The purpose of this study was to examine the relationship between in-group favoritism and the "black sheep effect." In-group favoritism was measured by intergroup comparison of estimated rates of poor vs. excellent group members. Further, in-group favoritism was classified into three types. In the first experiment, we designed the in-group favoritism type as the independent variable, and the desirability of examples as the dependent variable. Those who perceived the ratio of in-group poor members to be smaller than that of the out-group (=in-group favoritism type focusing on poor members) showed the black sheep effeet. The second experiment examined the relationship between the black sheep effect and the ratio of poor members in the in-group favoritism type, focusing on poor members. We hypothesized that the black sheep effect might occur clearly when the ratio of poor members was small. The ratio of poor members was the independent variable, and the desirability score was the dependent variable. The results showed the effect of the ratio of poor members to be significant. These findings are discussed in terms of the implications for cognitive-motivational strategies related to the black sheep effect.
