Society has started down a slippery slope to the bottom when it comes to sexuality. When you look at the 60's, then the 70's, 80's, and so on, each generation is doing nothing more than trying to shock and go a little further, which is further to the bottom. No generation of teenagers is going to suddenly decide to be more modest or more chaste. Sex sells, and we become numb to it so we have to push the envelope.
Yes, I believe that humanity is in a sexual race to the bottom, because the sexual practices of today were unheard of years ago. Even 50 years ago, teenagers were not handed condoms and told to have at it. 50 years ago, abortion was not seen as a method of birth control. Fathers were not allowed to be rappers instead of parents.
Humans have always been sexual beings, and not always in the context of monogamous heterosexual marriage. For example pornography has been around since people could paint on caves. Sexual "toys" have also been around for a long time: scientists discovered a phallus that was over 28,000 years old. With the advent of sexting and other methods of "cyber-sex" there are different ways to express the human sex drive, but its existence is pretty much unchanged.
It is my opinion that humanity is not in a sexual race to the bottom. I feel that sex has been a controversial topic for many years, and that there have always been those that are deemed depraved by their peers. I do not feel that there is any more depravity in the world in regards to sex than there always has been.
First of all, this question makes no sense. Why would a race be to the bottom? Wouldn't the 'top' be a metaphor for the 'best'? Humanity is not a sexual race to the bottom. If it were, we would all be walking around wearing our underpants on our heads, or slurping our own fluids.