Ingroup bias and the ‘black sheep’ effect: Assessing the impact of social identification and perceived variability on group judgements

Abstract

Two studies compared the relative strength of motivational assumptions drawn from SIT (e.g. Tajfel, 1978) and memory‐based assumptions drawn from the differential familiarity hypothesis (Linville, Fischer and Salovey, 1989) in explaining ingroup bias and the black sheep effect (Marques, 1986, 1990). In Study 1, 15 subjects estimated member distributions and gave overall ratings of an ingroup and two outgroups. In Study 2, 42 subjects performed similar tasks for ingroup or outgroup, and evaluated likeable and unlikeable group members. Results showed, first, that overall group ratings account better for ingroup bias than do central tendencies of group distributions. In addition, likeable and unlikeable ingroup members were, respectively, upgraded and downgraded relative to their outgroup counterparts. Finally, whole ingroup ratings as well as judgements of likeable and unlikeable ingroup members proved more independent from variability and central tendency of underlying distributions than did similar outgroup judgements. Results are discussed in light of motivational and knowledge‐based determinants of group judgements. Copyright © 1992 John Wiley & Sons, Ltd