Martin Amis: 'We can’t pretend that something hasn’t gone a bit wrong with English culture in the last 50 or 60 years. One can make a laborious historical case for saying it’s to do with national decline; once you lose real power in the world you become fixated on trivialities and surfaces and superficiality. And I think that has happened. I don’t think there’s another nation that’s so interested in people who are not very interesting.'