There are quite a few documented instances of sociopaths being exceptional in socially positive ways. There is professor Jim Fallon his ideas about psychopaths doing the "dirty work" and the "good work" that others can't or won't do as well. Joseph Newman believes that psychopaths are perhaps more inclined to be impulsively helpful than empaths. Also this post comparing heroes with sociopaths.
The reader continued about why sociopaths may be doing pro-social things, even when it doesn't involve the occasional "heroic" act:
In my experience, both personal and talking to others, sociopaths and psychopaths do seemingly random nice things for people more often than those seen as empathetic. If you walk the Path, you naturally want a leg up on those around you. You want to know what's going on, how to react, and you want people to defend you when someone tries to ruin your day. The best way to get that leverage is for people to like you and think you have their best interests at heart. Eventually, doing those small (but often meaningful) kindnesses becomes something the Path cares about, even if for no other reason than a flexible personality and unwillingness to change to suit others make it a routine.