ABSTRACT
The several chapters in this volume have established a convincing case for the presence of modules of specialized—and possibly segmented—areas of knowledge and skill. I wish to start from the assumption that modules or constraints exist, and to ask: What follows? The specific three questions I raise have to do with (a) criteria for the inference of separate or dissimilar areas of knowledge or performance; (b) the nature of relations or connections among segmented areas; and (c) the implications of a concept of modules, constraints, or segments for developmental theory in general.
