A family is a dictatorship ruled over by its sickest member

The line that's the best definition of family I've ever heard.

“A family is a dictatorship ruled over by its sickest member.”

I think about this line all the time. First time I encountered it was in Act One, the autobiography by playwright Moss Hart:

I cannot remember who it was who said that a family was a dictatorship ruled over by its sickest member–he certainly could not have known my grandfather–but it was some…