Abstract: This book offers a general theory of expressive behavior, including but not limited to such behavior as it occurs in our own species. At the core of the project is the thesis that self-expression is a matter of showing a cognitive, affective, or qualitative state in such a way that the showing is a product of design. Design may be the result of conscious intention, natural selection, artificial selection, or convention. Showing comes in three forms: showing that something is so, showing something in such a way as to make it perceptible, and showing how an object appears or how an experience or affect feels. This elucidation of self-expression as designed showing of something inner sheds light on such issues as the distinction between saying and showing, the nature of speaker meaning, speech acts, the problem of other minds, implicature, the psychology and evolutionary biology of facial expression, idiosyncratic and conventional aspects of expressive behavior, empathy, qualia, and artistic expression, particularly expression in music. The work blends insights from evolutionary game theory, ethology, experimental psychology, neuroscience, pragmatics, and the philosophies of mind and language.

Keywords: speaker meaning, speech acts, theory of mind, implicature, facial expression, empathy, qualia, artistic expression, musical expression, evolutionary game theory