People are sometimes tempted to lie for their own benefit if it would not harm others. For adults, dishonesty is the default response in these circumstances. The developmental origins of this phenomenon were investigated between 2019 and 2021 among 6‐ to 11‐year‐old Han Chinese children from China (N = 548, 49% female). Children had an opportunity to win prizes in a behavioral economics game (Experiment 1) or a temptation resistance game adapted from developmental psychology (Experiment 2). In each experiment, the youngest children showed a default tendency of honesty and there was an overall age‐related shift toward a default tendency of dishonesty. These findings provide direct evidence of developmental change in the automatic and controlled processes that underlie moral behavior.

This study used longitudinal cross-lagged modeling to examine the contribution of theory of mind (ToM), executive function (EF) to children’s lying development and of children’s lying to ToM and EF development. Ninety-seven Chinese children (initial Mage = 46 months, 47 boys) were tested three times approximately 4 months apart. Results showed that the diverse desire understanding and knowledge access understanding components of ToM, as well as the inhibitory control component of EF predicted the development of children’s lying, while the diverse belief understanding and false belief understanding components of ToM, and the working memory component of EF did not predict development of children’s lying. Meanwhile, children’s lying predicted development of children’s belief-emotion understanding components of ToM, but not any other ToM components, or EF components. These findings provide longitudinal evidence for the relation between ToM, EF, and children’s lying during the preschool years.

The relation between children' lying behaviour and their mental state understanding was investigated among a group of 3-and 4-year-olds (total N = 97). Two types of lying were examined: concealing-transgression lying, which was assessed using a temptation resistance paradigm, and competitive game lying, which was assessed using a hide and seek paradigm. Mental state understanding was examined using a theory of mind scale that assessed children's understanding of diverse desire, diverse belief, knowledge access, false belief, and belief-emotion. After controlling for age and verbal ability, children's concealing-transgression lying was not related to any type of mental state understanding, whereas children's competitive game lying was significantly related to their understanding of diverse belief and beliefemotion. These findings provide evidence that the cognitive correlates of young children's lying can differ as a function of the specific type of lie.

This research examined the effectiveness of using norms to promote honesty.Participants were Han Chinese children (N = 568, 50.4% male, 3.24 to 6.00 years, collected 2020-2022). Relative to children in a control condition, children in Study 1 were more likely to confess to having cheated in a game after being presented with a descriptive norm indicating that confessions are typical, or an injunctive norm indicating that most other children approve of confessing. Study 2 showed that this finding was not due to a methodological artifact, and Study 3 replicated the effect in a context in which the norm information was conveyed by someone other than the experimenter. The findings suggest that messages about social norms can influence children's honesty.