Your six-year-old knows when you're lying, study shows

Children are remarkable judges of the people around them, with studies having shown them to be able to tell when someone is lying. Now researchers have found they pick up on more subtle aspects of misinformation such as when someone is telling only part of the truth.

In a paper published by the journal , scientists at the Massachusetts Institute of Technology have found that children can tell when someone is not giving them the whole story, and they learn not to trust the information that such a person gives them.

Understanding "sins of omission" might sound a sophisticated skill better suited to adults, but it is especially important for children. After all, most of the information they are absorbing from their surroundings is coming from adults telling them how the world works.

"Much of what we know about the world comes from what others tell us. However, informants can be ignorant, mistaken, withholding, or even deceptive," the study authors wrote. "Rather than indiscriminately accepting all socially communicated information, learners need to know whom to trust."

The MIT researchers wanted to know whether young children were capable of this sort of evaluation. So they recruited 42 children between the ages of six and seven who were visiting a Los Angeles children's museum, separated them into two groups and gave each group a different pyramid-shaped toy to play with.

One toy had only a twisting purple knob that controlled a wind-up mechanism; the other looked similar, purple knob and all, but also sported a button that triggered LED lights, a second button that caused a spinning globe to whirl and a third one that made music play.

After each group was allowed to play with its own toys, a "teacher" puppet demonstrated only one function to another puppet: the purple twist knob. For the single-use toy, this didn't matter. For the multifunctional toy, however, this meant there were three other uses that the teacher was leaving out.