“Love is a lot like air. It may be hard to see, but it’s in you and all around you.” Psychologist Rick Hanson, PhD isn’t pulling this idea out of thin air. Many scientists believe that love, defined broadly, has been the primary driving force behind the evolution of the brain. Groups of early humans who were skilled at understanding and caring for each other outcompeted less cooperative and loving groups. They lived to pass on genes of empathy, bonding, friendship, altruism, romance, compassion, and kindness. Love is in your DNA.