I watched one of those survival programs based on stone age life. What struck me was that in the program the lazy , self centred and workshy ones seemed to survive better than those who worked hard finding food etc. They worked themselves to the bone while the others nicked the food and lay about conserving energy. I guess in the real stone age those tossers would have been tossed out of the tribe. Anyway, so any system has to account for negative traits of humans as well and there will always be some who try to exploit the system for personal gain.