TL;DR

This video dives into the famous “six degrees of separation” by running network simulations that show how just a handful of shortcuts and “weak ties” turn vast social webs into surprisingly small worlds. You’ll see how small-world models, hubs and even game-theory puzzles like the Prisoner’s Dilemma reveal the hidden math behind how quickly you can really reach anyone (or how fast a disease can spread).

Along the way, Veritasium unpacks Duncan Watts’ small-world ideas, Steve Strogatz’s clear storytelling and Barabási’s “rich get richer” hub theory. It’s a fun, interactive trip through network science—complete with simulations, real-world examples and the reminder that your own choices can ripple out and change the whole system.

Watch on YouTube