I'm indigenous from northern Ontario. My parents were born and raised in the wilderness and the first ten years of my life were partly spent on or near the wilderness.

Yes people do help one another in times of need .... but only if the people helping have a surplus to share. But when people are on their own without outside resources, food quickly becomes scarce.

My parents and elders told me lots of stories of famine in the wilderness in the 40s and 50s. When everyone is hungry and everyone is facing death ... people start doing some ugly things to one another ... murder, sabotage, lying, cheating, stealing, abandoning children and just plain letting people die. Being an orphan back then was a death sentence for children. The elderly were on their own and just expected to die when they no longer could keep up.

And that is just a thousands of years old traditional culture living in their normal environment.

I can't imagine what would happen to people living today if they suddenly had to face death, starvation and extreme poverty. The first hundred years would be a huge adjustment for humanity and after that I expect the survivors to be more like the hunter gatherers of North America like my ancestors ... or those of ancient Europe.