Abstract

The present study was designed to identify the source of evaluation bias. Focusing on the difference between distribution bias and evaluation bias may reveal different mechanisms involved. Experiment 1 was designed to see whether evaluation bias occers in the minimal group situation, and to determine the factors responsible for appearance of an evaluation bias in minimal group situation, Tajfel et al(1971)'s experimental situation. The result showed relative evaluation of product played a major role in producing an evaluation bias in the minimal group situation. To evaluate the importance of relative vs. absolute evaluation of product in producing an evaluation bias in the minimal group paradigm, two evaluation methods and two evaluation objectives(production or distribution) were combined in Experiment 2. Results confirmed the findings of Experiment 1. Relative evaluation of product was a critical factor affecting production bias. Experiment 3. examined the factors affecting evaluation bias in the competitive situation. The winning group showed a significant evaluation bias in the competitive situation, but the losing group did not show ingroup bias regardless of the evaluation method used.