In my own case I would say that the first two impulses are strongest, the third was in play only in the days I wrote nonfiction pieces about comparative religion, and the fourth has always been nonexistent.
Writing, for me, is a selfish act. It has kept me from spending my hours being charitable, as is my wife, who is so charitable to me that she allows me my vanity without repercussions. For me also, there is a strong aesthetic impulse; I seem to have been placed on this earth to write. The writing habit has been with me from an early age. In the box containing some of the chief moments of my life is a letter I wrote when I was about five years old; it was to a missionary aunt, and emulated the style of her letters to our family, including a Bible verse. The next memory I have was from the seventh grade. My teacher had meted out a punishment to me and to several of my partners in some petty crime we had committed; we were to stay in after school to perform some minor chore. My aesthetic impulse came to the fore and led me to write a petition asking the teacher to rescind this punishment. It worked, and I was, for a short time, a hero to my pals.
Another of my memories is from the eighth grade, when everyone in my class was assigned to give a brief speech on the general topic How To, which led me to imagine how one goes about writing and publishing a book. I don’t recall what I said on the subject, but I can only imagine that I must have utterly misdiagnosed the efforts it takes to perform such a task.
Orwell also wrote that he liked the look of his own words on paper, and on this point he was again right on the money.