Scientists found decades back that rats subjected to an ever-more-crowded home in captivity showed social changes.
First they fought more and took lousy care of the kids. Soon they killed their own kind more. Then gang rats started running from one section to the cage to another, across territories. These pubescent animals fought when they met another gang. The females watched the males tangle, then mated with the winners. When they had young they abandoned them. Some parts of the cage became rich in food and nest materials. Other parts became too poor to sustain life for long. The rich females grew a subculture that ran in small groups into the poor parts and back for no apparent reason. Males who refused to nest took food from mothers and children and moved on. A few males and females lined up along the darkest edge of the cage avoiding light. There they hung out all day and night, rarely sleeping, hardly eating, never mating or nesting, just chattering to no one in particular, grooming themselves to the point of self-harm. I used to be like that. These trends developed around the time the sexual deviance increased. Males mated with the dead, with the young, with everyone they could catch, male or female, family or not. Rape, sadism and fetishism increased drastically in the final stages. This is not typical wild rat behavior. Many females decided they had no interest in mating.
The experiment wound up with suicide and failure to thrive bringing the population down again. This study has often been held up as a warning against overpopulation. But is it really more a warning about captivity itself? Being pushed to the sides of the cage the rats can see the bars more clearly.
I have no patience at all with people who harm people and blame society. Humans have self-control in a way rodents don't.
The issue is, why are there so many people making such bad choices at so many ages just when we are supposed to have reached a safe, warm, aware stage in our culture's development? Maybe we have pushed ourselves or let someone push us right to the bars.
Those who react by hurting or killing their own kind, especially adult humans who kill children and youth, are to blame for their actions.
As for the rest of us, those struggling to make life in the cage worthwhile, how can we protect ourselves without making the cage any tighter? How can we shelter the young and the weak without shrinking our range even more?