網路新聞不文明留言普遍，人們如何處理與既存態度不一致的訊息、新聞討論區能否體現公共領域的研究仍相當有限。本文以引發爭議的同性婚姻合法化為背景，採用線上調查實驗，從偏見同化理論的角度，探討網路新聞不文明留言是否加深態度極化。結果發現與既存態度不一致的訊息是人們產生態度極化的主要原因，且不文明和文明留言均會產生偏見同化，兩者偏見同化的效果沒有顯著差異。

Incivility abounds in news comments today, but few studies have investigated how individuals process incongruent messages or have examined whether news comment sections are viewed as the public sphere. This study examined the effect of uncivil comments on attitude polarization using an online survey experiment based on bias assimilation theory to investigate the views of survey participants regarding the controversial issue of same-sex marriage legalization. The results found that incongruent messages trigger the primary mechanism of bias assimilation. However, the tone of the messages caused no significant difference on the bias assimilation effect, with the effect appearing for both uncivil and civil messages.