Abstract: One oft-cited feature of speech acts is their expressive character: Assertion expresses belief, apology regret, promise intention. Yet expression, or at least sincere expression, is as I argue a form of showing: A sincere expression shows whatever is the state that is the sincerity condition of the expressive act. How, then, can a speech act show a speaker's state of thought or feeling? To answer this question I consider three varieties of showing, and argue that only one of them is suited to help us answer our question. I also argue that concepts from the evolutionary biology of communication provide one source of insight into how speech acts enable one to show, and thereby express, a psychological state.