Decline of rodent populations in John Calhoun colony experiments was marked by increase in violent acts. Tit for tat behaviour is generationally unstable in overcrowded stressed environments. Human instincts and generational media learned behaviour are not so different, as each generation adds increments of hostile behaviour and more stress to child rearing, and sensory social environment becomes poorer. Behaviour, environment diminish, while violent competition increases in causative positive feedback. Eventually entire populations stop breeding. No surprise that practises such as Feng Shui may work as an overcrowd civilization cultural protection measure for harmonisation, such things badly lacking in commercial USA cultures. Shopping malls a total design failure.