Moderators of the disapproval of peer punishment

Recent studies have found disapproval of peer punishment of norm violations. This seems puzzling, given the potential benefits peer punishers contribute to the group. We suggest part of the answer is that peer punishers tend to come across as aggressive and as such may be viewed as more problematic than beneficial to have around. We used simple computer animations of geometric shapes to enact 15 precise variations of social sanctions against a norm violator. More than 1,800 subjects were recruited to watch an animation and judge the behavior and character of the animated agents. They also completed a trait aggression measure. Across the variations peer punishment was typically disapproved of, especially when severe or openly aggressive, and especially by subjects low on trait aggression. We conclude that there seems to be a social norm against peer punishment and that dislike of aggressiveness seems to be part of the reason why.