Selective trust: children's use of intention and outcome of past testimony.

Children's epistemic vigilance was examined for their reasoning about the intentions and outcomes of informants' past testimony. In a 2 × 2 factorial design, 5- and 6-year-olds witnessed informants offering advice based on the intent to help or deceive others about the location of hidden prizes, with the advice leading to positive or negative outcomes. Informants then suggested to the children where to search for hidden prizes. Children trusted informants who had previously tried to help others more than informants who had previously tried to deceive others, regardless of past outcome. In addition, children trusted informants with positive past outcomes more than informants with negative past outcomes, regardless of intention. By varying intention and outcome independently, this study revealed that when children are deciding whether to trust testimony, they take into account the informant's mental states but also give slightly greater weight to the informants' past outputs.