Jealousy is the emotion of mate guarding, paying attention to the behavior of our mates around others. There are many evolutionary reasons for this, and Dr. Geoffrey Miller explains why a little jealousy can be good. Also, be honest with yourself about why you are in a relationship. Tucker Max and Nils Parker give advice on mate value in different life stages. And Tucker runs through 5 quick questions to ask yourself to understand if a relationship is going to last or if she will eventually look for and find someone else.