Jaswal, V. K., & Malone, L. S. (2007). Turning believers into skeptics: 3-year-olds' sensitivity to cues to speaker credibility. Journal of Cognition and Development, 8, 263-283.
Abstract
Under most circumstances, children (and adults) can safely assume that testimony they hear is true. In two studies, we investigated whether 3-year-olds ( N = 100) would continue to hold this assumption even if the person who provided the testimony behaved in an uncertain, ignorant, and/or distracted manner. In Study 1, children were less likely to trust that, e.g., a key-like object was a spoon if the speaker indicated uncertainty about her testimony (e.g., “I think this is a spoon”) than if she simply labeled the object ostensively (e.g., “This is a spoon”). In Study 2, 3-year-olds were also more skeptical about a speaker's testimony when she had earlier made an obvious naming error and seemed distracted, but not when she either made an error or seemed distracted. These results indicate that 3-year-olds can respond differently to the same testimony, depending on the speaker's behavior.