Stand at a street corner and look up at nothing. Just stare at the empty sky. Within a minute, strangers will stop and look up too. At nothing. Because if others are doing it, there must be something to see.
Researchers actually ran this. One person looking up — most walk past. But add a few people gazing at the same empty spot, and passersby stop, crane their necks, and search a sky with nothing in it. They don't ask why. They assume: if people are looking, there's something to see.
This is social proof, and it runs deeper than you'd like to admit. When we're unsure, we don't reason our way to an answer — we copy the crowd. It's an ancient shortcut: if everyone's running, run first, ask later. Usually efficient. Occasionally, it walks you straight off a cliff together.
Here's the unsettling version. In an emergency, a room full of people can make you less likely to get help — the "bystander effect." Everyone stays calm because everyone else is calm, each person reading the others' stillness as proof there's no danger. The crowd talks itself into doing nothing. People have collapsed in busy places while dozens stepped around them, each assuming someone else had it handled.
People looking up doesn't mean there's anything in the sky. Everyone staying silent doesn't mean nothing's wrong. The number of people believing something tells you how contagious it is — not how true it is.