IN-GROUP PROTOTYPICALITY AND PERSUASION - DETERMINANTS OF HEURISTIC AND SYSTEMATIC MESSAGE PROCESSING

Self-categorization theory (Turner, Hogg, Oakes, Reicher & Wetherell, 1987) proposes that identification with a social group will elicit a t endency to conform to in-group norms. Following this proposition, we a rgue that the extent to which persuasive ingroup communication is perc eived to reflect in-group norms, that is, is prototypical, will affect attitudes. Attitudes are predicted to be more affected by exposure to prototypical messages. Moreover, it is argued that prototypicality mi ght both instigate systematic message processing and function as a heu ristic cue. Whether systematic processing will occur was hypothesized to be dependent on the availability of cues enabling heuristic process ing. A study was designed in which subjects were exposed to a persuasi ve message from either a prototypical or an non-prototypical in-group source. In half of the conditions, subjects were informed about the op inion of the source before message exposure (which would enable heuris tic processing). Quality of the message (i.e. strong vs. weak argument s) and position advocated by the message were experimentally varied. I t was predicted that prototypicality would elicit conformity to in-gro up norms, but that it would only instigate systematic processing when subjects had no foreknowledge about the source opinion. Results suppor ted these predictions.