[Eli_P]

It's hard to understand how family as an abstract entity can be happy. If we don't have some metric of happiness for one, how can we add it up?

If abstract happiness existed it would be incomprehensible, like consciousness in China brain[1] thought experiment. Or such happiness would be observable for all but this particular family, i.e. show-off happiness. The latter is a punchline in Dostoevsky books.

[1] https://en.wikipedia.org/wiki/China_brain

[deepsun]

Family psychologists have a metric - divorce

[carapace]

I'm not sure what you're saying, but I would point out that there is no such thing as an abstract family. Families are real living organisms.

[Eli_P]

I mean family is a structure built on top of real human beings. Social structures are real while everybody trusts in them, same as how any belief system works, money, etc. Even the definitions of family are different in various cultures.

What it means in real life, the happiness of family is not a sum of everyone's, but some sort of compromise.

[carapace]

It's complex and unquantifiable, I agree.