I for one do not believe objective reality can exist. If this is the case, then all morality is subjective, therefore sociopaths arent outrageous because they have no morals. A hundred years ago gay marriage was seen as morally wrong in American society, now it is almost as if it is morally wrong to not allow it. Sociopaths are just ahead of the game and see nothing as morally wrong, including drowning children in front of decapitated parents. Maybe in a hundred years, it will be morally wrong to stigmatize socipaths. (In my own opinion, I think morality is for the weak, but again thats my opinion).
It is an adaptation for group survival. It is important for a species to survive and prosper. The morality of ants to one another (they all cooperate) is not important to humans. But the morality of humans is important to humans, because it is a successful survival tactic.
I don't believe in ethics. What we call moral and ethics is just a consensus or sometimes forced on us. It is a tool to function as a group. Nothing else. What we call moral issues are about how this group is supposed to work. There is nothing real special about ethics.
I believe there may very well be an objective reality, but for our purposes it doesn't matter because our subjective realities are the thing that shape it, if it does exist.
Morality is a construct of social organization. It is nothing more than a group of people agreeing on what is socially acceptable for them at that time and place. It is something that is maleable and constrantly reshaping itself. What was moral a hundred years ago in the middle east is not going to be the same morality we have now in america because our cultures are different. It's quite a simple concept...