According to evolutionary theory, emotions evolved because they were helpful for survival. Anxiety alerts us to potential danger and makes us wary. Anger motivates us to fight and shows our allies that we need help. Jealousy motivates us to keep our mates to ourselves to help maximize the number of our offspring that survive to child-bearing age. But the environment we live in today is obviously very different from the environment of our distant ancestors for whom these emotions were optimized. ...