Psychopaths generally feel most emotions. What they may not experience, at least the way non-psychopaths do, is the emotion of fear and as a result have trouble recognizing facial expressions of fear in others, are bad at predicting behaviors that will scare people and have reduced amygdala activity during moral judgments. See the work of Abigail Marsh for one.

I doubt a sociopath would provide advantages over and above high functioning autistics.

Edit: Also, the whole ASPD thing is just a DSM clusterfuck. It in no way carves reality and the joints and definitely includes more than just psychopaths. But it does look like there are a group of people who do bad things and also have an empathy deficit. As you might imagine, it's a really difficult thing to study.

Scott Aaronson had a post time ago about a common mistake: Empathy does not equal Sympathy.

These illnesses are definitely not well understood, but you may have characterized sociopathy reasonably when you described it as lack of sympathy without lack of empathy. How they can come apart is indeed not intuitively obvious, but lots of the ways the brain works are unintuitive. Sociopaths seem to be the mirror image of autistics, who seem to lack empathy but not sympathy (autistics have great difficulty understanding the feelings of others, but seem as motivated as anyone to avoid hurting others when they can figure out how).

Something to understand about Sociopathy/Psychopathy/ASPD is that your mental model has been effected by selection bias (also availability bias). The only ASPD people you hear about are those with problems. The ones you hear about do not just have ASPD. ASPD magnifies other problems, be they biological, social, or circumstantial.

ASPD + Conduct Disorder causes the type of psychopathic serial killers popular culture is familiar with. ASPD + a brilliant mind and educational opportunity means you'd make a great lawyer or CEO. A guy with ASPD who gets addicted to drugs is more likely to rob or steal to get a fix. A guy with ASPD who sells used cars is more likely to be a great salesman because he pushes for the sale even when it's against the interest of his customers. A gang member with ASPD is more willing to use violence or kill for the gang. etc.

People can go their entire lives without finding out that they've got ASPD, let alone others finding out. The problem with Psych statistics is that they can't get a cross section of the population; they can only infer from the subset of people who need psychological help. It's textbook selection bias.

To go into analogy mode, think of humans as web browsers. A normal, functioning human is Internet Explorer 9; it receives the information and acts on it the way you'd expect. An autistic human would be an out of spec browser from 1992; it tries it's best but it can't render everything right and doesn't quite know what's going on, even though it would like to. A human with ASPD is like Firefox with the Adblock addon; it knows exactly what the website wants it to do and exactly what's expected of it, but it refuses to render or be effected by advertisements. If you've got other addons (mental disorders) though, the interaction between the two will make the browser more likely to catastrophically fail.

http://worldsciencefestival.com/videos/moth_confessions_of_a_pro_social_psychopath

This might be worth a watch.

My understanding is, as with most characteristics, that psychopathy is not an either / or, but rather a "to what degree" . Give a psychopathy test to anyone and they will score somewhere between highly psychopathic and a low level psychopath ( even if at certain times ) . I think that the character traits involved, including a lack of empathy for the suffering of others, are the result of an emotional shut down or wall of defence brought about do to various levels of trauma and emotional pain experienced. At the root are psychological survival tactics, however misguided, as well as pain avoidance. Psychopaths learn that goal achievement for them is increased by taking feelings out of the equation. The harder the door is slammed on their feelings and the longer it remains so, the less likely it will be reopened. So psychopathy is not caused by a lack of empathy but rather, a lack of empathy, to varying degrees, is a resultant characteristic of emotional disconnect.

Any chance of getting even a minor explanation as to whether or not there is any validity in the information that I have presented?

has anyone considered getting a sociopath to work on FAI?

Since mild cases of ASPD are hard to distinguish from mild cases of Asperger's, and a lot of people with Asperger's are in programming, that doesn't seem like an off the wall idea.