This could be another way of thinking about family stories, from home-schooled historian, writer, and professor Susan Wise Bauer:
Epic tales . . . display the fears and hopes of the people who tell them -- and these are central to any explanation of their behavior. Myth, as the historian John Keay says, is the 'smoke of history.' You may have to fan at it a good deal before you get a glimpse of the flame beneath; but when you see smoke, it is wisest not to pretend that it isn't there.That's on page xxvi of what promises to be an excellent read: The History of the Ancient World: From the Earliest Accounts to the Fall of Rome (New York: W. W. Norton, 2007).