I've heard this theory that sounds plausible. Early humans lived in such a way that the community came first, right? Hunters and gatherers don't have the means to own property or be selfish, because it would threaten the entire tribe. However, whether simply due to innovations of a group of people, or natural disaster, or competition, agriculture emerged and changed the way things worked. Now one could get all of their food from one stable place and not require the community to survive. This is how we as a species has lived for a long time since. It has bread selfishness, competition, pride, wealth, and all of that stuff that tends to be looked on negatively. It has also, however, lead to a plethora of advancements that cannot be seen as negative. But such a way cannot sustain itself forever, and somehow we are going to lose. The proposed theory suggests that when the time comes, our way of life will be destroyed and we will be thrown into a post-modern dark-ages. Not totally devoid of technology like the last one, as we have ways of preserving stuff already in place, but it will be a very tough existence. From the ashes of old civilization, bans of human survivors will have to work together in small communities for survival. Over time, this will (As it has been shown behavior could be passed down not only through example, but also biology) create a new breed of our species much like the old. Where the community comes first, where selfishness does not exist, and so on. This time around we will have the assets of the old world, and we as a species will be able to advance farther and faster than ever before, producing new forms of energy without the pressure of gaining the highest profits in the way, and so on. Think of what we would be able to do if we did not have the shadow of selfish ambition ahead of us. Of course this could all lead to a Brave New World, in which case we should all kill ourselves now.