Donald Trump (post 12) seems unable to “pivot”: If he has multiple personality, he might be less flexible than a person with one multifaceted personality.

If a person with multiple personality were like a group of people, he might find it easy to “pivot”—change tactics in a political campaign—by just switching to one of his other personalities.

But a person with multiple personality is not like a group of ten people. He is like one person divided into ten parts, with each part specialized to come out and deal with a particular type of situation. And if one of those parts is specialized in personal confrontations, then that is the part who will take charge in debates.