S1·E57 Why do We Fall in Love?

When we're really in love, all hell breaks loose. The heart races, palms sweat, the mouth goes dry and the brain switches to "happily insane" mode. Some cultures are convinced that that's not a solid foundation to build a marriage and family on, opting for arranged partnerships instead. But romantic love evolved for a reason. If we loved each other in small groups, then males would know who they were related to, and would fight for them and their children.