Most writers, in my experience, tend to be introverts-- maybe it's easier to glue yourself to the keyboard (or the notepad and pen) if you enjoy alone time-- but one of the complexities of publishing in the modern era is how much publicity and promotion we ask authors to do in service of their book. It's part of the job, but I think it's hard for a lot of people. It would be for me!
What was your quiz result? I am "likely to be an introvert," which is the understatement of the century. What parts of the process are hardest for you?