Memoirs and Biography on New York Times Nonfiction Best Seller List

I was struck by the April 17, 2011 Nonfiction Best Seller List from the New York Times. I know that it is only April 14 as I write, but the newspaper has a crystal ball approach to the list. It isn't really the date that jumps out but its titles. This is what I see:

• 9 memoirs
• 3 biographies
• 1 history book
• 1 science book
• 1 sociology book

The history book is Sarah Vowell's Unfamiliar Fishes, which is about Hawaii but probably has a lot about Vowell in it as well. You could say that 13 of 15 books on the list are biographical. I don't I have ever seen a list quite like it.