Not necessarily. Once, when X was the given letter, and Le Ministre was hosting, I asked an IQ about Francis X. Bushman. There was some discussion about whether middle initials were included, and Le Ministre answered as follows (you can follow the link in the quote):
So, it looks like middle initials are fair game; though perhaps we ought to allow DQs such as “Does X begin your first, middle, or last name?”
There are individuals, fictional and non fictional, who are little-known by their first names, while their middle names are better known. A few examples would include J. Edgar Hoover, F. Scott Fitzgerald, J. Fenimore Cooper, and the fictional J. Alfred Prufrock.
And what do you do about people known by all three names? The kids from the “Home Improvement” TV show come to mind: Zachary Ty Bryan, Jonathan Taylor Thomas, and Taran Noah Smith. And then there is the fictional character Miranda Veracruz de la Hoya Cardenal, from “Married with Children.” I’m unsure how we’d go with that one–but I’m sure we’d narrow it down somehow.
It would seem to me that middle names are fine, as long as DQs can be expanded to allow for a “first, middle, last?” question. Thoughts, anybody?