of artifact function appears to be deployed in problem solving. (iii) This effect on problem solving is not caused by differences in the amount of knowledge that children have about the typical use of a particular tool; it is mediated by the structure of the childs artifact concept (which organizes and deploys the childs knowledge). In two studies, children between 5 and 7 years of age were matched for their knowledge of what a particular artifact is for, and then given a problem that can only be solved if that tool is used for an atypical purpose. All children performed well in a baseline condition. But when they were primed by a demonstration of the artifacts typical function, 5-year-old children solved the problem much faster than 6-7-year-old children. Because all children knew what the tools were for, differences in knowledge alone cannot explain the results. We argue that the older children were slower to solve the problem when the typical function was primed because (i) their artifact concept plays a role in problem solving, and (ii) intended purpose is central to their concept of artifact function, but not to that of the younger children.

Immunity to functional fixedness in young children

In thecandle problem (Duncker, 1945), subjects must attach a candle to a vertical surface, using only a box of tacks and a book of matches. Subjects exhibitfunctional fixedness by failing, or being slow, to make use of one object (the tack box) as a support, rather than as a container, in their solutions. This failure to produce alternate functions is measured against improved performance when the tack box is presented empty rather than full of tacks (i.e., not preutilized as a container). Using an analogous task, we show that functional fixedness can be demonstrated in older children (6- and 7-year-olds); they are significantly slower to use a box as a support when its containment function has been demonstrated than when it has not. However, younger children (5-year-olds) are immune to this effect, showing no advantage when the standard function is not demonstrated. Moreover, their performance under conditions of preutilization is better than that of both older groups. These results are interpreted in terms of children’s developing intuitions about function and the effects of past experience on problem solving.