Adults with attractive faces are more likely to win the trust of children, psychologists say.
Scientists have tested 32 four- and five-year-olds shown 12 photos of women aged between 18 and 29, and they say both boys and girls tended to believe answers assigned to pictures of pretty women.
The photos had previously been selected from 56 original images by a panel of university students who rated their attractiveness.
Only the most attractive and unattractive were presented to the children.
Lead researcher Dr Igor Bascandziev, from Harvard University in the US, said on Thursday: "When learning about the world, children rely heavily on information provided to them by other people.
"Previous studies have shown children can be influenced by a range of factors such as whether the adult was correct in the past or if they are familiar to them.
"Our study wanted to examine whether children would trust an attractive stranger over an unattractive stranger."
Each child was first shown pictures of six novel objects and asked to name them.
Whether or not they guessed correctly, the researchers suggested they seek the help of one of two people.
At this point the children were shown two of the photos, one attractive and the other unattractive, and asked who they thought would know the answer.
After making their choices, the children were shown what each photographed woman said the object was.
They were then asked who they believed was right.
The results, published in the British Journal of Developmental Psychology, showed more children initially selected the attractive face, especially girls.
Both boys and girls tended to believe answers given by attractive-looking women.
"We see from the results that children and especially girls have more trust in attractive faces, even though there are no obvious reasons why people with more attractive faces would be more knowledgeable about object labels," Dr Bascandziev said.
"The gender difference could relate to boys not paying as much attention to the initial presentation of the faces or other research has pointed to the fact that females have superior face perception.
"It would be interesting to see future research explore whether children would continue favouring the more attractive face even when they have evidence that the more attractive face is unreliable and the less attractive informant is a reliable informant."
