This research examines the development of conceptual thought in infancy and early childhood, and the way these developments are reflected in early language. Until recently, we have had little information about the way infants conceptualize the world. It has traditionally been thought that infants first form concepts about concrete objects, such as dogs, chairs, and cars, and only later develop broader concepts of animals, furniture, and vehicles. However, research from our laboratory indicates that the broader concepts precede the more specific ones. Infants first form global and rather diffuse concepts, for example a general notion of how animate things differ from inanimate ones. With experience these gradually become differentiated into more adult-like concepts. In addition our tests of language comprehension indicate that a good deal of infant vocabulary refers to broader and more diffuse concepts than the meanings these words have for adults. This research uses several new techniques, involving the way that infants handle and explore objects. One of these techniques uses imitation to discover what preverbal children understand from events. We model events using little objects and then encourage the infants to imitate what they have seen. Infants and young children will only imitate what they understand, so by carefully varying the choices of objects available for them to use for their imitations, we can discover how they have construed the events that we model, even when they are too young to describe the events in words. The overall goal of the research is to provide a systematic body of knowledge about the preverbal foundations of thinking so that we can better understand what young children need to know in order to learn language. These studies are also important to provide an assessment of the level of young children's understanding of the world at the time they start preschool.
