Children who lie early in their life tend to have much better cognitive abilities, a study claims.

"As parents and teachers -- and society as a whole -- we always worry that if a kid lies there will be terrible consequences," said Kang lee from the University of Toronto in Canada.

"But it turns out there is a big difference between kids who lie earlier and those who lie later. The kids who lie earlier tend to have much better cognitive abilities," lee said.

In the study published in the Journal of Experimental Child Psychology, researchers asked 42 preschool-aged children in China -- who showed no initial ability to lie -- how to play a hide-and-seek game.

They were split into two groups with an equal number of boys and girls, with an average age of about 40 months.

Over four days, they played a game in which they hid a treat, such as popcorn, from an adult in one hand.

The grown-up had to choose the hand that the child indicated.

If the child successfully deceived the adult, they got to keep the treat, researchers said.

The experimental group of kids was taught how to lie in order to win the game while the control group was not.

On standardised tests used to measure executive function, including self-control and "theory of mind" -- the capacity to understand another person's intentions and beliefs -- the kids who were taught deception out-performed the control group.

"With just a few days of instruction, young children quickly learned to deceive and gained immediate cognitive benefits from doing so," the researchers said.

"These findings support the idea that even seemingly negative human social behaviours may confer cognitive benefits when such behaviours call for goal pursuing, problem solving, mental state tracking, and perspective taking," they said.

However, the researchers caution that it is not a good idea to throw out conventional wisdom and actually teach kids to lie.