Kids may be able to tell when adults are saying truth, but not the whole truth

Cognitive scientists from MIT are in the process of tackling a question about whether children can tell when adults are telling them the truth, but not the whole truth.

Led by Laura Schulz, the Class of 1943 Career Development Associate Professor of Cognitive Science, the researchers found that not only can children make this distinction, but they can also compensate for incomplete information by exploring more on their own.

Determining whom to trust is an important skill to learn at an early age because so much of our knowledge about the world comes from other people, says Hyowon Gweon, an MIT postdoc and lead author of the paper.

In the first experiment, children aged 6 and 7 were given a toy to explore on their own until they discovered all of its functions. One group of children received a toy that had four buttons, each of which activated a different feature - a windup mechanism, LED lights, a spinning globe, and music - while the other group was given a toy that looked nearly identical but had only one button, which controlled the windup mechanism.

Then the children watched as a "teacher" puppet demonstrated the toy to a "student" puppet. For both toys, the teacher's instruction was the same: He demonstrated only the windup mechanism.

After the demonstration, the children were asked to rate how helpful the teacher was, using a scale from 1 to 20. Even though the teacher always demonstrated just the windup mechanism, children who knew the toy had three more undemonstrated functions gave much lower ratings than children who knew it was the toy's only function.

The second experiment began the same way, with the children exploring the toy, then seeing either a full or incomplete demonstration of its functions. However, in this study, the teacher then brought out a second toy. Although this toy had four functions, the teacher demonstrated only one.

Children who had previously seen a demonstration they knew to be incomplete explored the toy much more thoroughly than children who had seen a complete demonstration, suggesting that they did not trust the teacher to be fully informative.

The study has been published in the journal Cognition.