Biographer and psychologist William Todd Schultz argues on an Oxford University Press blog that Truman Capote lied about his past because he needed to be telling a story about himself.
(If I understand correctly.)
Schultz comments:
Aren’t psychobiographers supposed to care about the facts? Yes, facts
are crucial. Facts are the instruments of revelation. I love facts. But
the reality is, remembered life is itself fiction, a constantly evolving
construction. That being so, the raw material one works with is best
approached as a “faction” — a composite of artful narrative and
quantifiable life-history. And given the unreliability of memory,
especially in someone like Capote, who saw his past as perfectible, all
one can do is dive into the messy blurriness.
"All one can do" is throw up one's hands?
With Capote, probably the answer is yes. Heck, his last novel is half-real…and half-finished. And Schultz wrote a whole book — from the reviews, a good one — about the writing of Answered Prayers.