社交媒体平台，作为现代信息传播的关键媒介，其在健康信息交流领域的重要性日益凸显。然而，平台的开放性和多元性特征，也使其成为争议性健康信息的集聚地。科学家对于此类信息的态度和观点尚未形成共识，由此产生了对立的学术观点。在社交媒体平台中，这些对立观点常被片面地引用与解读，进一步加剧了健康争议的二元对立态势。因此，围绕争议性健康话题的讨论往往呈现出群体极化的趋势。

为探究在线争议性健康话题中群体极化的演化趋势与成因，本研究选取“中医争议”作为典型案例，收集了2019年9月到2020年5月之间网易新闻平台发布的有关“中医、中药”等所有新闻以及有关的评论。本研究采用计算传播研究方法，基于社会认同的理论基础，对群体极化的影响因素进行了深入探讨。

研究发现，随着讨论的加深，群体极化的程度在总体上呈现出显著加剧的趋势。具体而言，比起同质性的信息环境，群体接触到相悖的观点更能推动群体走向极化。这一趋势在那些支持中医的群体中尤为显著。这一发现挑战了传统观点——个体走出回音室，接触到不一样的观点能减轻极化。然而本研究发现，群体接触到对立信息，只会在各自的“壕沟”中坚守立场，并通过辩论和反驳来与对方“交火”，而不是寻求真正的对话和理解，从而形成了“壕沟战”效应。

为进一步探索这一效应的成因，本研究采用批评话语分析方法。研究发现，中医支持派和反对派之间并没有试图采用理性行为说服对立群体。他们主要使用贴标签、人身攻击等行为排斥外群体，构建二元对立关系，试图将双方与个人主义和非理性行为联系起来，并在民族主义的情感动员下，将中医问题视为国家立场问题，导致了中医争议更加两极分化。

本研究通过深入分析争议性健康话题中群体极化的影响机制，揭示了其背后的实质和动因。这一探索不仅有助于研究者更加深入地理解群体极化现象的形成机制，更为业界就如何加强健康引导、提高公众健康素养，提供理论支持和实践指导。

Social media platforms, as crucial mediums for modern information dissemination, have increasingly highlighted their importance in the field of health information exchange. However, the openness and diversity of these platforms also make them gathering places for controversial health information. Scientists have not yet formed a consensus on their attitudes and opinions regarding such information, leading to conflicting academic viewpoints. On social media platforms, these conflicting viewpoints are often selectively quoted and interpreted, further exacerbating the binary opposition in health disputes. Therefore, discussions surrounding controversial health topics often exhibit a trend of group polarization.

To explore the evolutionary trends and causes of group polarization in online controversial health topics, this study selects "controversy over Traditional Chinese Medicine (TCM)" as a typical case. It collects all news articles related to "TCM" and "Chinese herbal medicine" published on the NetEase news platform from September 2019 to May 2020, including associated comments. Employing computational communication research methods and based on the theoretical foundation of social identity, this study delves into the influencing factors of group polarization.

The research findings indicate that as discussions deepen, the degree of group polarization shows a significant trend of exacerbation overall. Specifically, compared to homogeneous information environments, exposure to contradictory viewpoints tends to drive groups toward polarization, a trend particularly pronounced among those who support TCM. This finding challenges the traditional view that individuals exposed to diverse viewpoints can alleviate polarization. Instead, this study reveals that when groups encounter opposing information, they tend to entrench themselves in their respective "trenches," engaging in debate and rebuttal rather than seeking genuine dialogue and understanding, thus resulting in a "trench warfare" effect.

To further analyze the causes of this effect, this study employs critical discourse analysis. It finds that neither TCM supporters nor opponents attempt to use rational persuasion tactics on opposing groups. Instead, they mainly resort to labeling and personal attacks to ostracize the out-group, construct binary opposition relationships, attempt to associate both sides with individualism and irrational behavior, and under the emotional mobilization of nationalism, perceive the TCM issue as a matter of national stance, leading to further polarization in the TCM controversy.

Through in-depth analysis of the impact mechanism of group polarization in controversial health topics, this study reveals its essence and causes. This exploration not only helps researchers better understand the formation mechanism of group polarization phenomena but also provides theoretical support and practical guidance for the industry on how to strengthen health guidance and improve public health literacy.