Skeptics believe that we should accept or reject claims according to scientific evidence. Unfortunately, what persuades most people has little to do with the logical and scientific support for a claim. Most people, including many who call themselves skeptics, become persuaded not by logic or science but by emotional and other non-evidential aspects of arguments. Dramatic examples of such non-scientific and irrational bases for belief can be found in what is called “the framing effect.” Daniel Kahneman (Thinking, Fast and Slow) describes framing as follows: “Different ways of presenting the same information often evoke different emotions.”

An experiment by Amos Tversky at the Harvard Medical School in 1982 provides an example. The participants were physicians. Their task was to decide, on the basis of outcome statistics, whether to recommend either surgery or radiation for their patients with lung cancer. Half of the physicians were told that, “The one-month survival rate for surgery is 90%.” Given this information, 84% of the physicians chose to recommend surgery over radiation.

The other physicans were provided with this information about surgery outcomes: “There is a 10% mortality rate in the first month.” Given this latter information, only 50% of the physicians recommended surgery. As you may have realized, the two statements describe the same outcome. However, when the same outcome statistics are framed in terms of “survival,” substantially more physicans (as well as patients) choose the surgery. But when the outcomes are framed in terms of “mortality” the percentage of physicians who choose surgery drops greatly. Such framing effects have been demonstrated in politics, medicine, food choices, advertising, and all areas in which people make choices. This year, the Skeptic’s Toolbox will examine framing effects in journalism, medicine, politics, and other areas in which people have to choose to believe or reject dubious claims. We will focus not only on how framing changes the acceptability of a claim, but also the backfire effect—which refers to how providing evidence against a claim often strengthens, rather than weakens, the belief in that claim.