Why So Much Bad Advice?

Why do bad ideas and bad advice seem to persist in a society with easy access to good science?  One reason may be the tendency to cling to beliefs then look for evidence to support them, instead of accepting the conclusions of well-designed experiments.  In his book The Righteous Mind Jonathan Haidt proposes that feelings and emotions come first, and that most reasoning works to justify rather than to test beliefs, that our “intuitions tend to drive our later reasoning.”  John Stuart Mill presented the same thought more than 150 years ago:  (paraphrasing) the more you argue, even while making clear, rational points, the deeper others dig in to protect long-held beliefs.  Adding to the sad situation are the effects of scientists and doctors who would rather become famous as authors or TV stars by promoting populist beliefs than risk challenging them, as they should, with the truth.

One case that comes to mind is the persistent belief that artificial sweeteners are dangerous.  Simple research is reassuring, but the belief is ingrained in our culture.  The National Cancer Institute states clearly and unequivocally:  “There is no clear evidence that the artificial sweeteners available commercially in the United States are associated with cancer risk in humans.”  The Mayo Clinic’s view is that “there's no sound scientific evidence that any of the artificial sweeteners approved for use in the U.S. cause cancer or other serious health problems.”  So who do Americans trust, these authoritative sources or a Facebook friend who watched some guy in a halloween costume on YouTube?

Likewise folk remedies of all kinds continue to circulate.  One longstanding belief is that magnetism has magical healing powers, leading people to buy bracelets, insoles and other magnetic devices.  This is odd because over the past 15 years the FTC has ordered Magnetic Therapeutic Technologies, among others, to stop advertising magnets as a cure for numerous diseases or even as a pain reliever.  No credible evidence exists of healing powers, and none can be claimed in their advertising.  One recent well-designed test of such devices confirms this fact concluding: “Wearing a magnetic wrist strap or a copper bracelet did not appear to have any meaningful therapeutic effect, beyond that of a placebo, for alleviating symptoms and combating disease activity in rheumatoid arthritis.”  Does that slow the sale of magnetic shoe insoles? – Not for people who don’t let the facts get in the way of a good story, a persuasive ad or a celebrity endorsement.

It’s your money to use as you please.  You can save it for college and retirement, give it away to companies selling you magnetic health devices, or even flush it down the toilet.  Two of those choices make the same amount of sense, but as Paul Simon sang, “A man hears what he wants to hear and disregards the rest.