Because I Said So

Ah…Ken Jennings! The Jeopardy geek’s favorite. He’s our favorite, not just because he’s the big all-time long-lasting winner, but more because he combines encyclopedic knowledge, intellectual curiosity, sense of humor, and surprising humility.

I earlier reviewed his book Brainiacand I just noticed that I have never reviewed Maphead. I’ll have to fix that omission soon, as I read Maphead several months ago. But this review is about the latest Jennings opus, Because I Said So! The accurate but slightly sensationalistic subtitle is “The Truth Behind the Myths, Tales, and Warnings Every Generation Passes Down to Its Kids.” This lighthearted but serious book contains well over one hundred typical warnings and other advice that parents (well…mostly mothers) commonly say to their children. Jennings follows each example with a summary of scientific research into whether it is true or not. Actually, of them are black-or-white; although some turn out to be completely false, most turn out to finish somewhere other than either end of the truth-o-meter. Here is a small  sampling of the sayings, together with his final conclusion about each:

  • No swimming for an hour after lunch — you’ll cramp up! Turns out to be almost entirely false: “Not one water death has ever been attributed to post-meal cramping, and the American Red Cross doesn’t include any food warnings in its lengthy swimming-safety guidelines.”
  • I’ll bring you some chicken soup, you’ll feel better! Turns out to be mostly true. “The homemade Old World soup did just fine in the tests — better than a vegetarian control soup and much better than plain Nebraska tap water — but a few of the store-bought soups showed even better results. Don’t tell Grandma.”
  • Take off the Band-Aid and let the cut air out! Turns out to be entirely false. “Unfortunately, this advice has been outmoded since 1962, when a British doctor named George Winter published a groundbreaking study of moist wound healing in Nature magazine.”
  • You need eight glasses of water every day! Also turns out to be entirely false. “In 2002 a Dartmouth physiology professor and kidney specialist named Heinz Valtin studied the myth for the American Journal of Physiology and concluded that the ‘rule’ wasn’t just a lie, it was an accident. In 1945, the Food and Nutrition Board of the National Research Council recommended ‘one milliliter of water for each calorie of food’ eaten… ‘Most of this quantity is contained in prepared foods.’… A healthy adult in a temperate climate could probably replace his body’s daily water loss on food alone, without a single glass of water.”
  • Don’t feed the dog chocolate! Finally one that’s completely true. Cats are even more sensitive than dogs, but fortunately cats have more sense than dogs and are less likely to eat chocolate in the first place.

And I can’t resist mentioning the one math example:

  • It’s okay, even Einstein flunked math! This, of course, is 100% false. Einstein was a superb math student, so stop using this completely fictional story.

But you really have to check out all the details. As Jennings wrote this book for a mass audience, the details make for quick reading with no footnotes. Fortunately, however, he cites enough names and sources so that the reader can follow up his research and verify that his findings are sound, as you can see from a couple of the examples above. Read the book; you’ll be amused and enlightened. (And yes, it does resemble Mythbusters, Snopes, and Cecil Adams; Jennings duly credits all three.)

Categories: Books