Nobody wants to be lied to—especially by their own child. But it turns out when our little ones fib, it’s (at least initially) cause for celebrating another huge developmental leap: Lying is a sign children realize their parents don’t actually know all.

Researched shared by NPR explains that, before the age of four, kids have pretty simple understandings of the world; as far as they know, everyone has the same beliefs and those beliefs reflect reality. This is why very young kids think grown-ups know what they’ve done, even if the adults were not around when they did it.

Because these young kids can’t really separate belief and reality, they don’t try to lie.

Then the lies begin: Yes, I brushed my teeth, he says with chocolate still smudged on his gums. No, I didn’t stick my tongue out, she says when you clearly saw it in the rear-view mirror. And so on with the white lies only young children have the audacity to attempt.

Why do young kids begin to lie?

A recent study published in Developmental Science examined the reasons underlying preschoolers’ urges to fib. Over the course of 10 days, researchers pit kids and adults against each other with treats on the line.

The kids hid the treats and could win them back by providing deceptive information about the location of the goodies to the adults. At the beginning of the experiment the kids didn’t really have the skills to deceive, but by the end of the 10 days the little ones figured out how to lie. (Surely researchers sent apologies to the parents for returning the kids with sugar buzzes and new lying abilities.)

On the plus side, the game helped kids figure out the subjective nature of belief. Once that clicked for them, so did deceit. This research follows other studies that indicate kids who understand belief does not equal truth are more likely to lie than the kids who think belief is reality.

How to celebrate the development + tame the habit

Lying indicates a child’s brain is developing properly, but that doesn’t mean parents have to encourage or put up with it. There is a time and place for kids to flex their deceit muscles—such as games of hide-and-seek or go fish, which help kids understand the subjective nature of belief without, you know, lying. And when kids do start to play hide-and-seek without giving away their position, it’s time for some more involved conversations about lying.

Control your lies, too

Research out of McGill University indicates that kids’ propensities to lie is influenced by whether they think this behavior will cause harm to others or themselves. When parents get caught in lies, it sends mixed messages.

“Children get a lot of messages from their parents saying that lying is always bad, but at the same time they see their parents telling ’white’ lies to make life easier. Depending on their age, this is likely to be a bit confusing for children,” says Victoria Talwar, a Canada Research Chair in McGill’s Department of Educational and Counseling Psychology.

When your kid lies it’s time to talk about lying—and feel reassured this is simply a sign her mind is developing, not that she’s developing criminal habits. Not to mention, it makes for much more challenging games of hide and seek. ?