This is a linkpost for https://thewaywardaxolotl.blogspot.com/2017/05/ideology-and-violence.html
This seems like a story that's unsupported by any evidence, and no better than fiction.
They could have fought over resources in a scramble of each against all, but anarchy isn't stable.
This seems most likely, and "stable" isn't a filter in this situation - 1/3 of the population will die, nothing is stable. It wouldn't really be "each against all", but "small (usually family) coalitions against some of the other small-ish coalitions". The optimal size of coalition will be dependend on a lot of factors, including ease of defection and strength of non-economic bonds between members.
This seems like a story that's unsupported by any evidence, and no better than fiction.
Not at all. It's just a description of the island's population over time, followed by a logical conclusion of what most likely happened when the ecosystem becomes overpopulated. Without sufficient famine, disease, or predation to cull the population back below the carrying capacity, and without new crops, technologies, or resources to satisfy the population, the inevitable outcome is conflict over resources. Which sentences are "unsupported" in your opinion?
The ecocide hypothesis is not a minority position either. There is criticism against it, but we also know that there's a strong and general humanist academic bias to oppose it in general.
It wouldn't really be "each against all", but "small (usually family) coalitions against some of the other small-ish coalitions".
I think this is pedantic, but I understand what you meant. Parents would compete against other parents to feed their starving children, and siblings may compete against their siblings to some extent and others for care and resources. Coalitions could form to attack other coalitions, but the possibility of defection or betrayal effectively turns the competition for survival into each against all.
Specifically, "So, the islanders split into two groups and went to war." is fiction - there's no evidence, and it doesn't seem particularly likely.
Thanks for commenting. However, he also wrote in the same paragraph:
There are no written records of it, but I'm pretty sure that's what happened, or something like that.
He wrote "or something like that", so I think that allows some variation of two (main) groups fighting each other in a war. He gave his reasoning for why individuals would team into larger groups in the previous paragraph, but I will agree that it's mostly speculative how many warring groups there were. Regardless, I'm convinced that the island's environmental degradation and population collapse were both most likely caused by overpopulation.
"something like that" isn't open enough. "or something else entirely" seems more likely than "something like that". Many more than 2 groups (family-sized coalitions) is an obvious possibility, but there are plenty of other strategies used by primitive malthusian societies - infanticide being a big one, and ritual killings being another. According to Wikipedia, Jared Diamond suggests cannibalism for Rapa Nui.
Looking at Wikipedia (which I should have done earlier), there's very little evidence for what specific things changed during the collapse.
In any case, it's tenuous enough that one shouldn't take any lessons or update your models based on this.
The audio version can be listened to here:
I often use the term "ideology", so I thought I should explain what I mean by it. The Wikipedia definition is:
A comprehensive set of normative beliefs, conscious and unconscious ideas, that an individual, group or society has.
I use the term in a more specific way. My definition is:
A system of ideas that defines a social and moral dichotomy between US and THEM, GOOD and EVIL.
In this essay I will expand on my definition of "ideology". I will explain the function of ideologies and how their form derives from their function.
I will start with my favorite example of group conflict, Easter Island. I have described what happened there before: population explosion followed by collapse.
Imagine Easter Island just before the collapse. Let's say there were about 5,000 adults and 10,000 children living on the island. The children were growing up and eating more and more food. Teenagers eat a lot. The island could only support about 10,000 adults. There was no conceivable way to expand food production on the already overcrowded and environmentally degraded island. In fact, food production was starting to decline. There was no way to escape from the island, because there were no big trees left to build canoes from, and even if there were, there was no way for everyone to escape from the island. There was no way to get off, and nowhere to go if they could.
Easter Island is a very good analogy to the situation of the entire world today. I think we are getting close to the peak of global food production and population. I don't know that it will happen in this generation, but it will happen soon.
Back to Easter Island. For many generations before the collapse, the islanders were able to expand food production to keep up with population growth, Then, in a single generation, they suddenly went from abundance to scarcity. There simply wasn't enough food to go around, and as existing children grew up, they needed more food. The stark reality was that at least 5,000 people had to die.
What were their options? Well, they could have drawn lots to decide who would live and who would die, but that isn't the sort of thing that people are willing to do. (For a good reason: it is a terrible reproductive strategy.) They could have fought over resources in a scramble of each against all, but anarchy isn't stable. Why? Well, because if two people form a cooperative unit, they can defeat almost any individual. If three people gang up, they can defeat almost any pair, and so on. The most effective strategy for an individual is to join a social unit that is big enough to defeat rival groups, but smaller than the entire population.
So, the islanders split into two groups and went to war. There are no written records of it, but I'm pretty sure that's what happened, or something like that. Previously, they were all part of one society that lived in (relatively) peaceful cooperation. Perhaps there was some competition between men over women, but there was no large scale, genocidal warfare. Once they reached the limit of food production, however, the only feasible strategy for survival was to be on the winning side of a genocidal war.
(see the rest of the post in the link)