The pro­vid­ed con­tent appears to be a brief sec­tion of a book, specif­i­cal­ly a table of con­tents or intro­duc­tion list­ing oth­er works by Mal­colm Glad­well. It does not con­tain suf­fi­cient nar­ra­tive text or details for sum­ma­riza­tion as per your require­ments. Could you please pro­vide a dif­fer­ent sec­tion of the book that con­tains more con­tent to sum­ma­rize?