Children's moral judgments about acts of commission and omission with negative outcomes were studied based on their understanding of mental states. Children ( N = 142) in the first, third, and fifth grades made judgments about four tasks composed of two levels of mental states (first-order or second-order) and two types of acts (commission or omission). The results showed that the 7-year-olds responded considering only first-order mental states, but the 9-and 11-year-olds also used second-order mental states in their judgments. Whether the acts were commission or omission did not make a difference. These results indicate that children can make moral judgments regarding acts of commission and omission based on an understanding of second-order mental states by approximately the age of 9 years.

This study examined young children's understanding of second-order mental states, which have embedded structures such as beliefs about beliefs. Participants were 4-, 5-, and 6-year-olds. First-order and second-order false belief tasks were prepared with similar structures to minimize the difference between them. The results showed that over half of the 6-year-olds were successful on both tasks, while the 5year-olds were successful on the first-order but not the second-order false belief task. This time lag between understanding first-order and second-order mental states is consistent with the findings of previous studies. These findings suggest that information processing of embedded mental states is a significant factor for understanding second-order mental states.

No abstract

This study examined young children's deception in a conflict situation. A puppet show was prepared involving a protagonist who went into hiding, an enemy who wanted to catch the protagonist, and a friend who was looking for the protagonist. In the no-conflict condition, the enemy asked the children about the location of the protagonist. In the conflict condition, the friend asked the children; however, the enemy was nearby and could eavesdrop. Thus, there was a conflict between deceiving the enemy and telling the truth to the friend. In Experiment 1, the enemy hid behind a tree and was not visible to the friend; 80 children aged 4, 5, and 6 years old participated. In Experiment 2, the enemy was visible to the friend but was disguised; 24 children aged 5 and 6 years old participated. Most 5-and 6-year-olds did not give accurate information to the enemy in the no-conflict condition. However, in the conflict condition, most of the children did not control their behavior and immediately gave accurate information to the friend although the enemy was nearby. Young children from the age of 5 years were able to deceive in the no-conflict situation, but it was difficult for them to deceive in the conflict situation.

Omission bias refers to the tendency to judge acts of commission as morally worse than equivalent acts of omission. Children aged 7-8 and 11-12 years, as well as adults, made moral judgements about acts of commission and omission in two conditions in which the protagonist obtained a self-directed benefit. In the antisocial condition, the other person was harmed; in the selfish condition, the other person was not harmed. The results showed that adults and both age groups of children judged that the agent who did something (act of commission) was morally worse than the agent who did nothing (omission) for both antisocial and selfish conditions, although this judgement tendency was clearer in the selfish condition than in the antisocial condition. Agent intention was held constant across commission and omission, but most participants rated the intention of the agent who did something as stronger than that of the agent who did nothing. These results suggest that omission bias occurs regardless of differences in age and situation. In addition, perceived intention appears to change in conjunction with omission bias.