According to a new book, you only need TWO sentences to get your kid to tell the truth.  And if the secret to parenting really boils down to THAT, you're going to be FURIOUS at all the time and effort you've wasted.

Erick Barker is the author of a book called "NurtureShock:  New Thinking About Children".  And he says you only need TWO sentences to get your kid to always tell you the truth.

When you think your kid might be lying about doing something, tell them:  "I won't be upset with you if you did it.  And if you tell the truth, I'll be really happy."

Barker says those sentences significantly cut down on lying because, quote, "Young kids are lying to make you happy, to try to please you.

"So telling kids that the truth will make a parent happy challenges the kid's original thought that hearing good news, not the truth, is what will please the parent."

He also found another sentence that cuts down on lying by about 25%.  Say to your kid, "I'm about to ask you a question.  But before I do that, will you promise to tell the truth?"  (Lifehacker)