The next time you catch your child shouting out "it wasn't me" while standing next to a knocked-over house plant, fear not.

Ongoing research at the University of Toronto suggests a link between kids who are savvy liars and their future social success.

"Kids with juvenile delinquencies tend to be poor liars," says Kang Lee. "Kids who lie early, who lie better, are the kids who are going to develop normally.

"If you discover your two-year-old is telling a lie, instead of being alarmed, you should celebrate," says Lee, the director of the Child Development Research Group at the Ontario Institute for Studies in Education. "Your child has arrived at an important stage of his or her life."

Kang Lee is the director of the Child Development Research Group at U of T's Ontario Institute for Studies in Education. (Provided) Lee has spent more than 20 years studying how and why children lie.

He's found that by age two, about 30 per cent of kids are able to pull off a convincing lie. By age three, about 50 per cent can lie successfully. And by four, about 80 per cent can do it.

Lying signifies social savvy

Kids who aren't able to successfully lie alongside their peers tend to run into problems.

"These children will tend to tell lies more frequently and they can be easily spotted," says Lee, adding that this deficit makes socializing much more difficult. "The lack of social savvy can make a person develop abnormally."

The ability to pull off a convincing lie is a sign of two important milestones in a child's development:

the ability to recognize that what is going on in one's own mind is different from what's going on in someone else's mind (theory of mind); and

the ability to regulate one's behaviour and actions (executive functioning).

Without these two key milestones, children tend to lie poorly and frequently — and they tend to have conduct issues.

"Kids who develop typically tend to tell good lies," says Lee, adding that these "good" lies are so nicely crafted, even adults often can't tell they're lying.

Contrary to the commonly held belief that honesty is the best policy, there are "pro-social" reasons to lie.

"If we're going to be a thriving society, we have to learn to lie," says Lee. "We are social beings and we have to work with others. In some situations, we may have to tell lies to achieve that goal. That's why we should not blindly think that honesty is the only policy."

An example of pro-social lies are "white lies" that protect others' feelings, such as thanking your grandmother for a sweater she made, even if you think it's ugly.

David Livingstone Smith is the director of the Human Nature Project at the University of New England. (Provided) "It's so paradoxical — on one hand, we try to socialize kids to be honest, but if they're brutally honest, something's likely going to be wrong with them," says Lee. "I would never have anticipated this."

How lying protects

"We have a collective investment in dishonesty," says David Livingstone Smith, a University of New England philosophy professor and author of Why We Lie: The Evolutionary Roots of Deception and the Unconscious Mind.

"Lying oils the wheels of social interaction. A measure of dishonesty isn't optional. It's necessary."

He points out that lying can be very pervasive — to the point that we convince ourselves of our own lies.

"In order to do well in the social world, we need to deceive ourselves and project a shiny image of ourselves to others," says Smith.

He suggests a recent example of this is the case of NBC news anchor Brian Williams, who, over the course of a decade, told a false story about being in a helicopter being shot at in Iraq in 2003.

"It's very easy to misremember, especially when misremembering enhances one's position or status," says Smith.

Studies show that most people are consciously aware of lying once or twice a day. It doesn't happen more regularly, in part, Lee says, because if a person is caught in a lie, they risk become socially ostracized.