Five studies examined the relations between attitude importance and 3 of its hypothesized determinants: self-interest, social identification with reference groups or reference individuals, and cherished values. Verbal protocols, multivariate analysis of survey data, and laboratory experimentation revealed that (1) people's theories of the causes of attitude importance pointed to all 3 hypothesized predictors, (2) the 3 predictors each had significant, unique statistical associations with importance, and (3) a manipulation of self-interest yielded a corresponding change in importance. These results help clarify the nature and origins of attitude importance, challenge the widely believed claim that self-interest has little or no impact on political cognition, and identify new likely consequences of social identification processes and values.
