In my Social Psychology class this week we've been talking about aggression in humans, and being a social psych class, we've been looking at societal causes, cues, ramifications, all that.
Today we talked about a social psychologist, in the 60's, I believe who did an experiment on rats to study aggression in their societies and see if there were any useful parallels to human society.
People don't typically know that rats have very structured norms of behavior and have little miniature socieities. For instance, if a female rat is interested in mating with a male rat, she wiggles her ears at him, and that's his cue to respond. Typically the male rats honor this code, and if a female doesn't wiggle her ears, he leaves her alone. They also have hierarchical social structures (I guess like bees and aunts).
So this guy, John Calhoun, decides he's going to get a bunch of rats and build an enormous cage, about the size of a small house, and completely manipulate their environment so that everything is ideal, and just stand back and watch what happens. The results weren't pretty.
First off, since they were in a cage, they were totally safe from predators; no worry about them. It was climate-controlled. There was never a lack of food or water. They had everything that happy little rats could possibly want.
It started out nice enough. They ran around and did their thing, and ate and drank and slept. And bred. And bred. And bred. All they did was breed, until the cage became full of rats. And that's when the fun started, and all the rules of their societies began breaking down.
Disease ran rampant.
Male rats started becoming very aggressive toward female rats, and believe it or not, started engaging in gang rapes of females. Sometimes to the point of death for the female. Think about that for a minute.
There started being a sub-group of very anti-social rats called "floater rats," who spent all of their time alone (very unusual for social rats), usually sleeping, and only came out to eat at night when most of the other rats were sleeping. As a consequence, they were very lethargic and became extremely obese and starting dying off.
Maternal instincts broke down, and mommy rats began abandoning their baby rats, some of which were products of rape by the male rats, and the rat infant mortality rate became very high. And those baby rats that were abandoned and lived usually became very anti-social and aggressive toward the other rats as well.
In other words, the crowding, the (eventually) unsanitary conditions, and the lack of any real predators (aside from the rats themselves) led to a complete breakdown in the rat society that eventually devolved into complete chaos.
Take from this what you will.