Feelings are emotions that are separate from will or knowledge. They are evoked by any mental or physical activity and cause a person to feel good or bad about any given thing. Generally, one experiences feelings of pleasure and displeasure in connection with sensations. For example, it is the sensing that the fur emits warmth that is the feeling. One may call this reaction to the sensation of touch a feeling. The word feeling is sometimes used to describe the total consciousness of a number of separate physical sensations, such as a feeling of good health or a feeling of drowsiness. Feelings can at times be projected, allowing a person to sense how someone else thinks or feels. Even though one has no direct knowledge of the frame of mind of others, one can often guess quite accurately how someone else feels or thinks. Projection is a form of empathy. Many psychologists believe that emotions are learned and that infants are born without emotions. They believe that a growing child not only learns his emotions but learns how to act in certain situations because of an emotion. For example when a child first meets a snarling dog, the child may have no emotion toward the dog. If the dog tries to bite the child, he develops fear toward the dog. Because of the fear that the child learned, he avoids snarling dogs in the future. Psychologists think that there are two types of emotions: positive emotions and negative emotions. Positive emotions include live, liking, joy, delight, and hope. They are aroused by something that appeals to a person. Negative emotions make a person unhappy or dissatisfied. they include anger, fear, despair, sadness, and disgust. Emotions trigger chemical and physical changes in the body that often help to protect it against danger.