Building on previous research concerning murder and suicide, this study investigates 18 forms of aggression and explores how they might be engendered by certain child-training practices. Results show a weak connection between most forms of aggression and child-training practices, but non-literate societies do show a positive correlation between murder and suicide. The author develops a theory positing that experience of social blockage will be related to outwardly-directed aggression, whereas social loss will be related to inwardly-directed aggression.

This paper tests assumptions regarding the inverse relationship between murder and suicide. Analysis suggests that murder and suicide in fact vary together, and they are also positively associated with overall punishment in a society.