As I most write historical fiction, where most of my characters come with names pre-assigned, this thread would seem irrelevant to me at first brush. And yet...
Maybe it's not.
Much has been written about how people are impacted by the names that their parents give them. And when you know little about a character besides their name, that serves as an excellent starting point to delve into their personality.
Case in point: I have a protagonist with the name Kätie Otersdorf.
First off, those little dots over the "a" mean that her name suggests both the English word "cat" and the German word for same, "katze." And yes, she is reliably "catty" in her behavior and moods. The image of a stray cat in particular comes to mind; men would like to tame her, and think they can do so by kind words and petting. In the right mood, she encourages this; but then will suddenly change her mind and become aloof. Just like a cat, she serves no master, needs no keeper, and is capable of taking care of herself. She does seek intimacy, if only skittishly, and on her own terms.
Then, there's the last name: Otersdorf. Frumpy and dour, that is. She got it from her father, whom she openly despises, and whom we are told is an odious, evil, powerful, scheming bureaucrat. The fact that her last name isn't exactly "pretty" also jives with her self image. Katie is not unattractive, but she is not a natural beauty either. Her perception is that she has to work harder than other, more naturally graceful girls, to project attractiveness. Sometimes she bothers, sometimes she doesn't. That fact that men come on to her anyway, she ascribes to their lecherousness and low standards, not her own physical beauty.
It is also true however that a person's real persona is reflected in what alternate names people call them. I would submit that most of us have multiple names--and corresponding identities that go along with them.
There's the official one on our ID card, which we may or may not use, but probably carries the full baggage of our childhood because that is what your teacher read aloud during roll-call; there may be a professional title by which we are addressed in a work setting, which we associate with our responsibilities and obligations; then there are the various nicknames given to us by friends of varying levels or intimacy, family members, and loved ones. Add to that, whatever your children happen to call you if you are a parent. My point is, when writing a real-life character, you can deliberately use all those variations to shape how they are presented, how they perceive themselves, or how other characters perceive them. And all that can (and probably should) vary from scene-to-scene.
Going back to Kätie, here is what I have other people call her:
She is "Kat" to men who desire some intimacy with her (trying to tame the alley cat)
She is "Nurse Katie" to her patients.
She is "Sister Katie" to her fellow nurses (to her face)
She is "Böse Kätie" (Nasty Katie), or "Herr General" to her fellow nurses (behind her back)
She is "Nurse Otersdorf" or "Miss Otersdorf" to her superiors, who mostly view her as a challenging HR problem to be solved.
The only people that actually call her "Kätie" are her best friend, and her eventual lover (the co-protagonist of the series). The latter, however, only calls her by that name after a long period of awkwardly clinging to the more formal "Miss Otersdorf," which itself reflects his reluctance to acknowledge any intimacy with a woman who frequently and publicly challenges his authority.
I could go on, but I think I you get the point. Sorry for the long post, by the way, but I got up early (on my side of the pond) and have already drank ALOT of coffee. Have a nice weekend!