I think that the nature vs. nuture argument is one that may never be resolved, despite the best efforts of sociologists and psychiatrists over many years. Personally, I think that there is a fundamental part of us that leans one way or another. I can remember one of my earliest "bdsm" experiences was playing a game with an older friend and having to strip naked as a forfeit when I lost. I distinctly recall my sense of excitement at the vulnerability and humiliation I suffered, and looking back now after many years I can definitely see my submissive nature in that younger version of me.

This was all long before I had any real interest in sex, and certainly before I knew of the existence of anything like BDSM.
This theme would continue into my teenage years, with lots of solo play and one relationship with a male friend that involved me playing the part of a submissive sexual victim. Even when I began regular dating and relationships with girls, this side of my personality always lurked in the background, kept very secret, but it had been present for a long, long time, and remains to this day.