One of the central problems in the study of modern cognition is the degree to which higher cognition is modularized: that is, how much are higher functions carried out by domain-specific, specialized, cognitive subsystems, rather than a highly general cognitive learning and inferring device? To date, ideas and proposals about modularity have been best developed in the study of vision and grammar. In the present volume, the usefulness of approaches employing modularity and domain specificity are further explored in papers on the development of biological thought, word meaning, symbols, and...