So are all humans "hard-wired" in exactly, precisely the same way?
See? They'd have to be in order for your ideas of objective morality to be true.
Baron Max
First, they are not all hard-wired the same way. Second, for morality to be objective, they would not all have to be hard-wired the same way.
What it might all mean is that morality is like a scale from 1-to-10, and where each individual is on the scale might depend on the size of a certain gland, or something else of that nature. The fact that so many serial killers and unapologetic murderers share this trait speaks to this point very clearly.