Study: Kids Know When Adults Are Keeping Secrets

Lying about Santa Claus, how babies are born or whether there are cookies in the cookie jar could get parents into trouble. Children are extremely perceptive: past studies have shown that kids can tell when adults are lying to them. But telling children only part of the truth can get adults into trouble too. New research suggests that youngsters can tell when people commit “sins of omission” and even learn not to trust those people.

Researchers at MIT studied how 42 six and seven-year-olds evaluated information. They conducted two experiments. In the first study, the children were separated into two groups: one group got a toy that had four buttons, each of which performed a different function—lights, a windup mechanism, etc.; the other group got a toy that looked the same but only had one button, which activated the windup mechanism.

After the two groups of children had played with their respective toys, the researchers put on a show: a teacher puppet taught a student puppet how to use the toy, but only showed the student puppet the winup function. For the kids playing with the one-button toy, this was all the information; but for the kids playing with the four-button toy, the teacher puppet had left out crucial information.

The researchers then asked all the children to rate the teacher puppet in terms of how helpful it was on a scale from 1 to 20. The kids with the multi-functional toy noticed that the puppet hadn’t told them the whole story and gave it a lower score than the children with the single-function toys did.

The second experiment began with the same premise—splitting the children into two groups, letting them play with their simple or complex toys and then giving a puppet demonstration. But then after the demonstration, the researchers brought out another, totally different toy and gave it to both groups of children. This toy had four functions, and the teacher puppet demonstrated only one.

Children who had the multi-functional toy in the first part of the experiment—and therefore had seen an incomplete demonstration from that teacher puppet before—explored the toy more thoroughly than the children who only had the single-function toy. These children, it seems, had learned to not trust the teacher because of the first uninformative demonstration.

“This shows that children are not just sensitive to who’s right or wrong,” lead author Hyowon Gweon says. “Children can also evaluate others based on who’s providing information that is enough or not enough for accurate inference. They can also adjust how they learn from a teacher in the future, depending on whether the teacher has previously committed a sin of omission or not.”

So watch what you say parents: if you lie to your kids—or even keep secrets from them—they’ll learn to not trust you.