Understanding Cultural Norms via evolutionary game theory: A new approach Don Saari University of California, Irvine (UCI) Director, Institute for Mathematical Behavioral Sciences It is reasonably accepted that several cultural and social norms evolve over time due to multiscale interactions of acceptance and dismissal--examples are given. But, how can this be modeled? This is a conference for a mathematics institute, so it will be shown how one possibility is to use evolutionary game theory (all terms will be introduced during the presentation). The approach developed here is new; it avoids many of the usual mathematical complexities and requires data to become part of the modeling.