You Know What They Say

The Truth About Popular Beliefs

(New York: Harper Collins, 2014)

You Know What They Say - Allfie Kohn

Everyone knows that boys are better than girls at math, that spicy foods upset the stomach while milk is soothing, and that lemmings drown themselves en masse. Likewise, we all believe that strange things happen during a full moon, that people become more conservative as they get older, and that stomach cramps will sink a swimmer who goes in the water too soon after eating.

The only trouble with all this common knowledge is that it’s wrong. Rarely, in fact, do we bother to question what “everyone knows,” let alone check whether common beliefs are supported by good research. But Alfie Kohn has systematically investigated how much wisdom there is in folk wisdom:

  • From a research plane high over Wisconsin comes proof that two snowflakes can indeed be alike.
  • From dozens of psychologists comes word that birds of a feather flock together a lot more often than opposites attract.
  • From a laboratory in Ireland comes a brand-new report suggesting that your mother may have been right when she told you to stop cracking your knuckles.
  • From recently declassified government documents comes disturbing evidence that the United States didn’t need to drop atomic bombs on Hiroshima and Nagasaki – the Japanese were already about to surrender.

In all, Kohn offers a careful look at about eighty popular assumptions and ends up debunking a good deal of conventional wisdom. In the process, he offers a model of healthy skepticism and provides some valuable analytical tools for evaluating the things we hear. You Know What They Say… is witty and well-researched, packed with surprising facts that readers will soon be quoting to their friends.



What people are saying


“By mingling his own observations with experts’ findings, Kohn refutes dozens of commonplace proverbs pertaining to human behavior, nature, health, and world history . . . . The author’s crisp prose and agile wit keep pedantry at bay.”

— Boston Herald

“Bound to entertain as well as set the record straight.”

— Science News


Where to buy it


You Know What They Say…, alas, is officially out of print. However, Alfie Kohn has a limited number of his own copies available. If you are interested in obtaining one, please leave us a message at the e-mail address listed for questions & comments on the Contact Us page.