If your six-year-old is a seasoned little fibber, don't fret - it probably means he or she is unusually bright, according to a new study.
Scientists have found the first clear evidence that children who are good liars have better verbal working memories.
What this means is they are especially adept at keeping track of verbal information, a skill associated with being quick and clever.
The best liars were able to make and maintain slick cover stories for their lies without getting caught out, the researchers found.
Psychologist Dr Elena Hoicka, a member of the team from the University of Sheffield, said: "While parents are usually not too proud when their kids lie, they can at least be pleased to discover that when their children are lying well, it means their children are becoming better at thinking and have good memory skills.
"We already know that adults lie in approximately a fifth of their social exchanges lasting 10 or more minutes, so it's interesting to know why some children are able to tell more porkies than others.
"We'll now be looking to move the research forward to discover more about how children first learn to lie."
The study involved a quiz in which 114 six and seven-year-old children were tempted to cheat by peaking at an answer written on the back of a card.
First the children were given two easy questions: "what noise does a dog make?" and "what colour are bananas?"
They were then asked if they knew the name of the cartoon character Spaceboy. Each child was left alone with an upturned card on which the answer was written, and told not to peek.
The answer, Jim, was written on the back of the card in green ink with a picture of a monkey.
Unknown to the children, all this time they were being observed by a video camera concealed in a cardboard box. The scientists therefore knew who had looked at the back of the card and who had not.
Children who got the answer right, and claimed they had not cheated, were tested with "entrapment questions" based on the written answer and accompanying picture.
The children were asked if they could guess the colour of the writing or what the picture showed. If they covered their tracks by pretending not to know, or deliberately guessing wrongly, they were classified as good liars. Children who fell for one or both of the entrapment questions, revealing that they knew more than they should, were rated as poor fibbers.
For comparison, another group of children went through the same procedure but were given permission to peek at the card.
Tests were also conducted to measure each child's verbal and visuo-spatial working memory. The latter relates to storing multiple images at the same time.
The results, published in the Journal of Experimental Child Psychology, showed that good liars performed better in verbal working memory tests assessing both mental processing and recall.
In contrast, no difference in visuo-spatial working memory scores were seen between good and bad liars.
This may be because lying is less likely to require keeping track of visual images, the scientists believe.
US lead author Dr Tracy Alloway, from the University of North Florida, said: "This research shows that thought processes, specifically verbal working memory, are important to complex social interactions like lying because the children needed to juggle multiple pieces of information while keeping the researcher's perspective in mind."
Parents with children up to four years old can sign up for further research at the University of Sheffield through this website: https://www.shef.ac.uk/psychology/research/groups/developmental/index.