Psychopathy is an inherant disorder; some people are born that way and find it hard to get a feel for right and wrong. They are very aware of their own need for gratification, though. Problems arise when this need for gratification is unchecked by any kind of self-restraint.
Sociopathy is learned behavor; sufferers learn to turn their conscience 'off' or somehow fail to learn when to apply it properly. Canadian researcher Robert Hare wrote a groundbreaking book on the subject back in 1993.
I think it is very hard to pin down how many sociopaths there are in society, since that behaviour is learned and focused narrowly on specific aspects of social experience. A person might have a reasonably healthy conscience, but be a shameless mysogynist, because that is what he or she was taught to accept as right without thinking. It is much easier to determine the number of true psychopaths, since that behaviour lends itself to consistant systems of diagnoses.
There were studies that tracked the brain activity of psychopaths, and found that they had markedly different responses to things that would cause a more normal person distress. For example, when they were given 'red flag' words, such as 'cancer', they exhibited little or no reaction, whereas a person with a conscience reacted noticeably. Activity took place in different parts of the brain, as if sime people had well-developed conscience modules, and others did not.
A capitalist society tends to foster sociopathic behavior, and discourages empathy. It's easier not to care. People get confused over right and wrong, especially if they accept morally irrational demands of some religions into their moral reasoning. Others seize upon the 'out' of religion to square acts they understand to be immoral, but feel they have no other material choice or have some prejudice to justify. Looking at religion philosophically; what people are willing to believe in a deity is the moral reality they are willing to aspire to, so I would have to say some so-called athiests simply don't want to answer to morality as a matter of faith.
By morality, I would say that as social animals, we have a comfort zone of accepted behaviors that we use to contruct healthy, beneficial relationships with one another, that we understand, intuitively find, emotionally satisfying as well as, though not necessarily, of objective material benefit. Humanitarian ideals, as it were. Nothing's perfect, and so there are people on the fringes; psychopaths. (Both the cruelly black-hearted and the brainless bleeding heart I would call psychopathic, as they place their own gratification above all else). Sociopathic behavior is sometimes necessary as well.
A soldier, for example, needs to be sociopathic in order to function for a greater good on the battlefield, keeping to humanitarian values with his 'side' while readily destroying those defined as the enemy. A true psychopath would be useless as a soldier, as they would turn on their comrades should the need for self-gratification arise, even if they mimick well the behavior of a good soldier.
Less obviously, there are a lot of things that happen in society that would drive us mad if we dwelt upon the difficulty of resolving things out of our control, so we learn to overlook social malaise. As new positive moral possibilities become attainable, like ending slavery, racism, and sexism, people of conscience abandon a sociopathic mindset to foster and embraced the new social realty, whereas before they may have yeilded to social and material pressures to go along with it. Historically, there have been a few who have never accepted injustice, and could not be coerced or fooled into going along with it for any reason, just as there have been those to whom injustice made perfect sense and wholly embraced.
A natural psychopath does well to a degree, if they have the rote intelligence, but tend to be undone by their inability to truly understand moral behavior. The cannot fake it consistantly or adapt to new situations. Sociopaths do OK, till the habit of not thinking catches up to them, as it can be hard to turn off, keep turned off, and confined to one area of endeavor.
Fearmongering is the most common means of fostering sociopathy, whether by promoting a fear of the other, scarcity of resources, or letting people suffer unnecessarily for ingnorance or inexperience; like learning there is no Santa Clause, for example. So, most people will have sociopathic tendencies in some areas of their experience, but are still capable of independent moral reasoning in others.
Without Conscience
