Norms of Assertion: A Perspective from Evolutionary Game Theory 1 Mitchell Green University of Virginia contents: 1. Speech acts, acts of speech, speaker-meaning, and communication 2. Assertion and its cousins 3. Detecting intentions and extending the neck 4. Cues, signals and handicaps 5. Credibility 6. Sven and Elke over breakfast 7. Illocutionary skepticism Many philosophers take it as a platitude that speech acts are governed by norms, but do not often attempt to formulate this idea with any precision, or to be very clear about its justification. In this essay I shall attempt to justify the idea that speech acts are governed by norms, and in the process to formulate the idea with a reasonable degree of clarity. To do this I’ll have to disentangle a number of these concerning the relation of speech acts and norms. My main conclusion will be this: If there are speech acts in the technical sense of that expression, then they are governed by constitutive norms; however, this does not imply, and it is not true, that all speech acts crucially involve conventions. 1. Speech acts, acts of speech, speaker-meaning and communication: First some preliminaries in order to forestall confusion. Let’s remember first of all that ‘speech act’ is a term of art. To see why, observe first of all that speech acts are not to be confused with acts of speech. One can perform a speech act such as issuing a warning without saying anything: A gesture or even a minatory facial expression will do the trick. So too, one can perform an act of speech, say by uttering words in order to test a microphone, without performing a speech 1 Presented at the 10 th International Pragmatics Conference, Goteborg, Sweden, July 12, 2007.