No one is sure about DNA.
We just don't know yet.
You are correct about how little we know about DNA. However, scientists have found markers in DNA which may make someone more at risk for breast cancer (Angelina Jolle, for example, had hers tested and had her breasts removed based on the results).
I know they are making great strides on deciphering our DNA. There are just too many markers, in the trillions, to have mapped since scientists started in 1980's. The speed of our computers help out much more today, but there are also a lot of steps to scientifically prove or disprove each one as to what each marker does or doesn't do. And I doubt that scientist are too focused specifically on the BDSM markers at this point. They are, however, trying to prove homosexuality is linked to certain DNA markers.
As the middle child with an older brother and a younger sister, we had the exact same upbringing, however, my brother died from using heroine, he was an alcoholic; as was my father; and my sister was an alcoholic and a user of meth. I haven't used anything stronger than pot which I was 11 when I smoked my last joint. My brother started me using it at 9. I am really putting on a heavy drinking episode if I have 3 beers in one night. Why, did I not use and become addicted to drugs and alcohol as my siblings? We were raised exactly the same.
Also, I
hated getting spanked by my parents. We would try to find crap to shove down the back of our pants when we were sent to our rooms and Mom said she would be in there soon. She would notice
"Cat in the Hat" right away however, and my favorite cat could not help me. I am not sure if I would like it today, as I have not had a partner that was into my kinks and have not had the opportunity to be tested. But, again, I tested electrical shock for sexual gratification out at a young age (though I didn't know it was actually for sexual gratification, I just knew it gave me a strange sensation and I liked it) and practice it today with great enjoyment. My spankings as a child were not administered while bound, but who knows, maybe if they were I would have liked them more...I don't know. What I do know is that when Mom would take us to the grocery store, I would ask to stay out in the car, and while they were in there, I would tie myself up using the backseat seat belts. I wanted to be tied when and where there was an opportunity.
Just my feelings however. I could be wrong (been there many times) or I could be correct. Only time and scientific testing of DNA will tell.
Dana -- EPL
I don't know, as it has yet to be proven, but I believe it has to do with genetic make-up,