桑斯坦在著作《网络共和国》中提出“群体极化”的定义:团体成员一开始就有某些偏向,在审议后,人们朝偏向的方向继续移动,最后形成极端的观点。桑斯坦认为,群体极化对于传播市场而言是非常重要的,因为那么些有明确认同的团体持续致力于团体内的讨论。这种效应出现在无组织民兵、种族仇恨团队和其他较不极端的组织中。如果公众被瓜分,如果不同的团体各自设计一套他们自己喜爱的传播方式,结果将会造成更多分裂,将团队成员的初衷推向更极端。同时, Sunstein put forward the definition of “group polarization” in the book “The Internet Republic.” There are certain biases in group members from the very beginning. After deliberations, people continue to move in the direction of bias and finally form an extreme viewpoint. Sunstein believes that group polarization is very important for the spread of the market, because then there are clearly identified groups continue to focus on group discussions. This effect appears in militias, racial hatred groups and other less extreme organizations. If the public is divided, if different groups each design a set of their own favorite modes of transmission, the result will be more division and the team members’ original intention to be more extreme. Simultaneously,