The underlying process of reactions to social identity threat was examined from a defense motivation perspective. Two studies measured respondents’ social identification, after which they read threatening group information. Study 1 compared positive and negative group information, attributed to an ingroup or outgroup source. Study 2 compared negative and neutral group information to general negative information. It was expected that negative group information would induce defense motivation, which reveals itself in biased information processing and in turn affects the evaluation of the information. High identifiers should pay more attention to, have higher threat perceptions of, more defensive thoughts of, and more negative evaluations of negative group information than positive or neutral group information. Findings generally supported these predictions.