Deny All You Want, They'll Still Believe

Nov. 4, 2007 — -- Iraq and 9/11, sex trafficking, flu vaccines, widespread autism. Cognitive biases color our view of these and other issues and can affect our policy choices.

Because they are well-, but not widely understood, I'd like to briefly mention three of the most common ones and some related new and troubling research about denials.

First the biases.

1. The "availability heuristic" is the pronounced tendency of people to view any story through the lens of a superficially similar story that comes easily to mind or is psychologically available. For this reason, much of politics revolves around strengthening this tendency by keeping a preferred narrative uppermost in people's minds. It doesn't take too keen a political instinct, for example, to realize that some politicians' incessant invoking of 9/11 is an effort to keep it psychologically available, to help it color every aspect of the political agenda.

2. Another common psychological failing is called the "anchoring effect" and refers to our tendency to credit and easily become attached to the first number we hear about a particular phenomenon. If, say, an organization announces that there are X thousand new sufferers from some condition each year, the number may, even if grossly false, take a long time to debunk. Various groups, for example, announced a few years ago that 50,000 sex slaves were trafficked into the United States annually, and this very disturbing claim was taken up by The New York Times and other media. Nevertheless, although dozens of task forces and $150 million have been devoted to the problem since then, fewer than 1,500 cases have even been registered during the last seven years of effort.

3. "Confirmation bias" refers to the way we check a hypothesis by looking for occurrences that confirm it (as well as our amazing perspicacity) and ignoring those that do not. We "just know" something is true because it's the only possibility we consider as we search mightily for whatever might confirm our beliefs and pay scant attention to whatever might disconfirm them. Consider the Iraq war again, dot-com stocks or many medical snap judgments.

http://sitemaker.umich.edu/norbert.schwarz/files/07_jpsp_weaver_et_al_chorus.pdf

John Allen Paulos, a professor of mathematics at Temple University, is the author of the best-sellers "Innumeracy" and "A Mathematician Reads the Newspaper," as well as of the forthcoming (in December) "Irreligion." His "Who's Counting?" column on ABCNEWS.com appears the first weekend of every month.