Young children understand more about how beliefs work than researchers once thought, according to new research co-authored by Faculty of Liberal Arts & Professional Studies Assistant Professor Laura K. Soter.
For decades, researchers have known that children gradually learn that different people can hold different beliefs and that beliefs can change when new information becomes available. Studies have also shown that children recognize that some people are more certain of their views than others and some forms of evidence are more convincing than others.
What had remained largely unexplored was whether children understand how these ideas fit together. Can they recognize that the strength of a person's belief affects how willing that person may be to change it?
"A key idea in theories of rationality is that beliefs can come in different degrees of strength, and that that strength shapes how easily beliefs ought to be updated. If you’re really sure of something, it will take a lot more evidence to convince you to change your mind, compared to something you’re not very confident in," says Soter. "No work had looked at when and whether children become sensitive to that feature of belief."
The question is important because belief revision plays a central role in everyday social life. By understanding when children begin to recognize that some beliefs are harder to change than others, researchers can gain a better picture of how children's social reasoning develops and how they learn about persuasion, disagreement and evidence. It may also help explain how children decide whether it is worth trying to change someone's mind and how they come to judge others as open-minded, stubborn or receptive to new information.
"If we want to understand the development of children’s theories of what makes someone a rational agent, this is an important piece of that landscape," says Soter.Â
, Soter and collaborators at the University of Wisconsin and Duke University conducted two studies involving 199 children between the ages of four and eight.
In the first study, children were introduced to pairs of characters who shared the same belief but differed in how strongly they held it. One character believed something "a lot" and was very sure about it, while another believed the same thing only "a little" and was less certain. Researchers asked children whether each character could change their belief, how easy or difficult that would be and how such a change might happen.
In the second study, characters were presented with evidence that contradicted their beliefs. Children were asked whether the characters would keep their original view or change their minds after hearing new information and how strong their updated belief would be.
The results revealed a clear developmental pattern. Children generally understood that both weak and strong beliefs could change. Researchers were impressed by how early this understanding emerged. "We thought we might not see a sensitivity to belief strength until around age six, but we saw evidence for it emerging reliably by age five," says Soter.
At that age children increasingly judged strongly held beliefs as harder to change and less likely to be revised than weakly held beliefs.
They also found that when presented with the same contradictory evidence, children predicted that characters with weaker beliefs would be more likely to change their minds, while those with stronger beliefs would be more likely to stick with their original view.
Another notable finding came from the children's explanations. When asked how someone might come to change a belief, most pointed to evidence, such as observing something firsthand or hearing new information from others. Very few suggested that people simply decide to think differently for no reason.
The findings add to researchers' understanding of how young minds make sense of the people around them. The study suggests that even at a young age, children are beginning to grasp a fundamental aspect of social life: not all beliefs are held equally strongly, and not all minds are equally easy to change.