For more on sociopathy, check out "The Sociopath Next Door": http://www.amazon.com/Sociopath-Next-Door-Martha-Stout/dp/07...

I found the book, _The_Sociopath_Next_Door_[1], to be an interesting read. The premise of that text is that 4% of the population has no conscience. Moral obligations probably can't be explained unless you go to the meta-level and talk about neuro-chemistry and evolved behavior of social animals. Kind of like trying to explain romantic pair-bonding, or parent-child love, or religious devotion. Unless you have those experiences, you really are at a loss to explain how or what it is. I suppose it is similar to trying to explain the concept of "red" to a person who was blind from birth. You can talk about wavelengths of electromagnetic radiation, but it just doesn't seem to capture the gut-level feel for what "red" is. Sociopaths probably don't get the same bursts of endorphins that the rest of the population gets from performing socially important acts.

[1] http://www.amazon.com/Sociopath-Next-Door-Martha-Stout/dp/07...