Can't Handle the Truth? Kids Know If They Don't Get the Full Story

Image: A father and daughter walk in a city center
A father and daughter walk in a city center.Sean Gallup / Getty Images file

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So where do babies really come from, mom?

Kids can tell whether an adult is telling them the truth –- but not the whole truth –- according to a new study, and adjust their behavior when they sense a person may not be entirely trustworthy.

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In two experiments involving children ages six and seven, researchers from the Massachusetts Institute of Technology found that kiddies know when a teacher is being more or less helpful, and save that information for the future.

When the kids didn’t feel like a teacher was giving them all the information, they were more likely to seek it out on their own, according to the study.

“When we teach others, we inevitably omit lots of information –- we simply can't tell others everything about everything,” said Hyowon Gweon, a post-doctoral associate at MIT and lead author on the study, in an email.

Children will "explore more” when taught by teachers who previously withheld information, Gweon wrote.

Children in the first of two experiments watched as teachers –- in this case a hand puppet instructing an Elmo doll -– demonstrated how to use certain toys. The youngsters then graded the teachers on whether they did a “very good job,” “just okay,” or “not a good job.”

In a second experiment, the children watched the same teachers show how to use a new toy -– but not necessarily everything the toy could do. If the teacher had shown that he or she was untrustworthy in the first experiment, the kids wanted to play with the new toy more to see what else it could do.

The study shows how kids are equipped to operate in a world where what people say often has shades of grey, the researchers said.

“This study is a good example of how children's understanding of other people around them and their exploration of the physical surroundings mutually affect one another,” Gweon said.