Above-and Below-Average Effects In Nonsocial Comparison

Above-and below-average effects widely appear in social and nonsocial comparison situations, influence comparisons'processes and results. Above-average effect is, showing the participants a group of congeneric items that is generally high on a specific dimension, but there're no significant differences between these items. Then the participants do the member-to-group comparisons, rate how a randomly selected member from the group compares with the rest of the group, the result shows the randomly selected item (target) tend to be rated as better than the remaining group. Below-average effect is contrary to above-average effect, the group of congeneric item is generally low on a specific dimension, and the randomly selected item tend to be rated as worse than the remaining group. There're less researches of the two effects in nonsocial comparison situation, Giladi and Klar, Windshitl, Conybeare & Krizan did some behavior researches, founded early and delayed donation processes and built LOGE approach and time account separately to explain the above- and below-average effects and their reverses. The time account indicated that the donation time of the target had significant influence to the effects'generation and reverse. In present study, we thought "compare with the compromise standard" caused the two effects, and the "abundant and non-abundant process time" influenced the effect through altering the participant's comparison strategies. In present research, we used non-abundant situation to investigate the mechanisms and differences of the two effects in two donation processes.Study 1 consolidated experiment processes and increased the amount of study materials based on previous researches to improve research's reliability and validity; used 3-point response scale to simplify the rating and used non-abundant situation to investigate the mechanisms and differences of the two effects in two donation processes. The result showed that either early or delayed donation process presented significant above- and below-average effects. The flexibility of participants'strategies probably caused the effects in early donation process, and in delayed donation process the effects probably caused by the design of the experiment process itself. The result clearly supported the LOGE approach, that was "compare with the compromise standard" caused the two effects. Based on Study l's paradigm, Study 2 used ERP methodology to investigate neural mechanism of the two effects in two donation processes. In early donation process, better judge in above-average effect and worse judge in below-average effect both demonstrated a more negative ERP deflection than the same judge during 700-1600 ms at the frontal lobe of brain, which probably reflected participants needed to retain and process more information when making judges. In delayed donation process, better judge in above-average effect demonstrated a more positive ERP deflection than the same judge during 570-620 ms at the right parietal lobe, which probably reflected that when recovering and processing the items that presented above-average effect, the participants needed to inhibit the activation of more unrelated information to ensure the working memory focus on the retain and process of the item's positive attribute. Worse judge in below-average effect demonstrated a more negative ERP deflection than the same judge during 800-1100 ms at the right parietal lobe, which probably reflected that to the items that presented below-average effect the participants needed to rehearse and retain more information to support judge.This research showed that, "compare with the compromise standard" caused the two effects. While under the non-abundant process time situation either early or delayed donation processes both presented above- and below-average effects, the mechanisms in two processes were different. Moreover, the generations of two effects had important relation with working memory, the delayed donation process had more activation at the parietal lobe than the early donation process, which probably reflected the participants needed to rehearse and retain more information when comparing and judging in delayed donation process.