There's no surefire way of self-diagnosing yourself as a sociopath, as sociopaths also tend to lie in tests like these.
But if you recognized yourself or others in these questions, you might want to seek professional help.
Thomas points out that many sociopaths do not want to end up in prison, or as psychotic outcasts. They can use their skills to be successful in business, in ways that less single-minded people cannot.
(They're just not your friends, is all.)
Along with this, I just learned from WebMD that what I thought was a sprained ankle is actually a cancerous brain tumor in my lungs.