 In the lower animals, mental processing is not abstract but tied to present experience, needs, and opportunities. It is about nearby predators, food, mates, etc. When something violates their expectations, especially something involving a potential or actual loss, their typical reaction is fear, anger, disgust, or sadness. These emotions evolved in mammals and were useful for millions of years because they motivate adaptive behavior such as fighting, fleeing, avoiding noxious substances, withdrawing from activity, and avoiding similar situations in the future.