The collapse appears to be a transcendental phenomenon in the biological or social sense - human civilisation did not experience anything like that before, probably. Or do those Apocalyptic Rapture myths communicate us some bits of the picture how civilisations like ours - descendants of Babylonian and Roman "progress" cultures - tend to collapse?

Anyway, to break through the empirical transcendence, we can use logic - our brains are big, after all. Not everyone will be able or willing to use it - but hey, not everyone would adapt to any big change. If human population drops just sixfold to 1 billion, it will not even be a collapse of this civilization probably - but that would be quite an episode of real "natural selection".

Most importantly, Mad Maxs of the future have little chance. Even the ones outsmarting all others in their locality will have hard time surviving in a deserted world. To survive and live, cooperation will be a necessity. The sensible survival unit will be a community, not an individual. There lies (inevitable) opportunity for revival of morality and all nice things. In particular, the best chance for you individually to survive extreme times is to live in a moral community, and be useful there. Some people will realize this. The Holywood myth of "survival of meanest" will make little sense - some (even really smart) Newtons of survival will meet bad luck, some idiots will live through against all odds. In extreme times, you won't really think of grabbing, eating and fucking as much as possible - that would help very little. You will be just glad to find a sense of your struggle and risks while alive.