Testing four explanations for the better/worse-than-average effect: Single- and multi-item entities as comparison targets and referents
In six experiments, we tested four explanations for the better/worse-than-average effect (B/WTA) by manipulating the number of items comprising the target or referent of direct comparison. A single-item target tended to be rated more extremely than a single-item or a multi-item referent (Experiments 1–3). No B/WTA was obtained, however, when a multi-item target was compared with either a single- or multi-item referent (Experiments 4 and 5). A bias favoring a multi-item target was found only if cohesiveness among the items was increased through instructions (Experiment 6). The Unique-Attributes Hypothesis generally provided the best explanation the findings; the focalism explanation also demonstrated some empirical viability. The results suggest that important preferential decision-making outcomes can be affected by both the number of items and whether items are strategically manipulated to serve as targets or referents of comparison.
Suls, J., Chambers, J., Krizan, Z., Mortenson, C. R., Koestner, B., & Bruchmann, K. (2010). Testing four explanations for the better/worse-than-average effect: Single- and multi-item entities as comparison targets and referents. Organizational Behavior and Human Decision Processes, 113,1, 62-72