Do you think of happiness as a limited resource? That is arguably the implicit, if illogical, feeling underlying emotions like jealousy, envy and schadenfreude—that one person’s luck comes at the expense of your own. 

An envious worldview frames the positive stuff in life as a finite pool that can be depleted, much like money, which capitalism has bound tightly to notions of satisfaction. When you see someone else’s good fortune through jealous eyes, you want it too; when they suffer, you might feel they have been brought down closer to your level. This scarcity mindset can make it difficult to be happy for a friend when they are offered a new job, jet off on vacation or land a gorgeous new partner. 

Of course, happiness is not the same as money: There should be more than eno...