It takes one to know one: Theory of mind helps children to detect lies that are revealed by semantic leakage

This study is the first to investigate children’s ability to detect lies signalled by semantic leakage and its relation to theory of mind (ToM). Data was collected from 128 Dutch-speaking children in the Netherlands, with ages ranging from 4 to 14 years (mean age 9). A verbal false-belief task was used to test children’s first- and second-order ToM. Their lie detection ability was tested by a picture-based oral story, in which one of the two story characters produced a lie signalled by semantic leakage. Children were 73% accurate in identifying the untruthful character by providing a justification referring to semantic leakage. Their performance improved with age. First-order ToM was a significant predictor, even after controlling for age. Previous studies have identified first-order ToM as a significant predictor of children’s lie production ability. Our findings, therefore, suggest that lie production and detection may partly rely on shared cognitive functions.