My response:
If your friend has been outting himself to you as a sociopath then he has really done all of your work for you. Now you just continue the joke with him to see what else he says -- e.g. when he mentions something about sociopathy or if he exhibits some of the traits, you could make a small little observation or joke like "that's just the sociopathy talking."
I wouldn't tell him anything about what you know. He will be able to discern it eventually, but it is best for you and your own self interest to watch him for a little while knowing what you know but without him knowing what you know. You need to do your own method of datamining on him because as much as you read, there is still so much to learn, particularly about things specific to him.
After you are sure that you are committed to being supportive to him despite who he is, then you can start to be more explicit about things, still joking but painting them in a positive manner. For instance, maybe when he does something positive or particularly cunning or powerful you can say something like "go go super sociopath," or something similar to make it sound like his sociopathy is some sort of super power and not anything to be ashamed of.
But be careful before you make any commitments to him, because it sounds like you are the type to keep your commitments and you may think you know him and can stomach him right now, but I've had friends try before and fail and it is much worse than if they had not tried at all (see the recent post on rejection).
If your friend has been outting himself to you as a sociopath then he has really done all of your work for you. Now you just continue the joke with him to see what else he says -- e.g. when he mentions something about sociopathy or if he exhibits some of the traits, you could make a small little observation or joke like "that's just the sociopathy talking."
I wouldn't tell him anything about what you know. He will be able to discern it eventually, but it is best for you and your own self interest to watch him for a little while knowing what you know but without him knowing what you know. You need to do your own method of datamining on him because as much as you read, there is still so much to learn, particularly about things specific to him.
After you are sure that you are committed to being supportive to him despite who he is, then you can start to be more explicit about things, still joking but painting them in a positive manner. For instance, maybe when he does something positive or particularly cunning or powerful you can say something like "go go super sociopath," or something similar to make it sound like his sociopathy is some sort of super power and not anything to be ashamed of.
But be careful before you make any commitments to him, because it sounds like you are the type to keep your commitments and you may think you know him and can stomach him right now, but I've had friends try before and fail and it is much worse than if they had not tried at all (see the recent post on rejection).