Deception is an essential part of children\'s moral development. Previous developmental studies have shown that children start to deceive at the age of 3 years, and as age increased to 5 years, almost all children were able to deceive for their own benefit. Although behavioral studies have indicated that the emergence and development of deception are related to cognitive abilities, their neural correlates remain poorly understood. Therefore, the present study examined the neural correlates underlying deception in preschool-aged children (N = 89, 44% boys, age 3.13 to 5.96 years, Han Chinese) using functional near-infrared spectroscopy. A modified hide-and-seek paradigm was applied to elicit deceptive and truth-telling behaviors. The results showed that activation of bilateral dorsolateral prefrontal cortex was positively associated with the tendency to deceive an opponent in a competitive game in the 3-year-olds. In addition, 3-year-olds who showed a high tendency to deceive showed the same brain activation in the frontopolar area as 5-year-olds did when engaged in deception, whereas no such effect was found in 3-year-olds who never engaged in deception. These findings underscore the link between preschoolers\' deception and prefrontal cortex function.

Children\'s advanced theory of mind (AToM) is concurrently associated with their prosocial lie-telling. However, the causal link between AToM and prosocial lie-telling has not yet been demonstrated. To address this gap, the current study adopted a training paradigm and investigated the role of AToM in children\'s prosocial lie-telling in middle childhood. A total of 66 9- and 10-year-old children who did not demonstrate any prosocial lie-telling in a disappointment gift paradigm at the baseline were recruited and randomly assigned to either the experimental group (n = 32) or an active control group (n = 34). The experimental group underwent a conversation-based training program of four sessions. The results showed significantly greater gains in AToM at the posttest for the experimental group children compared with the control group children, controlling for family socioeconomic status, children\'s literacy score, working memory, and inhibition. More important, the experimental group children were more likely to tell prosocial lies than the control group, even after controlling for the pretest AToM and other covariates. However, the training effects faded at the 6-month follow-up test after the training\'s completion. These findings provide the first evidence for the causal role of AToM in the development of prosocial lie-telling in middle childhood. The fade-out effect is discussed in the context of educational interventions.

Three preregistered studies examined whether 5-year-old children cheat consistently or remain honest across multiple math tests. We observed high consistency in both honesty and cheating. All children who cheated on the first test continued cheating on subsequent tests, with shorter cheating latencies over time. In contrast, 77% of initially honest children maintained honesty despite repeated failure to complete the tests successfully. A brief integrity intervention helped initially honest children remain honest but failed to dissuade initially cheating children from cheating. These findings demonstrate that cheating emerges early and persists strongly in young children, underscoring the importance of early prevention efforts. They also suggest that bolstering honesty from the start may be more effective than attempting to remedy cheating after it has occurred. RESEARCH HIGHLIGHTS: Our research examines whether 5-year-old children, once they have started cheating, will continue to do so consistently. We also investigate whether 5-year-old children who are initially honest will continue to be honest subsequently. We discovered high consistency in both honesty and cheating among 5-year-old children. Almost all the children who initially cheated continued this behavior, while those who were honest stayed honest. A brief integrity-boosting intervention successfully helped 5-year-old children maintain their honesty. However, the same intervention failed to deter cheaters from cheating again. These findings underscore the importance of implementing integrity intervention as early as possible, potentially before children have had their first experience of cheating.

Cross-situational inconsistency is common in the expression of honesty traits; yet, there is insufficient emphasis on behavioral dishonesty across multiple contexts. The current study aimed to investigate behavioral dishonesty in various contexts and reveal the associations between trait honesty, behavioral dishonesty, and neural patterns of observing others behave honestly or dishonestly in videos (abbr.: (dis)honesty video-watching). First, the results revealed limitations in using trait honesty to reflect variations in dishonest behaviors and predict behavioral dishonesty. The finding highlights the importance of considering neural patterns in understanding and predicting dishonest behaviors. Second, by comparing the predictive performance of seven types of data across three neural networks, the results showed that functional connectivity in the hypothesis-driven network during (dis)honesty video-watching provided the highest predictive power in predicting multitask behavioral dishonesty. Last, by applying the feature elimination method, the midline self-referential regions (medial prefrontal cortex, posterior cingulate cortex, and anterior cingulate cortex), anterior insula, and striatum were identified as the most informative brain regions in predicting behavioral dishonesty. In summary, the study offered insights into individual differences in deception and the intricate connections among trait honesty, behavioral dishonesty, and neural patterns during (dis)honesty video-watching.

Cheating is a pervasive unethical behavior. Existing research involving young children has mainly focused on contextual factors affecting cheating behavior, whereas cognitive factors have been relatively understudied. This study investigated the unique role of verbal and performance intelligence on young children\'s cheating behavior (N = 50; mean age = 5.73 years; 25 boys). Bootstrapping hierarchical logistic regression showed that children\'s Verbal IQ scores were significantly and negatively correlated with their cheating behavior above and beyond the contributions of age, gender, and Performance IQ scores. Children with higher Verbal IQ scores were less inclined to cheat. However, neither children\'s Performance IQ nor their Total IQ scores had a significant and unique correlation with cheating. These findings suggest that intelligence plays a significant role in children\'s cheating but that this role is limited to verbal intelligence only. In addition, this study highlights the need for researchers to go beyond the contextual factors to study the early development of cheating behavior.

Fake news impacts individuals\' behavior and decision-making while also disrupting political processes, perceptions of medical advice, and societal trends. Improving individuals\' ability to accurately assess fake news can reduce its harmful effects. However, previous research on media literacy interventions designed for improving fake news credibility assessments has yielded inconsistent results. We systematically collected 33 independent studies and performed a meta-analysis to examine the effects of media literacy interventions on assessing fake news credibility (n = 36,256). The results showed that media literacy interventions significantly improved fake news credibility assessments (Hedges\' g = 0.53, 95% confidence interval [0.29-0.78], p < 0.001). Gaming interventions were the most effective intervention form. Conversely, the intervention channel, outcome measurement, and subject characteristics (age, gender, and country development level) did not influence the intervention effects.

The interconnected power system connects the power grids of different regions through transmission lines, achieving power interconnection and resource sharing. However, data is transmitted through open power networks and is more susceptible to network attacks. To improve the stability of interconnected power systems under deception attacks, three scenarios of system security load frequency control were studied. Based on the construction of a dynamic model of load frequency control, an event-triggered strategy was used to reduce the communication frequency between nodes, resulting in a reduction in the amount of network transmission data. A sliding mode controller was constructed to solve the problem of event-triggered sliding mode security load frequency control. Elastic event-triggered sliding mode load frequency control for interconnected power systems under mixed attacks. The simulation results showed that using the load frequency control model triggered by events, the load frequency deviation of the interconnected power system can be stabilized at around 12 seconds, effectively saving the cost of network resources. Under the regulation of the load frequency control model based on sliding mode control, the interconnected power system stabilized in 10 seconds, reducing the load of network transmission. The elastic event-triggered sliding mode load frequency control model can ensure stable transmission of power data under various attacks and has good anti-interference performance. The results of this study have played an important role in achieving the stability of power resource supply. Compared with previous studies on individual power systems, this study solves the attack problem of interconnected power systems and considers the frequency control problem of system security loads under mixed attacks, enabling the system to recover stability faster.

Trust and honesty are essential for human interactions. Philosophers since antiquity have long posited that they are causally linked. Evidence shows that honesty elicits trust from others, but little is known about the reverse: does trust lead to honesty? Here we experimentally investigated whether trusting young children to help can cause them to become more honest (total N = 328 across five studies; 168 boys; mean age, 5.94 years; s.d., 0.28 years). We observed kindergarten children\'s cheating behaviour after they had been entrusted by an adult to help her with a task. Children who were trusted cheated less than children who were not trusted. Our study provides clear evidence for the causal effect of trust on honesty and contributes to understanding how social factors influence morality. This finding also points to the potential of using adult trust as an effective method to promote honesty in children.

Collaborative crime poses severe social hazards. In collaborative crime scenarios, previous studies have indicated that perpetrators\' collaborative encoding can impair the detection efficiency of P300-based complex trial protocols due to the collaborative encoding deficit. The feedback concealed information test (fCIT), a unique variation of the concealed information test, provides participants with feedback on how well they conceal information from memory. The fCIT, which has proven to be highly efficient, detects concealed information using recognition P300 along with feedback-related event-related potentials, and reflects the subject\'s motivation to conceal. However, no studies have examined the fCIT\'s effectiveness in identifying collaborative criminals. We propose that the fCIT\'s efficiency persists in cases of collaborative crime and test this hypothesis using a sample of 48 participants. The participants in the collaborative groups were instructed to have hushed conversations about theft to simulate the collaborative crime process. Subsequently, they completed the fCIT. The findings indicate a significant decline in recognition P300\'s detection efficiency when participants committed crimes collaboratively. Nevertheless, the detection efficiency of feedback P300 and feedback-related negativity remained high. This study\'s outcomes illustrate the capacity of the fCIT to detect perpetrators involved in collaborative crime.

This research, comprising three preregistered studies, investigated the link between self-efficacy and cheating on an academic test in 5- and 6-year-old children. Study 1 assessed children\'s general self-efficacy and found it to be unrelated to their cheating behavior. Study 2 assessed task-specific self-efficacy, which was not found to be associated with cheating. In Study 3, children were randomly assigned to either an experimental group, which received brief positive feedback on task-specific self-efficacy, or a control group, which received no feedback. The experimental group demonstrated significantly less cheating. These findings, for the first time, identify a specific connection between young children\'s self-efficacy and academic dishonesty and suggest that positive feedback on task-specific efficacy could be a simple effective strategy for fostering academic integrity early on.