It’s no secret that human beings base much of our judgments on looks. How a person looks is usually the first thing we notice about them, but what happens if you meet someone without seeing them?

It takes just seven seconds to build a prejudice based on someone’s appearance. Clothing and posture are the biggest factors people use to judge another person upon first meeting. Are you someone to approach or to avoid? Are you friend or foe? Do you have status and authority? Are you trustworthy, competent, likable, confident, and so on.

Allowing these strangers to meet in the dark meant that they had to use something besides appearance to form a first impression.

However, in this campaign ad run by Coca-Cola, the ‘seeing’ part is missing. They invited six strangers to sit in a dark room together. One-by-one, they share their stories with each other. When the lights come on, they are astonished. Their reactions are proof that “judging a book by its cover” is never a good idea.