history-society

Damon Centola's experiments upended a core assumption of network theory: for behaviors that require social proof, dense clustered networks spread change faster than loose viral ones. Simple contagions behave like viruses; complex ones behave like norms.

Your health is influenced by your friends' friends' friends. Christakis's network studies showed that social contagion operates over longer chains than anyone suspected, with implications for public health, political behavior, and how we think about individual choice.

You didn't reason your way to most of your opinions — you caught them. Research in social contagion shows that beliefs spread through networks via exposure and reinforcement, following epidemiological patterns that have nothing to do with logic or evidence.

The mathematics of infectious disease maps almost perfectly onto the spread of ideas, emotions, and behaviors through social networks. Network contagion theory gives you the tools to understand — and sometimes predict — how cultural change actually propagates.

Collapse isn't random. Turchin's structural-demographic model finds the same variables repeating across Roman, Chinese, and European collapses. When you run the model on current data, the output deserves serious attention.

Rome fell over centuries; the Maya collapse was regional and partial; Byzantium lasted a millennium after Rome's fall. Case-studying all three dismantles the myth of a single collapse template.