Everyone Says So

“Everyone says so” feels like evidence. If so many people believe something, surely they have reason. Sometimes they do. But popularity is a weak sign, because people often believe a claim simply because others around them do.

Crowds can share a mistake. A rumor passes from person to person, each one adding weight by repeating it. A thousand people repeating one weak source are no better than that one source.

The useful question is not how many believe it, but what they are basing it on. If many people have checked independently, that counts. If they are all echoing one another, it does not.

The best pizza

A new pizza place has a sign: “Voted best in town, everyone says so!” Ravi asks who voted. The owner says it was a poll on his own social page, open to his customers.

Ravi learns that the crowd was a group of regulars, and the vote was never compared with other places. He still tries the pizza, but he does not take the sign as proof.

Try this today Next time you hear “everyone knows,” ask once: what is that based on?

More on this fallacy: Bandwagon →