In the literature of psychology and economics it is frequently observed that individuals tend to conform in their behavior to the behavior of similar individuals. A fundamental question is whether the outcome of such behavior can be consistent with self-interest. We propose that this consistency requires the existence of a Nash or approximate Nash equilibrium that induces a partition of the player set into relatively few societies, each consisting of similar individuals playing the same or similar strategies. In this paper we introduce a notion of a society and characterize a family of games admitting the existence of such an equilibrium. We also introduce the concept of `crowding types' into our description of players and distinguish between the crowding type of a player -- those characteristics of a player that have direct effects on others -- and his tastes, taken to directly affect only that player. With the assumptions of `within crowding type anonymity' and `linearity of taste-types' we show that the number of groups can be uniformly bounded.
