<p dir="ltr">Appealing to individuals’ social identity is a powerful form of social influence, capable of changing the way people process information, the information they think about, and how they evaluate other people. This form of social influence can function through perceptions of normal behavior within a social group, in which members of a group interpret ambiguous information through the lens of what is considered to be normal in their ingroup. The Social Identity Decision Process hypothesis, based on Social Identity Theory and Probabilistic Persuasion Theory, suggests that group norms associated with a decider's social identity can alter the perceived importance of attributes or cues in a decision environment and the strategies that are used to make choices in situations in which the group identity is salient. Taking the U.S. political landscape as a context and examining Republican and Democrat social identities, norms from these political groups were expected to impact the attributes and strategies partisans use when choosing whether to have solar panels on a house. Two studies are reported that examined these effects through multi-attribute decision making, in which predefined decision process models assessed participant behavior to analyze which attributes best describe participants’ decision making.</p>