Mood and the impact of category membership and individuating information

We investigated how individuals in different mood states are influenced by category membership information, by individuating information, and by the relation of the two in an impression formation task. Subjects in different mood states received positive or negative individuating information and positive or negative category information about a target person. Experiment 1 indicates that sad subjects were influenced by individuating but not by category membership information. In contrast, happy subjects' judgments reflected the implications of the category information as long as the individuating information was not inconsistent with the category, replicating previous research. This pattern was eliminated, however, when category-inconsistent information was provided, suggesting that happy subjects related the individuating information to the category membership information. Additional experiments show that instructing neutral mood subjects to relate category and individuating information or to focus on the individuating information result in patterns that parallel the judgments of happy and sad subjects, respectively, and that these effects are only obtained when the category information precedes (rather than follows) the individuating information. Extending previous theorizing, we conclude that being in a happy mood increases the likelihood that information is processed in the light of pre-existing general knowledge structures.