Earlier false belief understanding predicts later lie-telling behavior in preschool children, but not vice versa

Young children's lie-telling behavior is associated with their theory of mind (ToM) development. However, current evidence is primarily based on cross-sectional studies, with very little longitudinal evidence on the causal relation between the two constructs. The current study provided much-needed cross-lagged longitudinal evidence on the association between ToM and lying in young children. Adopting a short-term longitudinal design, we tested 104 normally developing children's (64 boys, M = 54.0 months) false belief understanding and lie-telling behaviors three times at 4-month intervals. Results showed the cross-lagged model fit the data well. Lie-telling behaviors exhibited moderate stability across the three time points, while ToM exhibited moderate stability between the first two time points but not between Time 2 and Time 3. Earlier false belief understanding significantly predicted children's later lie-telling behavior, controlling for family socioeconomic status, child age, gender, only child status, and Time 1 verbal ability and inhibitory control. On the contrary, earlier lie-telling did not predict later false beliefs understanding. We concluded that earlier false belief understanding predicts later lie-telling behavior in preschool children, but not vice versa.