How do you define happiness in the first place? Is it a bliss, joy, pleasure, an ecstatic state of mind, the satisfaction of one's desires, or the absence of them? All of the above? Perhaps none of them? Personally, I define happiness as being content with where you are right now - you wouldn't want to be in any other place, in any other time, in any other state of mind. You're happy here, right now. You have your in…
By measuring level of dopamines, and other neurotransmitters in brain when person claims to be happy. Easy and precise.