This thesis studies the effects of the conformity motive and temptation on individual decision-making. Social dissonance is the discomfort of choosing an action different from what others have chosen. A game-theoretical framework is used to study situations where social dissonance influences behavior or expression of opinions. Each individual may have different intrinsic preferences but is affected by the same ``institution" which is modeled by a social dissonance function that evaluates the negative effect of disagreement with others. Equilibria of social dissonance games have properties such as monotonicity of choices with respect to intrinsic preferences, and monotone comparative statics with respect to changes in intrinsic preferences and institutions. ``Impulse and Temptation" acknowledges that consumers who purchase larger packages of certain goods are tempted to consume more than originally needed. The analysis attempts to understand policies that prohibit the purchase of smaller packages, exploring issues of consumer naivete about temptation and addiction. It makes little sense to restrict access to small packages in a one-period model with or without consumer naivete, but it is possible that in a multi-period setting, defense against addiction is a valid reason for prohibiting sale of small packages of tempting goods.