New research has found that young children who are taught to reason about the mental states of others are more likely to use deception to win a reward.
The findings indicate that developing "theory of mind" (ToM) -- a cognitive ability critical to many social interactions -- may enable children to engage in the sophisticated thinking necessary for intentionally deceiving another person.
"Telling a lie successfully requires deliberately creating a false belief in the mind of the lie recipient, and ToM could provide an important cognitive tool to enable children to do so," the study said.
Psychological scientists Genyue Fu of Hangzhou Normal University in China, Kang Lee of the University of Toronto in Canada, and colleagues wanted to see if they could find causal evidence for a link between children's ability to understand other's thoughts and telling a lie.
The researchers first conducted a hide-and-seek task to identify children who had not yet started lying.
A total of 42 children who never lied were selected. The children, who were around three years old, were randomly assigned to complete either theory-of-mind training or control tasks focused on quantitative reasoning.
The theory-of-mind training included the standard false-contents task, in which children were shown a pencil box and asked what they thought was inside.
When it was revealed that the box did not actually contain pencils, they were asked to reason about what other people would think was in the box.
The children completed the training tasks or quantitative tasks every other day, for a total of six sessions.
After the sessions were complete, the researchers found that the children who received the theory-of-mind training were more likely to lie in the hide-and-seek task that required the kids to tell a lie to win a candy compared to those in the control group.
And this difference held over a 30-day period, the findings showed. The study appeared in the journal Psychological Science