EmpiricalRequires evidence

There is a hard ceiling on coordination by acquaintance, and the mechanism is combinatorial. As a social group grows, the number and complexity of interpersonal relationships each member must track to keep the group healthy rises exponentially, so past a point groups collapse under their own size and split in two along factional lines. Part I puts the maximum group size for homo sapiens that can be supported by intimate relationships at about 150 individuals. Everything above that number, the company of ten thousand, the nation of a hundred million, the supply chain of several thousand strangers, is held together by something other than acquaintance, and the rest of the chapter is about what.

Coordination architecture