Kindle book 37. The Price of Altruism: George Price and the Search for the Origins of Kindness.
I started reading this because I found out, I can't remember how, that George Price used to live in a flat above the deli on the corner of Great Titchfield Street and Little Titchfield Street that I walk past most days and pop in occasionally. Apparently there was a butcher there in his day. I wondered who he was, looked him up and found an absolutely fascinating character: have a read of his wikipedia entry.