You arrive at a party at an unfamiliar home. As you ring the bell, you rehearse the next few moments — explaining who you know, why you’re there, where you’ll place the bottle of wine you’re holding. Then the door opens, the hellos begin, and suddenly, there’s a powerful distraction. Out of the corner of your eye, you spot a pile of shoes in the entranceway — heels, dress shoes, boots. Immediately, your mind drops everything else, and now your most important task is pulling off your shoes before you take another step on your hosts’ immaculate floor. No words are exchanged. You know what to do, because everyone else is doing it.
That’s social proof.
When people are in unfamiliar circumstances, they naturally look around them for cues on how to act. If you attend a wedding or a funeral involving families of a new culture, you try to lay low and blend in. When you get a new job, you observe when people take breaks, or what the etiquette is for coffee runs.