A friend was recently telling me how his three-year-old granddaughter was convinced that the dandelion flower gone to seed was a clover. Her conviction could not be shaken, because this received wisdom had been handed down from her mother—the person who is, at that age, the font of all knowledge. Her mother had really said of the wispy round seed ball that it was a blower. The little girl misheard. But there was no going back. She was proud of what she knew. It was a clover. Period.

It’s a cute tale when it involves something so inconsequential, but much of our received wisdom is wrong, yet we refuse to review and reevaluate that knowledge, so certain are we that it is based on sacred texts or an unassailable source.

Sometimes the misrepresentation is as accidental as the blower clover. A freelance writer I know who was researching the history of the Howard Theatre in Washington, D.C., found, for example, that claims it had launched the career of Ella Fitzgerald were based on a misreading of an original story. Once the claim was made, it was repeated so often in print that the multiplicity of reports gave it the appearance of validity. It became part of the history.

Sometimes the misinformation is intentional. The first rule of propaganda is that a lie oft repeated becomes true. As historian Barbara Tuchman notes in Proud Tower, her book about the world just before World War I, when the French wrongly convicted Captain Alfred Dreyfus of treason, “The unanimity of the military court seemed confirmed by a published rumor that Dreyfus had confessed, which, as it passed from journal to journal, acquired the force of an official statement and satisfied the public.”

More recently, the New York Times had an article about how the United Nations was able to deflect charges that a contingent of the U.N.’s foreign volunteer forces from Nepal had brought cholera to Haiti. The U.N. played on the world’s faith in the integrity of the U.N. and willingness to blame Haiti’s poor sanitation and conditions created by the earthquake.

The media propagated that line, but now forensic analysis shows that the cause was indeed infected Nepalese troops.
Sometimes opinions harden into doctrine with little supporting evidence. Everyone believes they need eight glasses of water daily. Repeated news investigations find absolutely no basis for the claim. It has become dogma nonetheless. Many other “truisms” deserve a skeptical second thought.

So how can we clean our mental house of such dross? French philosopher Rene Descartes said it best, “[I]t is necessary that at least once in your life you doubt, as far as possible, all things.”

More than once in your life is probably even better. Security professionals can apply that principle by periodically questioning everything from the assumptions behind risk management strategies to the accepted wisdom of who commits crimes.