 We can here give only a broad overview of an enormous and complicated literature. Readers are referred to critical surveys in  Kagel and Roth (1995),  Camerer (2003),  Samuelson (2005),  and  Guala (2005).  A useful high-level principle for sorting the literature indexes it to the different auxiliary assumptions with which game-theoretic axioms are applied. It is often said in popular presentations (e.g.,  Ormerod 1994)  that the experimental data generally refute the hypothesis that people are rational economic agents. Such claims are too imprecise to be sustainable interpretations of the results. All data are consistent with the view that people are approximate economic agents, at least for stretches of time long enough to permit game-theoretic analysis of particular scenarios, in the minimal sense that their behavior can be modeled compatibly with Revealed Preference Theory (see  Section 2.1).  However, RPT makes so little in the way of empirical demands that this is not nearly as surprising as many non-economists suppose  (Ross 2005a).  What is really at issue in many of the debates around the general interpretation of experimental evidence is the extent to which people are maximizers of expected utility. As we saw in  Section 3,  expected utility theory (EUT) is generally applied in tandem with game theory in order to model situations involving uncertainty — which is to say, most situations of interest in behavioral science. However, a variety of alternative structural models of utility lend themselves to Von Neumann-Morgenstern cardinalization of preferences and are definable in terms of subsets of the  Savage (1954)  axioms of subjective utility. The empirical usefulness of game theory would be called into question only if we thought that people’s behavior is not generally describable by means of cardinal vNMufs.