Social proofing is when we make decisions by what we see other doing, under the assumption that this is the safe and correct choice. We assume that other’s decisions are going to be more accurate than our own, and will guide us to make the right choices.
Social proof is part of how we are as people. Look at history. If lots of people drank from the same well, the water was considered safe. If groups of people were eating fruit from the same tree, the conclusion was that it wasn’t going to make us sick. We can see examples of social proofing all around us. We can’t wait to try out a new restaurant of an already acclaimed chef; we’re more comfortable with fashion trends because we see them on other people; and no doubt, there are plenty of us carrying the same phone in our pockets.