Why kids lie—and why it's not always bad

Jamie Goldfarb had finished reading the last bedtime book to her three-year-old son, Kai, when he told her he was hungry. The mom from Takoma Park, Maryland, usually complied with such requests since Kai had difficulty feeding as a baby. But this time, as she headed downstairs to fetch a banana, she heard him say under his breath, “Now that’s how you get a fourth book.”

Goldfarb was stunned that her sweet toddler would tell her an outright lie, but experts would say that Kai was engaging in sophisticated cognitive reasoning in his successful attempt for extra storytime. And according to researchers, lying begins as soon as a child starts developing empathy, reasoning, and self-control.

When they’re about two years old, kids start developing a sense of self, recognizing that they’re independent from others. And that means they can start figuring out—and manipulating—human emotions. Experts call this “theory of mind”—the ability to act based on how you anticipate the beliefs, desires, and actions of others.

“Kids start to know that, at least mentally, they’re independent from their parents. For example, Mom likes to eat broccoli, I like to eat chocolate,” says Kang Lee, a psychologist at the University of Toronto who’s researched children and lying for over 30 years. “Understanding that different people have different desires is very important. From there, a child can say, ‘Mom knows something I don’t know, but I know something Mom doesn’t know.’”

Although it might horrify parents, lying actually provides a rich workout for developing brains. And as a child’s brain develops, so too do the types of untruthful tales they might weave. Here’s where your kid might be on the Pinocchio scale—and advice from experts on dealing with your little liars.

The science behind why kids lie

Though experts agree that there’s no specific area in the brain dedicated for telling lies, certain regions of the brain are engaged during the construction of a lie. “The prefrontal cortex is involved in exercising self-control,” Lee says. “And the parietal area is involved in making reasoning about people’s mental states.”

The brain must also juggle emotions, memories, and knowledge about another person, as well as thinking about alternative paths the lie could take. “It’s really a whole network of complex interactions,” says Mary Helen Immordino-Yang, professor of education, psychology, and neuroscience at the University of Southern California.

And that’s why the ability to lie develops over time, as a young brain develops.

Starting around two years old, a child is probably going to tell her very first lie to keep from getting in trouble—and she probably won’t be very good at it. (For example, her face is covered in chocolate, yet she insists she didn’t eat any.) Although kids this age might see themselves as individuals, they haven’t yet mastered full command of their actions. So very young kids might blurt out the truth or start giggling when parents question their version of events.

“You actually have to inhibit the truth to tell a lie,” Lee says. “Imagine you ask your child to keep a secret. They just can't—their brain has not developed to this level, and they can't exercise sufficient control over it.” Toddlers may start to tell a lie, then change their story in mid-sentence because they lack the control—and mental stamina—to maintain the fiction.

That’s probably why Lee found that when pressed, the majority of very young children will eventually confess the truth. But fewer than half of three-year-olds fess up, likely because their brains are starting to develop the mental ability needed to tell a believable tale—and understand when they haven’t.

Older preschool-age children tend to try to lie as a way to make themselves look better, something experts call “impression management lies.”

“Kids might sometimes tell a lie because they want their parents' approval,” says Victoria Talwar, professor of educational and counseling psychology at McGill University and author of the upcoming book The Truth About Lying. “They may claim they did something that they didn't do because they want approval, or they exaggerate because they want the parent to think, oh wow, you're amazing.”

Talwar points out that very young children don’t often engage in impression management lies because they already believe that they’re wonderful.

As children enter elementary school, their more-developed brains are able to craft more complex lies. But they’ve also started to develop a sense of empathy and altruism—and that’s when those little white lies usually show up.

“These lies are told when you're thinking about the other person's feelings, especially in a cultural context when it may be seen as rude to be bluntly honest,” Talwar says.

How to handle your child’s lies

Parents might feel their trust has been violated when they catch their children being untruthful, but experts advise to avoid shaming them—or flat-out calling them liars. “That won't necessarily promote the behavior you want,” Talwar says.

Instead, she suggests parents focus on the behavior they’d like a child to exhibit and use language that encourages truth telling. For instance, if your kid claims he’s brushed his teeth but his breath tells another story, instead of saying, “Don’t lie about brushing your teeth,” parents could instead say, "We’ll read a book after you’ve brushed your teeth.”

When the lie is more involved, experts recommend having a direct conversation about it—after tempers have cooled. “You need to help that child unpack their motivations, their emotions, and the implications of lying,” Immordino-Yang says.

For instance, her young son decided to give himself a pretty bad haircut—then maintained for nearly two weeks that his hair had not been cut. Immordino-Yang says she helped him deal with his lie by first confronting him with the evidence (a clump of hair and a small pair of scissors hidden in his bedroom) then explaining the implications: Although his hair would grow back, he hadn’t been honest to people who trusted him. To help him take responsibility, she encouraged him to apologize to everyone he'd lied to. Immordino-Yang says his ordeal was emotional, but her son was truly remorseful—and soon went out to play.

For more serious lies like cheating and stealing, experts suggest parents first take a deep breath, then start an open dialog to understand the cause of the lie. After that, take measures to avoid repeating it.

Did the child cheat because he’s worried about getting a bad grade? Focus the discussion on study habits and ethics. Did the child steal because of a dare or because she wanted something she couldn’t afford? Talk about peer pressure or saving money. Experts then advise brainstorming what the child would do differently next time.

The most important way to minimize lying in children is for parents to model truthfulness. For example, refusing a request for a cookie by saying you’ve run out might prevent a tantrum. But once kids realize you’re not being honest, Immordino-Yang says they’ll start to believe that lying is how to get people to do what you want.

Talwar adds to make honesty part of an ongoing conversation. “Parents need to talk about [telling the truth] at other times, not just when you're dealing with someone’s lie,” she says. This could be praising a child for telling the truth in a difficult situation or calling attention to someone else’s honesty. ("Did you see that man return money to the cashier when she gave back too much change?") This reflects that honesty is valued in your family.

The ability to lie—and lie well—is a key part of a child’s social and emotional development. But Lee says parents should still look for warning signs that might mean a child needs help.

“If a child lies a lot—and lies poorly—you should be particularly concerned,” he says. A lack of remorse after being caught in a lie is another red flag. For older kids, lying can be an indication that something more serious is going on. (For example, a child lying about doing homework might actually be struggling with the topic.)

Lies might put both parents as well as kids in unpleasant situations, but Lee says he’s noticed one thing adults can take heart in: “I've seen almost 10,000 kids and done studies all over the world,” he says. “I've never met one child who would purposely lie to get someone else into trouble."