Hey KZ,
In my case, my father was the N (professionally diagnosed 2x) and my mother was the co-D …. until he died.
Once he died, it was almost as if she no longer had a personality of her own, and became him, or she was his mini-me all along – and just hid it better.
In retrospect, when I think about what she did to me as a child, I am thinking the latter.
Funny you asked about descent.
My Nona (my father's mother) was of Sicilian descent.
I loved her.
My father/mother hated her.
I don’t know if she was playing games, but she was the
only one in my family who ever cared about how I felt and what I was going through.
She was the only anchor I had.
My mother, as well as, grandfathers on the maternal and fraternal side, were primarily of Germanic descent.
Truth be told I am a mutt

(French, German, Italian, Scottish, English, Scots Irish…).
Personally, I don’t like to pinpoint to an entire race; however, I don’t doubt you have a valid point here – it would be an interesting study.
It has been my experience that descendants of those of the “romance” languages (myself included) are more prone towards emotion and fighting rather than discussion. That is what I grew up with. It was always a fight, and a loud one at that.
I just don’t feel comfortable putting it down to a “race” per se.
I think it takes a lot of factors to make an N, both genetic and environmental.
I do think this would be a great study – a study of the romance languages to determine if this impacts development into a personality disorder.
(On edit, I had a Spanish teacher in college, and she pointed out that it was interesting how some information translates from English to Spanish … She said that in English, one would say, “I dropped the pen;” whereas in Spanish, one would say, “the pen fell from my hand.” At the time, I thought about ownership of what we do, and wondered how much language influences what we think about ourselves and those around us?)
You have me thinking!
Blessings to you,
Peace