Framing Effect. How Metaphors Frame the World - In the study of metaphor, frame is intended as the context, the environment, the landscape in which a metaphor is conceived, expressed and used; the term framing was introduced by George Lakoff within a cognitive setting and gives a distinctive shape to his theory. The idea however can be traced back to Richards (1936) and Black (1962): both the tenor vs. vehicle and the topic vs. focus distinctions, on the ba- sis of which they propose a general characterization of a metaphorical domain, can be considered as instances of framing in the sense argued by Lakoff. The same holds for recent cognitive theories of metaphor such as Way’s (1991) and Indurkhya (1992). Interestingly, the notion of frame has been invoked by well known psychologists like Kahneman and Tversky as a fundamental conceptual model for explaining human rational behaviour and decision making. In this paper we maintain that the psychological approach is not indifferent to the frame theory of metaphor. On the contrary, it offers useful clues and research hypotheses for further development. Keywords: Context, Decision, Focus, Frame, Metaphor, Rationality.