Five-year-olds can see through your bravado

Imagine you wanted to lie to a five-year-old. “The toy shop is closed Billy,” you say, “it always closes at 2pm on a Monday.” You reason that if you make this announcement with confidence, then Billy is sure to believe you.

It’s not a bad strategy. In a new study involving nearly a hundred kids aged four to five, they were more likely to believe statements made by a woman who spoke and gestured with confidence, than those made by a woman who was hesitant and uncertain. In this case, the women’s comments weren’t about a toy shop, they were about the names of rare animals shown in pictures to the children (including a lanternfish and an Iberian lynx). These children had no prior experience with the women, so the women’s confidence was an important cue to whether they knew what they were talking about.

But the bluster strategy has a weakness. If you’ve lied or been inaccurate in the past, then your bravado is likely to be ineffective. The child, especially if aged 5 and upwards, will see through your confident facade and focus instead on your reputation for being wrong. “You said that about the sweet shop last week, Mummy, but when I went and checked, they were actually open. Therefore I don’t believe you now”.

The researchers Patricia Brosseau-Liard and her colleagues demonstrated this childhood ability by showing a new group of children short videos of two women making bold or hesitant statements about four animals the children were familiar with – including a duck and a whale. One woman was consistently confident but inaccurate, for example she said whales live in the ground. The other woman was consistently hesitant but accurate. After this experience, the children heard the same women telling them the names of four unfamiliar animals – each woman made a different claim about the correct name and the children had to choose who to trust. The women sustained the same confident or hesitant style throughout.

The four-year-olds were often swayed by the woman who had bravado, even though they’d just seen her get her facts wrong about four familiar animals. With each extra month of wisdom, however, there was a clear developmental trajectory in the sample, so that the older children were far more likely to trust the hesitant woman with a history of being right, than the confident woman with a record for being wrong.

This isn’t the first time that researchers have investigated children’s sensitivity to the confidence and past accuracy of speakers. But it’s actually only the second study ever to look at what happens when these cues collide. “Around the time of their fifth birthday children appropriately grant greater weight to someone’s prior reliability over that person’s current level of confidence,” the researchers said. “This form of emerging skepticism will serve them well as they navigate through a world selecting ‘better’ from ‘worse’ sources of information.”