Preschoolers' understanding of lies and innocent and negligent mistakes.

It has often been proposed that young children are not capable of distinguishing mistakes from lies and that they do not discriminate between the reactions that are generated by innocent and negligent mistakes. In our investigation, children aged 3 to 5 years were asked to choose whether a perpetrator had made a mistake or had lied about a food's contact with contaminants and were required to indicate whether this choice would produce a neutral or a negative reaction in the facial expression of a bystander. In this context, many children distinguished mistakes from lies and displayed an incipient ability to discriminate between lies and negligent mistakes that often generate negative reactions and innocent mistakes that do not.