Well i allready said i doubt the genetics but Wiscoman stated that thing about being in the middle of evolution.
Well thats true but evolution in the darwinistic sense meens change happens over noumerous generations. Thus evolving from sub parents to hypercontrolling dom, is a contradiction of evolution and genetics as an explanation.

Studying people i have noticed that some tend towards submissive behavior in all or most aspects of life. Following leaders, experts and dominant features. Clearly this is a survival strategy of sorts, keep your head down and people are more likely to accept your shortcommings.

But humans are born with way underdeveloped intellect and hardly any skills compared to most other spiecies. With brains developing untill age 22 or so and sexual maturety pretty late in this development.

An indication that people can indeed have their sexual preferences imprinted on them would be how phobias work. A common statement on phobias is that alot of american skyscrapers were built by prarie indians. Why? because having never been to tall places before a pretty late age theyr not afraid of heights (well thats how it was back in the day). Most studies on phobias claims they stem from learning emotional responses from parents (moms mainly as i recall it) So if your with your mom at an early age and she has what you interpit as a fearful reaction to spiders, height og whatever. Youll pick up that reaction because since she reacted so strongly its obviusly important to your survival.

Well if thats how phobias work, why wouldnt a more complex form of the same be true for surviving in the community, part of that being relationships. That is seing a strategy (like submitting) and considering it succesfull perhaps at a wery early age is all it takes. Sometimes seing a strategy fail will have you do the opposite later on either taking inspiration from the "winning" side or simply learning that that didnt work same way as we learn lots of other things.

I dont have final answers, but i highly doubt genetics as that would indicate the possibility of breeding dominance or submission into a population same way as youd breed horses. History has multiple examples of societies with class based mating and severe punishment for attempting to go above ones class. Thus favoring submission in the lower classes and dominance in the higher. Really that didnt leed to a submissive lower class in europe not permanently so atleast, plenty of other features could have been bred into europeans during that time. Atleast going by how many generations horse or dog breeding takes.

As for the sometimes wer sub sometimes dom perspective. True but taking on roles and setting aside our nature is pretty much how we became a dominant species on earth. That does not imply that we cant have a basic nature that we fall back on when relaxed. Personally id say we have varying degrees of dom or sub personality, possibly mainly one of the two but rarely exclusively.