Asked by: Richard Fennell, by email
People in pain typically have lowered eyebrows, raised cheeks, tightened eyelids, an open mouth, and closed eyes. One reason is to escape from the cause of the pain. Tensing up your muscles and screwing up your face scarily might do that. Another reason is to let others know you are in pain, because you may need help. In a sociable species like humans it is important that we can read each other’s states of mind.