Lies, Damn Lies, and Statistics

PinocchioA recent article shows that your toddler may not be telling you the whole truth.

Recently, Canadian professors Angela Evans and Kang Lee created a little media buzz with their new study in which they show that 2-year-old will tell lies if put in certain situations. While the work they did is important, I had a few problems with the way Dr. Lee and Dr. Evans conceptualized “lying”, as well as some concerns about the statistics they presented in the article.


Dr. Lee and his colleagues conceptualize lying development in three stages. The first stage is primary lies, and it is defined as “deliberately mak[ing] factually untrue statements”. The second stage of lying development is secondary lies, and it includes “a statement made with an intent to instill false belief into the mind of the recipient”. Today I’d like to focus on those two stages (the third stage is maintaining a lie, and it’s a bit more complicated).

Why Do Children Lie?

Children typically make untrue statements when they have broken the rules and are trying to avoid punishment (‘I didn’t do it’), to protect self-interests (‘that toy is mine’), or to portrait themselves in a positive light (‘that didn’t hurt at all’). The argument is that even 2-year-olds say these kinds of things (for example, deny that they have peeked when asked not to peek), and therefore, even though you can’t really tell if they are trying to “instill false belief into the mind of the recipient”, they are doing some rudimentary form of lying.

Is it Really Lying?

The problem is that without the intent to create a false belief, can you really call it lying? My son recently told me, “mommy, there’s a dinosaur in the back yard”. This was clearly an untrue statement, but I’m not yet willing to say that he lied. Knowing 3-year-olds, I find they often say stuff that go through their head without any intention of making any impact on the world, let alone other people’s minds. It could be that he dreamt there was a dinosaur in the back yard (this was right after I woke him up one morning). It could be that he wanted to see a dinosaur, so he imagined one coming for a visit. But I highly doubt he wanted me to think there was a dinosaur in the back yard.

Lying Is a Skill

Dr. Lee noted in the interview that lying requires quite a few skills. It requires having a Theory of Mind (reasoning about other people’s mental states) and being able to suppress telling the truth (a skill called inhibitory control), among other skills. Both these skills are not well developed in 3-year-olds, and I doubt they can use and coordinate them to such an extent.

Those Damn Statistics

Another point to make is that really, only 25% of the 2-year-olds in the lying study actually lied, while 95% of them peeked when they weren’t supposed to. So most 2-year-olds would break the rules, but very few of them would lie about it. This tells me something about 2-year-olds’ ability to follow rules, but I’m still not convinced that 2-year-olds can lie. For example, the other day I left my 20-month-old alone in her high chair during breakfast. When I came back 2 minutes later, I asked her “did you spill your cereal?” and she said “no”. I hardly think she lied in order to get away with spilling her cereal; she looked genuinely amazed when she looked down and found her cereal on the floor.

Teachable Moments

That said, Dr. Lee said something very interesting in the interview. While lying is a milestone of normal development that indicates sophisticated cognitive skills, it is still up to the parents to teach the moral implications of lying.

By the way, one of the projects currently running in our lab is about children’s understanding of lies. If you are a parent of a preschooler in the Ottawa area and want to participate in the project, here’s how.

Do your kids lie? What about? What do you do about it?

@2015 - Gal Podjarny