Researchers Taught Kids How to Lie. In the Name of Science, of Course.


Whatever happened to keeping kids honest? Preserving the innocence of youth? Promoting integrity? And now researchers have gone out of their way to encourage young children to tell a whopper.

But don’t worry, there’s actually a cool reason behind it.

Children learn to tell lies on their own at about 2 or 3 years old. For example, this cutie who is either lying, or about to star in a horror movie.

It’s also around this time in their lives that they begin to understand “Theory of Mind” (ToM). Which, essentially, is where we understand that we have certain ideas about things, but other people likely have different ideas about things.

So the researchers wanted to know: Is a child’s comprehension of ToM related to them learning how to lie?

Only one way to find out.


In order for the test to run properly, they played a game to weed out the kids who had already learned to lie.

The kids were told to hide a candy under one of two cups, while the researcher’s eyes were closed. Then the researcher opened their eyes and asked the child where the candy was. The child then pointed to which cup the candy was hidden under.

But here’s the catch: If the candy was under the cup the child pointed to, the researcher kept it. But if the child lied and said it was under the empty cup, the child would keep the candy.

So obviously the kids who knew how to lie, did lie. And all the honest children were ushered into the actual experiment.

The Actual Test Begins

The kids were split into 2 groups; 1 was given ToM training, 1 kept as a control group.

The children given ToM training were shown a pencil case, and then asked what they thought was inside it. After the children told them, the researchers showed them that it did not have pencils inside. “So,” they asked the kids, “What do you think other people might think is in the box?” Then the researchers helped them to consider that a new person looking at the box would still think it had pencils inside.

The kids in the control group played a similar game, but were not asked to think about what another person might think in a certain situation.

And then, after all that, all the kids took the candy test again.

The Lying Intensifies

Guess which group suddenly sprouted the ability to deceive the researchers?


The children who were encouraged to think about what another person believes now began to lie to the researchers.

The researchers conducted a follow-up a month after training finished. Lo and behold, the children clung to their newly-discovered Theory of Mind, and just as consistently lied to the researchers this final time.

Theory of Mind Unlocked a Huge Portion of Their Social Skills

The children weren’t just “mechanically learning” ToM. Rather, they internalized the concept and began to expand their social skills based on the new knowledge it afforded them.

Obviously understanding ToM is a necessary skill in social situations. And nearly every child learns it at some point. But next time, before you ask a child to guess what another person is thinking (“Do you think that could hurt their feelings?”), remember that you may also be teaching them to con you.