In his book The Tipping Point, Malcolm Gladwell argues that “social epidemics” are driven in large part by the actions of a tiny minority of special individuals, often called influentials, who are unusually informed, persuasive, or well connected. The idea is intuitively compelling, but it doesn’t explain how ideas actually spread.

    The supposed importance of influentials derives from a plausible-sounding but largely untested theory called the “two-step flow of communication”: Information flows from the media to the influentials and from them to everyone else. Marketers have embraced the two-step flow because it suggests that if they can just find and influence the influentials, those selected people will do most of the work for them. The theory also seems to explain the sudden and unexpected popularity of certain looks, brands, or neighborhoods. In many such cases, a cursory search for causes finds that some small group of people was wearing, promoting, or developing whatever it is before anyone else paid attention. Anecdotal evidence of this kind fits nicely with the idea that only certain special people can drive trends.

    In their recent work, however, some researchers have come up with the finding that influentials have far less impact on social epidemics than is generally supposed. In fact, they don’t seem to be required at all.

    The researchers’ argument stems from a simple observation about social influence: With the exception of a few celebrities like Oprah Winfrey—whose outsize presence is primarily a function of media, not interpersonal, influence—even the most influential members of a population simply don’t interact with that many others. Yet it is precisely these non-celebrity influentials who, according to the two-step-flow theory, are supposed to drive social epidemics, by influencing their friends and colleagues directly. For a social epidemic to occur, however, each person so affected, must then influence his or her own acquaintances, who must in turn influence theirs, and so on; and just how many others pay attention to each of these people has little to do with the initial influential. If people in the network just two degrees removed from the initial influential prove resistant, for example, the cascade of change won’t propagate very far or affect many people.

    Building on the basic truth about interpersonal influence, the researchers studied the dynamics of social influence by conducting thousands of computer simulations of populations, manipulating a number of variables relating to people’s ability to influence others and their tendency to be influenced. They found that the principal requirement for what is called “global cascades”—the widespread propagation of influence through networks—is the presence not of a few influentials but, rather, of a critical mass of easily influenced people.

答案精析：根据题干中的dynamics of social influence可定位至文章第五段。根据第五段第二句可知，出现全球性影响链的最主要因素不是个别影响力人士的存在，而是因为有相当数量易受影响的人群，因此选择C项。

错项排除：文章讨论了社会风尚的发展靠人来推动和传播，而不是人本身被接受的问题，因此排除A项。文章提及如果在影响链中有一个环节的人们抵制流行的趋势，不愿被影响，那么潮流的影响力就会极大地降低，因此重要的不在于是否愿意影响别人，而在于是否愿意被别人影响，因此B项错误。原文未提及依赖他人，故排除D项。

长难句分析：They found that the principal requirement for what is called “global cascades”—the widespread propagation of influence through networks—is the presence not of a few influentials but, rather, of a critical mass of easily influenced people.

本句的主干为They found…that引导宾语从句。宾语从句中的主语为the principal requirement，两个破折号之间的部分为“global cascades”的同位语。

句意为：研究人员发现，实现“全球影响链”，即影响力通过人际网络实现广泛传播，其主要条件并非存在少数有影响力的人，而是存在很多容易受他人影响的人。