in some ways less true that saying we share culture with Canada, Australia or even USA which is more that just language, to do with legal and political systems and history.
Having spent time in the USA, I don’t think we share much with them beyond popular culture. And if you look closely even that reveals the huge cultural gulf between us.
I feel we share far more with our immediate European neighbours than with Americans.
Re that book, I have not read Guns Germs and Steel but I have read about 2/3 of Collapse by the same author. Turns out that being told something quite obvious over and over again extremely slowly isn’t my cup of tea 🙂