What not to do when your kid tells a lie

girl waiting to go in principal's office

We teach children that lying is naughty, but it’s actually a sign of some positive brain development.  


At the ripe old age of 3, my older daughter has begun flirting with falsehoods. So far, the few lies she has told have been comically bad and easy to spot. Her dad and I usually laugh at them with an amused, “Oh, yeah?” But now that I’ve stopped to consider, that strategy seems flawed.

While reporting a story on adult lying, I had the pleasure of talking with developmental psychologist Victoria Talwar of McGill University, who studies lying in children. I told her about an episode last week, in which I watched my older daughter swat my younger one. Instead of simply accepting reality and scolding her, my reaction was to question it further. “Did you just hit your sister?” After a pause, the guilty one offered a slightly confused “no.”

My accusatory question had created conditions ripe for this lie to be spawned. And now, as Talwar pointed out, I was dealing with two things: the hitting and the lie. “If you catch them in a transgression, just deal with the transgression,” she told me. “Don’t give them a chance to lie by asking a question you already know the answer to.”

Lying, it turns out, is actually a sign of something good happening in the developing brain. Dishonesty requires some mental heavy lifting, like figuring out what another person knows and how to use that information to your advantage. Many kids start experimenting with stretching the truth between ages 3 and 4. “In a way, it’s almost like they’re exercising a new ability,” Talwar says. “ And part of that is, ‘Mommy doesn’t know what I just did.’”

That thought sounds simple, but it’s actually quite profound. It means that a child is developing what scientists call theory of mind — the ability to understand the perspectives of other people and realize that those perspectives are sometimes different. It also means that a friend of mine who has put in years of hard work convincing her 5-year-old daughter that she is all-seeing and all-knowing may be out of luck soon. With a quickly solidifying theory of mind, her kid will wise up to her mom’s tall tale, if she hasn’t already.

For the rest of us parents who can’t maintain an elaborate charade like that, Talwar says the key is to create an environment that fosters truth-telling. “One of the most important ways to encourage honesty is to acknowledge it when you see it,” she says. If my daughter had answered yes to my ridiculous question, I should have thanked her for telling the truth before addressing the hitting. “Make sure they understand that you’ve appreciated that bit,” Talwar says.

Another strategy to minimize lies, as simple as it sounds, is to ask your kid to tell you the truth. Sweet little children, bless their hearts, just might comply, as a study from Talwar and colleagues suggests.

And remember, if you want your kid to value honesty, you should check yourself. One study found that children were more likely to lie after having been lied to. And lest you think you can skirt under their underdeveloped lie radars, consider a recent study. Children ages 6 to 11 were actually not terrible at detecting white lies. When watching a video of an adult or child saying that they thought a hunk of used, dingy soap was a good gift, or that a bad drawing of a person was actually good, children were about as good as adults in spotting fibs.

The result was interesting because it meant that children weren’t just swallowing adults’ lies, says study coauthor Michelle Eskritt of Mount St. Vincent University in Halifax, Canada. For these sorts of lies, kids weren’t just assuming that everyone was telling the truth, she says.

Now that my daughter is learning about honesty, we’ve been having some fun conversations about what the truth really is. These days she likes it when I make up stories that feature her telling elaborate whoppers. My lies about her lies really crack her up.

Laura Sanders is the neuroscience writer. She holds a Ph.D. in molecular biology from the University of Southern California.

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