Young children are especially trusting of things they're told

Previous research has found that three-year-olds are a credulous bunch; they believe most things they're told, and skepticism doesn't kick in until later. Vikram K. Jaswal, of the University of Virginia, wanted to look more closely at trust in three-year-olds. Through his work on how young children learn language, he became interested in what they do with what they hear. "Why are they so willing to accept somebody else's word, for example, that an eel is a fish, when it looks so much like a snake?" he asks. For this study, he and his students, A. Carrington Croft, Alison R. Setia, and Caitlin A. Cole, asked whether three-year-olds are more trusting of information they are told than the same information conveyed to them without words.

In one experiment, an adult showed children a red and a yellow cup, then hid a sticker under the red one. With some children, she claimed (incorrectly) that the sticker was under the yellow cup; with other children, she placed an arrow on the yellow cup without saying anything. The children were given the chance to search under one of the cups and allowed to keep the sticker if they found it. This game was repeated eight times (with pairs of differently colored cups).

The children who saw the adult put the arrow on the incorrect cup quickly figured out that they shouldn't believe her. But the kids who heard the adult say the sticker was under a particular cup continued to take her word for where it was. Of those 16 children, nine never once found the sticker. Even when the adult had already misled them seven times in a row, on the eighth chance, they still looked under the cup where she said the sticker was. (At the end of the study, the children were given all the stickers whether or not they'd found any of them.)

"Children have developed a specific bias to believe what they're told," says Jaswal. "It's sort of a short cut to keep them from having to evaluate what people say. It's useful because most of the time parents and caregivers tell children things that they believe to be true." Of course, there are times when people do lie to children -- about Santa Claus, for example, but also in less innocuous situations. Jaswal says it is useful to understand the specifics of children's trusting natures -- in this case, to understand that they believe what people tell them, but can be more skeptical about information delivered in other ways.