I disagree with you on many of those accounts.
First of all, most animal species aren't at all as you describe them. Some female spider species eat the males after breeding, most lion species, the females do all the hunting, some cat species are totally solitary except for that short span in which they copulate, some wolf species it is the community that counts, some fish species it is the male who protects the young... Nature is varied...
As for free thinking... I still doubt that. I see our own free thinking as being as evolved as that of most other species. As for expanding borders in conflict with their environment, you should look no further than the canadian beaver who floods areas and brings down live trees for housing.
The belief of having to own things is as simple as the birds and the bees. Some bird species, the males build impressive houses only to attract females, some collect oddities to do the same, and wolves prove their strength to become the leaders and get all the females without having to hunt. The American Way Of Life only pushed this even further as creating that need in us. Or do you believe that this need actually comes from "free thinking", and that we do this without any prior explanation? Or is it really that same need to own things as ôhe need for the wolf leader to be the strongest?
I believe all interest must spawn from a desire that was created at some point, be it consciously or subconsciously, known or unknown... I for one am not sure about my own reasoning behind my interest, but I do have some clues and may someday find out with more introspection.
In otherwords, I say people get in to it because of some relating, positive experience and connect that with the general concept of BDSM. This follows that they try it again to get that positive experience again and then get even more relating positive experiences which then create a need...
This rule not only applies to the subject at hand, but also with your first sexual experience, first pay check, or even, horrors of horrors, getting praise for the accomplishment of an evil deed. Psychological instances and nurture dictate our likes and our dislikes as that is the way our nature deems it.
Now we can ask, the chicken, or the egg? I say the chicken runs the show, but the egg came first. (Nurture runs the show, but nature came first)
Up to 8 cents. May start being worth something in a few years...
F.