European journal of social psychology vol:26 issue:1 pages:75-96
The present study attempted to determine whether the impact of overlapping categorizations upon intergroup differentiation should be attributed to cognitive category differentiation processes or whether motivational social identity processes do also intervene. Experimentally created groups were placed in one of four overlapping categorization conditions: the overlapping category was either absent or it was affectively positive, negative, or neutral. These groups were also differentially evaluated by providing them with positive, negative, or no feedback. Subjects estimated then the performance of the two groups in an experimental task. Thereupon, their self-esteem and their liking of the groups were also measured The presence of an overlapping category had no impact upon the performance evaluations of positively evaluated groups. Negatively evaluated groups favoured the outgroup but the presence of an overlapping category led also to a reduction of this perceived ingroup inferiority. The groups of the no-feedback condition exhibited ingroup favouritism. The presence of a positive and of a neutral overlapping category reduced this bins but the presence of a negatively evaluated overlapping category strongly enhanced it. The impact of overlapping categories upon the liking measure was less pronounced. Group members' self-esteem was influenced by the experimentally manipulated factors, but these effects did not really support social identity theory. The theoretical implications of the data are discussed.