Consistent enforcement of rules is more important than the severity of the punishment itself, and children expect adults to treat every member of their group impartially and equally. Moreover, fair punishment brings emotional relief to children, according to research by scientists from SWPS University and the University of Michigan.
Children are keen observers, and their sensitivity to social injustice is evident from an early age. Even preschoolers are able to recognise situations in which rules are being broken, and expect that antisocial behaviour will be punished. As they get older, their sense of fairness becomes increasingly sophisticated: they not only expect that violations will be punished, but also understand that punishment should be proportional to the severity of a transgression.
Impartiality and equal treatment
In a study published in the Journal of Experimental Child Psychology (a follow-up to an earlier study by the same team, published in the journal Cognition ), as part of an international project, scientists Katarzyna Myślińska-Szarek, PhD (SWPS University) and Professor Felix Warneken (University of Michigan) focused on children's sense of fairness and their reactions to rule-breaking. Children from Poland and the United States, aged 6-9 (122 individuals), were shown picture stories in which characters engaged in a rule-breaking behaviours, for example, used smartphones at school or left mess after lunch. After watching a story, children answered a series of questions such as whether the character should be punished and whether the punishment was fair.
The primacy effect, previously described in a paper published in the journal Cognition , is crucial in children's assessment of situations. The decision made by a guardian or teacher regarding the first child who broke a rule sets a standard for subsequent instances. This means that if the first offender is punished, their peers believe the second should suffer the same punishment. If the first offender escapes consequences, children expect the second offender to be treated with the same leniency. Children are guided by so-called meta-norms, principles that dictate that rules must be applied impartially and equally to everyone.
In a more recent study, researchers also investigated what happens when both characters in a story face the same consequence - either both are punished or both escape punishment. They found that in this situation, almost all children (97%) believed the teacher did not need to change anything. However, when the consequences were different, as many as 93% of children demanded equal treatment. This shows that children focus not on punishment or its absence, but on equal treatment.
The results show that young children expect rules to be applied impartially and equally to every group member, and that being treated differently by an adult provokes strong resistance and undermines their sense of justice , says Katarzyna Myślińska-Szarek, PhD, a psychologist and sociologist from the SWPS University Faculty of Psychology in Sopot, the first author of the study.
The researchers also investigated whether it mattered if the characters in a story knew they were treated differently from their peers. It turned out that it was important: unless the story character knew what had happened to the peer, their emotions were assessed primarily based on their own punishment (or its absence). However, when the character learned that a peer had been treated differently, children were much more likely to attribute negative emotions (sadness, anger, guilt) to them regardless of the actual consequences. This demonstrates that children as young as six years old take into account what the person knows when assessing how they feel.
Punishment as an emotional reset
The experiment also yielded important observations on the psychology of emotions, related to how children perceive the consequences of breaking rules. A fair punishment does not evoke only negative emotions. While it may be unpleasant, it offers the punished child a sense of relief. Facing the consequences allows for closure for a difficult situation and releases the child from the burden of guilt.
Avoiding punishment, however, causes the initial joy of escaping the consequences to give way to guilt and sadness, especially when the child learns that another peer has been punished for the same offence.
Children do not analyse situations solely in terms of their own benefit. Their emotional reactions and assessment of situations depend on whether they know how others have been treated , explains Katarzyna Myślińska-Szarek. Leniency shown to one child in a group is not perceived as kindness, but as a violation of the principle of equality. Favouritism and selective enforcement of rules destroy a sense of fairness and cause discomfort even in the child who ultimately escapes punishment .
The results obtained among children from Poland and the US were consistent, confirming that sensitivity to double standards is universal and develops regardless of cultural context.
What are the implications of the study result for parents and teachers? It turns out that building authority and children's trust requires absolute consistency, because the first decisions after breaking rules establish the standard that children then expect to be consistently applied. Children measure the clarity and permanence of rules not by the severity of the punishments, but by whether adults enforce them impartially, predictably, and free from double standards, which is why it is important to ensure equal treatment.
Journal of Experimental Child Psychology
Experimental study
People
Awareness shapes fairness: how Children’s emotion atributions reflect sensitivity to unequal treatment
26-May-2026
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.