When Can Every Group Member be Above the Group's Average? The Weighted LOGE Theory of Social Comparison Biases
Authors: Etgar Shir 
Published: July 2020

The Non Selective Superiority bias (NSSB) is defined as the tendency to judge each randomly chosen group member from a positive group as better than the other group members from the same group. While this is a reliable and robust bias, its origins are still debated. Internal explanations of the bias posit that NSSB is caused by some distortion in the internal comparisons between the focal group member and the other members of the same group. According to unique attribute theory (Chambers, 2010), NSSB occurs because each individual group member of a positive group is judged according to the dimension that positively distinguishes this individual member from the other members of the same positive group. According to focalism theories (e.g., Moore &amp; Kim, 2003; Posavacet al., 2004), judges focus excessively on the standing of the focal member on the judged quality rather than the corresponding status of the others in the group on the same quality (i.e., "this candidate is highly curious" rather than "this candidate is curious more than other candidates in the short list").Giladi and Klar (2002) proposed an external explanation for the bias, meaning, suggested that the bias occurs due to a distortion that is not related to a comparison between the focal group members. Their approach, LOGE (Local comparisons- General Standards), suggested that in addition to the internal comparison between the judged group member and the others in the local group, a second, simultaneous comparison also takes place. This is a comparison between each judged group member and the general standard, which represents the judge's knowledge and experience about the range of qualities within the larger category that pertains to the judged local group. This external standard is logically irrelevant to the comparison process; however, cognitively, it cannot be avoided. According to LOGE, NSSB is due to the intrusive effect of the external comparison with the general stand pertaining to the judged quality. The original LOGE theory paid no special attention to the relative judgmental weights of the two components (i.e., internal and external; DIFFL and DIFFG) in the resulting comparative judgment. Therefore, it was impossible to draw experimental predictions from the original theory. This dissertation attempts to rectify this issue. This work proposed a better specified version of LOGE which is termed Weighted-LOGE (W-LOGE). In this version, the relative weights of DIFFL and DIFFG can vary. This enables me to test the main LOGE prediction: the greater the judgmental focus is ascribed to DIFFG (rather than to DIFFL), the greater the comparative bias should be. This prediction suggests that when the focus is on the internal commonalities (rather than differences) within the local group, judges are likely to be less preoccupied with within-group comparisons (i.e., DIFFL) and consequently, will be engaged to a greater extent in the external comparison (i.e., DIFFG). W-LOGE will predict that in this case, a greater NSSB will occur. In the first empirical section, we compared this prediction to unique attribute theory's predictions, Across three studies, we found support to the W-LOGE predictions, suggesting that NSSB increasing when group members are similar to each other. The next empirical section compared between W-LOGE and Focalism. This section employed a sequential comparative judgment method, in which each group member was judged in turn against the others in the group. Focalism approaches argued that the origin of NSSB is the neglect of the non-focal group members during the comparative judgment. Therefore, when the focal member role alternates in each comparative judgment from one group member to another, Focalism assume that NSSB should progressively diminish or even totally disappear. Here as well, across three studies, evidence supported W-LOGE theory.In the final experimental section of this work, the sequential method used to directly contrast W-LOGE with both Focalism and unique attribute approaches. If judges repeatedly consider how superior each local group member is compared to the general standard, as seen at the previous section, what will happen when they additionally focus on within-group similarities? W-LOGE predicts that when the focus is on within-group similarities, the pluses of each of the local group members versus the general standards might even bolster the judgments and thus NSSB could even gradually increase with successive judgments. Across three additional study, this prediction was supported. Across these nine studies, which utilized the W-LOGE model, I found support to the experimental predictions draw from the LOGE theory. These studies corroborate the claim that the logically irrelevant comparison of judged group members with an irrelevant general standard is the main cause of NSSB, since the relative judgmental weight assigned to this external comparison regulates the magnitude of the bias.