"Adam Smith thought imitation reflected your understanding of another person's experience—your body shows what you think another person feels. In fact, the reverse is also true: you feel what your body shows. When you see a pained expression on a friend's face, your face may also contort into a pained expression, thereby making you feel a touch of pain yourself. Sit up straight and you'll feel more proud of your accomplishments. Smile and you will feel happier. Even furrowing your brow, as if you are thinking harder, can lead you to actually think harder. This link from imitating another person's actions to experiencing the other person's emotions is a critical link for understanding the minds of others. If a researcher disables your ability to imitate another's facial expression, such as by asking you to hold a pen pursed between your lips or by injecting your face with Botox, your ability to understand what another person is feeling drops significantly. Botox dulls your social senses right along with your wrinkles." Nicholas Epley