第三人效果：社會向下比較過程的自利偏差

The Third-Person Effect: Self-serving Bias in the Processes of Downward Social Comparisons

本研究以684位台灣年輕選民對2012年總統大選競選相關訊息影響力的評估，探討第三人效果認知差距形成的過程，並檢測第三人效果認知差距對選民行為造成的影響。社會心理學相關研究結果建議，人我之間媒體效果差距評估的形成，是在自利偏差的趨使下經由社會比較過程之結果。在此社會比較過程中，訊息評估者會以最易受影響者為評估基準點，並依訊息內容的需求性進行向上或向下比較，以滿足自我提昇的心理需求。本研究結果驗證此社會比較過程的存在：台灣大學生選民傾向以最易受選舉訊息影響的中立選民為競選相關訊息影響力的比較基準點，進行向下社會比較而形成第三人效果認知差距，且此認知差距愈大，愈會增強選民在未來總統大選期間要求媒體自律之意願。

This study provides a theoretical explanation for third-person perceptual differentials and investigates how the perceived discrepancy between the impact of presidential election messages on the individual and on other people influenced voter support for media restriction in the context of the Taiwanese Presidential Election in 2012. This study proposes that the mechanism underlying the third-person perceptual disparity is a downward social comparison process that occurs when the perceivers, driven by self-enhancement bias, use the most vulnerable segments of society as the comparison anchor to form judgments of media effects on themselves and other people. An analysis of the responses from 684 voters in the 2012 Taiwan Presidential Election supports this assumption. The results showed that respondents used independent voters as comparison anchors to minimize the influence of election messages on themselves, which resulted in differences in media vulnerability among the comparison groups. In addition, a greater third-person perception was found to be associated with stronger support by voters for media self-regulation during future presidential elections.