At least in the enlightenment period, tend to come from political philosophy rather than history... though the two are closely related in this period. Notably, Hobbes and his "state of nature" concept.
Philosophy of this period (also Locke, Marx, etc) tended to speculate about the past using reason, rather than empirically. A lot of their ideas have been passed down to us.
Hobbes' saw life in the "natural" state "solitary, poore, nasty, brutish, and short." Eventually government arises, using its monopoly of violence to end day-to-day violence, cheating and such.
I don't think the original writers are compelling anymore, but they are hard to shake entirely. Memes die hard.
In any case, I think the reality of people at all times is that cooperation is a fundamental. There are no societies without cooperation, some form of solidarity, love, etc. We could have never survived without it. Violence is also common in history, but we don't need it to survive. We also know that primates, dogs and other creatures have demonstrably empathetic behaviours, a sense of fairness and such.
As I implied at the start, I think the mistake is literal fundamentalism. Human behaviour can't be logically derived from a fundamental nature.