Children tend to punish norm transgressions, even when they are mere external observers—a phenomenon known as third-party punishment. This behavior is influenced by group biases, as children unevenly punish in-group and out-group members.Two opposing hypotheses have been proposed to explain group biases during third-party punishment: the Norms-Focused Hypothesis predicts that individuals punish more harshly selfishness by in-group than by out-group members; contrarily, the Mere Preferences Hypothesis predicts that people are more lenient to selfishness by in-group than by out-group members. Here, we tested these hypotheses in children between six and 11 years of age (N=124) and explored the mechanisms underlying group biases during the development of third-party punishment. Our results supported the Norms-Focused Hypothesis: children preferentially punished unfair sharing from in-group members evidencing in-group policing bias, and they were also more willing to punish selfishness directed at in-group members than out-group members, showing in-group favoritism bias. We observed different developmental trajectories and mechanisms associated with these biases: while in-group policing remained stable over childhood as automatic as well as more effortful and controlled processes, in-group favoritism increases with age and was manifested only in the context of more controlled processes. These results shed light on the mechanisms underlying the development of third-party decisions and could be used to plan strategies and interventions to manipulate group biases in children.
Application of the fractional-order model in the problems of identification and order reduction for the controlled processes
