It is well known that certain properties of reflexives, such as binding domain and choice of antecedent, vary both between and within languages (Burzio, 1989, 1991; Everaert, 1991; Katada, 1991; Koster, 1987; Reinhart & Reuland, 1991; Yang, 1983, among others). In this chapter I argue that these differences result from the interaction between the feature composition of the reflexive morphemes, their status with regard to X' theory, and general principles of Universal Grammar as formulated in Chomsky (1981, 1986, 1989, 1992). Such an account predicts that the acquisition of the core properties of reflexives should be almost instantaneous: Under the hypothesis that the child is constrained by Universal Grammar, acquisition will happen as soon as the child fixes the morphological properties of these expressions, on the basis of linguistic data. These claims are substantiated by contrasting syntactic and acquisition facts from French and Danish, a Romance and a Mainland Scandinavian language, respectively. The analysis of these facts supports the definition of governing category as formulated by Chomsky (1986): "A governing category of a is a maximal projection containing both a subject and a lexical category governing a (hence, containing α). A governing category is a 'complete functional complex' (CFC) in the sense that all grammatical functions compatible with its head are realized in it" (p. 169). The behavior of the reflexives is shown to comply with Principle A of the Binding Theory, as proposed by Chomsky (1981): An anaphor is bound in its governing category. Arguments are presented in favor of the hypothesis that the core case of binding is local binding and that long-distance binding results from a last-resort operation, triggered by morphological necessity.