Kurt W. Fischer Thomas Bidell Harvard University
Biological factors clearly play a major role in cognitive development, setting constraints on behavior that provide directions to development. As Peter Marler (this volume) has argued persuasively, even the capacity to learn is itself a species-specific characteristic, determined in part by genetic inheritance. For too long, researchers in cognitive development have merely assumed that such constraints are at work and avoided the difficult business of ferreting out the specific nature of the genetic constraints and their relation to the development of cognitive skills. This gap is now beginning to be closed, thanks largely to a newly emerging research tradition variously referred to as structural-constraint theory, rational constructivism, or neo-nativism.
The purpose of this chapter is to offer a critical appraisal of some of the theoretical claims and research methods of this new tradition. We believe that the study of biological constraints on cognitive development is a timely and important new trend in the field; yet in any new approach there is always a risk that new discoveries will be overgeneralized. New, and sometimes startling, information about infants' and children's seemingly precocious skills promises to illuminate the relations between biological constraints and cognitive development. At the same time, inferences about innate knowledge or concepts have been drawn that are overgeneralizations not warranted by the evidence. To avoid such overgeneralizations, we suggest theoretical and methodological guidelines for constraining these inferences, placing the evidence within an epigenetic framework that both emphasizes the importance of the early behaviors and specifies their limitations.