Linguistic theory has recently experienced a shift in its conceptual approach from the formulation of descriptively adequate accounts of languages to the definition of principles and parameters claimed to reflect the initial structure of the language faculty, often termed Universal Grammar (UG). Linguistic experience is said to have the effect of guiding the child/linguist in fixing the unspecified parameters of U G to determine the grammar of his/her language. The study of anaphora has been of central concern as it addresses directly the innateness vs. experience issue. On the one hand, it is a part of all natural languages that is largely under determined by the data, and must therefore be included in the characterization of the initial state of the language faculty. On the other hand, although the principles that govern anaphora do not exhibit extreme variations across languages, a child/linguist must solve language specific issues for his/her language based on linguistic experience. This book examines a set of linguistic structures from both a theoretical and an experimental perspective. The purpose is to xv PREFACE xvi determine the roles of innateness and of experience in the devel opment of a child's theory of anaphora for his/her language.