When do children start lying?

Angela Evans,
Associate Professor, Psychology
Faculty of Social Sciences
Children start lying around two years of age. (It) is the earliest signs of lie-telling that we’ve found to date. Lie-telling has been found to increase through childhood. So, around two years of age it’s a small percent of children, about 30 per cent of children will tell lies, and this increases by three years of age, about 50 per cent. By four years of age, we find that about 80 per cent of children will tell a lie to conceal their own transgression. This is maintained through childhood where the majority of children will lie to conceal a transgression that they’ve done.
We found that this is related to an increase in cognitive skills. Children’s thinking develops in childhood in relation to executive functioning skills. These are skills like being able to prevent yourself from doing something, being able to hold a thought in memory and being able to plan your next steps. When you think about telling a lie, this requires you to inhibit telling the truth, it requires you to hold in working memory the truth while planning an alternative statement, which would be your lie. All of these skills are required in order to tell a lie.
The other skill that we found to be related is something called theory of mind. This is the ability to put yourself in someone else’s place and understand that they have different thoughts and perspectives and you can instill false belief in the other person. You have to understand that you can manipulate someone else’s thoughts in order to be able to tell a lie.
Children are able to identify the difference between truth and lie around three or four years of age. I do recommend several techniques that we found to work really well with children to promote honesty. The first is really simple: simply asking children to promise to tell the truth before you question them about a transgression. Simply saying, “I want you to promise that you will tell the truth” and asking them to confirm that by verbally saying that they will tell the truth. We found that that dramatically increases truth-telling rates. We also found reading young children moral stories - there’s stories like George Washington and the Cherry Tree. George gets a hatchet for his birthday and he goes around chopping down all these cherry trees. His father asks him, “Do you know who cut down my cherry tree?” And he [George] says, “I cannot tell a lie, I cut down your cherry tree” and his father then praises him for telling the truth: “I’d rather have a son who tells the truth then 10,000 cherry trees.” Learn more about Research at Brock, by visiting brocku.ca/rese....