Children begin to tell lies, and to reason about lies told by others, during the preschool period (e.g., Lee, 2013). Most of the work on children’s telling and understanding of lies examines those told in self-serving contexts (to deny misdeeds) or in prosocial contexts (to spare the feelings of others). However, the vast majority of this work has been conducted within one context or the other: no study has reported children’s lie telling across contexts, and only one study compares children’s understanding of these different kinds of lies (Bussey, 1999). Although some research has
investigated how Theory of Mind and Executive Function relate to children’s telling of self-serving lies, little is known about how these abilities relate to children’s prosocial lie telling or to their understanding of lies.
The two studies reported here compared preschoolers’ understanding and telling of lies across self-serving and prosocial contexts, and to examine the roles of Theory of Mind and Executive Function in these abilities. In Study One, I found that both four- and five-year-olds could identify lies and truths in both contexts and demonstrated some understanding of the
emotional consequences of lie telling for the speakers. However, only five-year-olds were sensitive to the moral consequences of telling lies in self-serving and prosocial contexts. Further, different aspects of Theory of Mind were related to these different kinds of reasoning.
In Study Two, though fewer children took the opportunity to tell lies than expected, I found some support for a correspondence between children’s lie telling in self-serving and prosocial contexts. I also found some converging evidence for the findings of Study One with regard to preschoolers’ reasoning about lies
and truths in self-serving and prosocial contexts and the role of Theory of Mind in these abilities. However, children’s participation in lie telling tasks also influenced their reasoning about others’ lies. Taken together, this research demonstrates that important developments in children’s understanding of lies take place during preschool, and suggests that different aspects of Theory of Mind contribute to these developments. More work is needed to investigate children’s lie telling across contexts.