New research in Psychological Science finds that children taught to reason about others’ mental states are more likely to use deception to gain a reward.
Researchers report that developing “theory of mind” (ToM)—the ability to understand that other people have beliefs, desires, and perspectives different from one’s own—appears to give young children the cognitive tools to plan and execute intentional deception. According to the study, learning to reason about others’ false beliefs enables children to create a mistaken belief in another person’s mind, which is a key component of successful lying.
Previous studies have shown that many children begin to lie around ages two to three, and correlational work has linked theory of mind development with deceptive behavior. To move beyond correlation, psychological scientists Genyue Fu (Hangzhou Normal University), Kang Lee (University of Toronto), and colleagues designed an experiment to test whether improving children’s ToM skills causes an increase in deceptive behavior.
To identify children who had not yet begun to lie, the researchers used a hide-and-seek task combined with a reward incentive. Children chose a favorite sticker and were told they could keep it only if they won 10 candies in the game. During each trial, a child hid a candy beneath one of two cups while the experimenter closed their eyes. When the experimenter opened their eyes and asked where the candy was hidden, the experimenter would select the cup the child indicated. Thus, a child could obtain the candy only by misleading the experimenter about its location.
From the initial testing, the team selected 42 children who never lied across ten trials—these children consistently pointed to the true location of the candy. These three-year-old participants were then randomly assigned to one of two training programs: a theory-of-mind training group or a control group focused on quantitative reasoning tasks.
The ToM training centered on established false-belief tasks, such as the classic false-contents task. For example, children were shown a pencil box and asked what they believed was inside. After revealing that the box did not contain pencils, the instructor discussed what someone else—who had not seen the contents—would likely think was inside. The exercises aimed to teach children that knowledge and belief can differ across people: a child may know the true contents, but another person would hold a false belief based on appearances.
Both the ToM and control groups completed their respective training sessions every other day for a total of six sessions. After completing the training series, all children were re-tested on standard theory-of-mind measures and again participated in the hide-and-seek task to assess deceptive behavior.
As predicted, children who received theory-of-mind training improved on ToM tasks, whereas children in the control condition did not show comparable gains. Crucially, the ToM-trained children were also significantly more likely to lie in the hide-and-seek task compared with the control group. This increase in deception persisted when children were re-evaluated more than 30 days after training, indicating a lasting effect.
Although the study does not isolate which specific components of the training produced the change in behavior, the authors argue the findings provide experimental, causal evidence that enhanced understanding of mental states contributes to the emergence of lying and other sophisticated social behaviors. The sustained change suggests children did not merely memorize responses from training sessions; instead, they consolidated new knowledge about beliefs and applied it adaptively to solve a social problem.
In addition to Genyue Fu and Kang Lee, co-authors of the study include Xiao Pan Ding (University of Toronto), Henry Wellman (University of Michigan), and Yu Wang (Zhejiang Normal University). The research was published online in Psychological Science.
Funding: The work was supported by National Natural Science Foundation of China Grants 31371041, 31470993, and 31400898; Zhejiang Provincial Natural Science Foundation of China Grant LQ14C090001; the Social Sciences and Humanities Research Council of Canada; and Eunice Kennedy Shriver National Institute of Child Health and Human Development Grants HD047290 and HD022149.
Source: Anna Mikulak – APS
Image credit: Image adapted from the APS press release
Original research: “Theory-of-Mind Training Causes Honest Young Children to Lie” by Xiao Pan Ding, Henry M. Wellman, Yu Wang, Genyue Fu, and Kang Lee, Psychological Science. Published online October 2, 2015. DOI: 10.1177/0956797615604628
Abstract
Theory-of-Mind Training Causes Honest Young Children to Lie
Theory of mind (ToM) has long been considered central to children’s social functioning, but causal evidence linking ToM development to social skills has been lacking. This study tested whether explicit ToM training induces the emergence of lying in young children. After participating in ToM training focused on mental-state concepts, three-year-olds who had previously been unable to lie began to deceive consistently; this effect persisted for more than a month. By contrast, children who received control training emphasizing physical concepts were significantly less likely to lie. These findings provide the first experimental evidence that ToM plays a causal role in the development of social competence during early childhood.
“Theory-of-Mind Training Causes Honest Young Children to Lie” by Xiao Pan Ding, Henry M. Wellman, Yu Wang, Genyue Fu, and Kang Lee. Psychological Science. Published online October 2, 2015. DOI: 10.1177/0956797615604628