Parental Punishment and Sibling Aggression

We suggest that powerful third-party mediators tend to support weaker antagonists in conflict situations and that this support inadvertently may encourage aggression. These principles are used to help explain aggression between fourththrough seventh-grade children and their siblings. We find that parents are more likely to punish older siblings than younger siblings for fighting, and that they are more likely to punish boys when theyfight with their sisters. This tendency to punish the more powerful sibling results in more frequent aggression, while a laissez-faire approach results in less frequent aggression. The results also show that aggression against siblings is more common when the age difference is three years or less, that girls are just as aggressive with their siblings as boys, and that physical aggression is more likely between siblings of the same sex.