Tony Schwartz who was the ghost writer for "The Art of the Deal," and spent up to eighteen months with Trump while researching the book had this to say about him: 

"Early on, I recognized that Trump’s sense of self-worth is forever at risk. When he feels aggrieved, he reacts impulsively and defensively, constructing a self-justifying story that doesn’t depend on facts and always directs the blame to others."