When we look at each other, we see faces, we recognize them and we read their emotions, and thats just our memory working its magic, right? Not quite. There are two parts of the brain at play: recognition and familiarity. Its not enough to recognize a person’s physical appearance, we must also be able to connect in a familiar sense, connecting memory and appearance with emotion. When this connection is severed, our closest family can seem like imposters. Alternately, when we live in an online world where these familiar connections are absent, we lose the ability to sense imposters, and everyone seems so familiar.
– via Nautilus