Suspicion of strangers was the human default before large-scale societies

Evidence

Alarmingly, the remaining few hunter-gatherers and foragers are on the verge of extinction. When their way of life vanishes completely, a vast store of knowledge about human origins will disappear with them. While they exist, they give us important, though imperfect, clues about human origins. While many of these groups have fluid memberships and do trade and interact with other groups under some circumstances, suspicion toward most strangers is, and has been common. But at the dawn of the Holocene, and likely starting even earlier, there has been a remarkable and sustained “scaling-up” of human groups over time. — Norenzayan, Ara, Big gods - how religion transformed…, 31

Categorization

• XREF: Anchors the premise that anonymous cooperation is the anomaly needing gods, surveillance, and partner-choice mechanisms to explain — the very mechanisms the reader is tracing through the fumi-e.