Mal­colm Glad­well inter­viewed in The Inde­pen­dent: “‘One day, I’ll write a really nerdy book’… but until then, Mal­colm Glad­well will be the rock star of non-fiction. As he embarks on a British tour, the author talks to David Usborne about plane crashes, Gor­don Brown – and why Obama’s elec­tion was a true tip­ping point”