... as MF points out, it doesn't seem to happen in real life disasters. Could it be that people band together, cooperate, and assist one another?
Yes, at least according to Rebecca Solnit. And the effect lasts about 6 week.
http://www.washingtonpost.com/wp-dyn/content/article/2009/08/21/AR2009082101111.htmlAnd no, that effect does not exclude looting or robbing from happening. Neither does it exclude people from being ill tempered, sleep deprived, full of anxiety or aggressive.