Undue InfluenceA paper in the May 2007 issue of the Journal of Personality and Social Psychology "Inferring the Popularity of an Opinion from its Familiarity: A Repetitive Voice Can Sound Like a Chorus" (pdf) has excited considerable attention and comment in the blogosphere and rightly so.
In their research, Kimberlee Weaver (Virginia Tech), Stephen M. Garcia (University of Michigan), Norbert Schwarz (University of Michigan), and Dale T. Miller (Stanford) [WGSM] ran a series of experiments aimed at assessing how accurately individuals are able to identify group norms and opinions.
WGSM found that people tend to conclude that a familiar opinion is also a popular opinion. And, since an opinion can seem familiar just because one person has expressed it several times, a single individual can exert undue influence as people estimate what most members of a group think of a particular issue. In fact, WGSM found that the opinion of a single member of a group, if heard three times, can have about 90% the influence of the same opinion expressed by three different members of the group.1
There are policy consequences: A group can decide to pursue a particular strategy or path based on the view that a certain opinion is more widely held than is actually the case.
Because of this proneness for people to misgauge the popularity of aggressively advocated views, it is important to make your views known, rather than letting others dominate a discussion, especially when you disagree with them about something significant.
It is also important to publicize actual data concerning the distribution of different opinions, so that evidence-free claims about public opinion do not gain currency. For example, soundly gathered poll data concerning government policy options should be publicized so that the electorate has accurate knowledge of how popular opposing views are.
I first became aware of the WGSM study by reading a post on Jeremy Dean's PsyBlog. Dean seems to be a man after my own heart, interested in providing accurate, accessible reports concerning research findings. In explaining the rationale behind his blog, he says, "PsyBlog provides an insider's view of psychology without the journalistic sensationalism. Posts are based on articles in reputable academic journals, but without the academic terminology. It covers relationships, emotions, careers, work, stress, health, depression, music, personality, memory and loads more." If these are subjects you're interested in, you might like to keep tabs on Dean's blog. (He provides both an RSS feed and e-mail updates, to which you can subscribe.)
1 WGSM note an exception to the general tendency for oft-repeated views to be mistaken for wildly popular views: "... when participants had prior knowledge of the opinion ...[i.e., they already knew the group's position], they were able to correct their judgments and their group-level estimates were not affected by the number of opinion expressions they read."
You can read a summary of WGSM's work in a press release put out by the American Psychological Association.