Attitude-behaviour relations: the role of in-group norms and mode of behavioural decision-making.

Two experiments provided support for the central hypothesis--derived from social identity/self-categorization theories--that attitudes would be most likely to predict behaviour when they were supported by a congruent in-group norm. In the first experiment, norm congruency and mode of behavioural decision-making (spontaneous or deliberative) were orthogonally manipulated in a between-subjects study of career choice in psychology. Participants exposed to an attitudinally congruent in-group norm towards their preferred career choice were more likely to display attitude-behaviour consistency than those exposed to an attitudinally inconsistent group norm, an effect that was evident under both spontaneous and deliberative decision-making conditions. Using a mock jury paradigm, Expt 2 replicated and extended the first experiment by including a manipulation of in-group salience. As predicted, participants exposed to an incongruent norm displayed greater attitude-behaviour inconsistency than those exposed to a congruent norm. Contrary to predictions, this effect did not vary as a function of group salience, nor did the effects of group norms for high and low salience participants vary as a function of mode of behavioural decision-making. However, there was evidence that perceived identification with the group moderated the influence of norms on attitude-behaviour consistency.