The first goal of this paper is to review the evidence in support of the claim that markedness and topic continuity are funtionally related. Both linguistic and psychological evidence are included in this review. The linguistic evidence comes from both traditional linguistic argumentation (based on examples and appeals to the reader's intuition) and from a collection of cross-linguistic, normative studies reported in Givon (1983a). The psychological evidence includes recent studies of pronoun resolution and a direct test by Fletcher (1984). The second goal of this paper is to describe some of the implications of this functional relationship and the research that has uncovered it. These include implications both for the nature of language and for the manner in which it should be studied.