Letter labels and illusory correlation: infrequent letters bias reactions to the group.

A previously underappreciated factor, the specific letters used to label the groups, was found to influence the magnitude of the well-established illusory correlation (IC) effect . The typical IC effect of an association between the minority group and the rarer (negative) behavior was strong when the minority group was labeled with an infrequent letter (e.g. X, Z) and the majority group was labeled with a frequent letter (e.g. S, T), but the effect was eliminated (or reduced) with the reverse pairing of the majority group with an infrequent letter. The letter label effect was also found with the A and B labels most commonly used in this paradigm. The results were consistent with an explanation based on the affect associated with the letters due to the mere exposure effect. The findings reveal a previously unexplored way that the names for groups may influence stereotype formation, contribute to the debate on the mechanism underlying IC, and illustrate how arbitrarily chosen labels for groups and other objects in social research may bias processing in unexpected ways.