The Aug. 6 New Yorker describes how biographies, like fiction, deviate from reality:
There’s no point in writing, or reading, the life of a famous person if it doesn’t uncover some previously unpublicized piece of personal information. This is because the premise of biographies is that the private can account for the public, that the subject’s accomplishments map onto his or her psychic history, and this premise is the justification for digging up the traumatic, the indefensible, and the shameful and getting it all into print. …
Biographers … invert the normal rules of evidence, on the Rosebud assumption that the real truth about a person involves the thing that is least known to others. A letter discovered in a trunk, or an entry in a personal notebook, trumps the public testimony of a hundred friends and colleagues. … Diaries and letters are the materials with which biographies are built, generally in the belief that the "real" person is the private person, and the public person is mostly a performance. …
People like the notion that a little luck is involved in success – that becoming famous could be sort of like winning the lottery. One day, you’re riding along on your donkey or in your Honda Civic or whatever, a voice speaks to you, and suddenly you are on the way to being St. Paul or Leonard Bernstein. …
Biographies of the powerful and the famous that humanize their subjects may play some kind of egalitarian social role. It’s naïve, though, to suppose that the forces driving the appetite for "critical, incisive" (that is, highly revealing) biographies are all about democracy and demystification. Secrest is more to the point: people are prurient, and they like to lap up the gossip. People also enjoy judging other people’s lives. They enjoy it excessively.
So, does fiction or biography mislead us more about reality? Real events constrain fiction less, but fictional characters rarely lobby authors to make them look good, and we expect less realism in fiction.
It seems obvious that, if you know someone's public pronouncements and also what she wrote in her diary or confided to her friends, you'll have more insight into her thinking than if you're going on public pronouncements alone (especially if the two diverge). So when I'm reading a biography, I look for the writer to combine evidence in what strikes me as a fair way: yes, dig up all the dirt, just don't harp on it to the exclusion of everything else.
There's no point in writing, or reading, the life of a famous person if it doesn't uncover some previously unpublicized piece of personal information.
That's a really, really stupid statement. I hope it made more sense in context.
Perhaps there's no point in someone who's already an expert on the famous person in question reading another biography of that person. But for that vast majority of the population looking to read their first biography of Famous Person X, there's always room for another volume that's far better written than those already available. And if it's really, really well-written, or offers valuable new analysis of the biographical information that's already public, it's probably valuable for the aforementioned experts, too.