EMOTION TRUMPS MEDICINE:

Tempest In A C-Cup: The behavioral economics of mammograms. (Sally Satel, 11.25.09, Forbes)

There is yet a more subtle and global dimension to the mammography controversy: the power of natural cognitive biases in how we judge risk. In the words of MIT behavioral scientist Dan Ariely, we are often "predictably irrational." Humans are subject to numerous kinds of distortions in decision making.

The most obvious is the so-called status quo bias. This is a tendency to reject a new paradigm in favor of an established one without considering the merits of the new proposal. This is also called the Semmelweis reflex, named after a 19th century Hungarian physician who discovered that the mortality rate from childbed-fever could be slashed dramatically if doctors would wash their hands with a chlorine solution each time they delivered a baby. The wise doctor's suggestions for maternity care were not taken seriously for at least several decades.

Also relevant is "disconfirmation bias." This refers to the tendency to be critical of new information if it contradicts prior beliefs and, conversely, to accept information without much examination if it is consistent with prior beliefs. In a culture that touts screening early and often, the new guidelines collide with conventional wisdom. We humans also engage in "availability heuristics," the tendency to overvalue dramatic, salient information that comes easily to mind, like personal anecdotes (e.g., "But I know two women who got mammograms who detected breast cancer...").

Our "selective memory" leads us to forget about friends who got mammograms and had false positive scares as well as women who did get mammograms that did not detect their breast cancer. And our tendency to fall for "the emotional reasoning fallacy" causes us to conclude that something is wrong if it provokes emotion (e.g., "the Task Force is insensitive--if it saves just one life, it's worth it," or "these recommendations get me mad.")