"Because I Said So! is the MythBusters of old wives' tales. But beware: it could be a dangerous book if it falls into the wrong hands; namely your kids'. All of us can look back on the cautionary admonitions our parents and grandparents used to shout at us when we were in the middle of fun, and now our suspicions that they were hokum are verified! But we have to keep this to ourselves. If our kids get a hold of this book, we'll have nothing left to kill their joy with. So buy this book, read it, and then hide it away!"

– Ken Denmead, New York Times bestselling author of Geek Dad

“A fun, lighthearted compendium of conventional wisdom, mostly parental, which debunks plenty of old wives’ tales and urban myths while offering a few surprising truths…. ‘Occasionally Mom knew what she was talking about,’ as this clever book confirms, but often she did not.”

– Kirkus Reviews

"With his trademark with and genius. . . . Jennings imparts wisdom and good sense in this highly entertaining and oddly educational book."

– Publishers Weekly

"Sets aside esoterica in favor of the received wisdom of American parenting. . . . Jennings maintains his humor and warmth, keeping everything on the level of friendly, well-researched advice from the dad down the street who, by the by, would totally own your ass on trivia night at the neighborhood pub. Because I Said So! is breezy and illuminating, a mix that would be more volatile in less capable hands."

– The A.V. Club

"Armed with case histories, scientific finds and experiments on himself and his own children, Jennings let us in on what we really need to worry about ... and whether parents can now say 'I told you so!'"

– Los Angeles Times

"Jennings examines dozens of parental warnings, scoring their veracity against the most up-to-date scientific knowledge he can find. The result is highly engaging, occasionally surprising, and even somewhat useful. . . . If this book keeps one kid from having to wait an hour between eating and swimming, it will have done its job."

– Boston Globe

"Ken Jennings reveals the truth behind all those things you tell your children."

– Parade