Training oneself

From a reader:

I was wondering about you training yourself to enjoy and admire a different sex than you were originally attracted to. That seems like a very useful skill, and I wonder whether you can use it to train yourself to do different things, for example to enjoy watching bloody violence in movies more. I was always enamored by ways to test my self control and will, for example the ability to withstand pain, to control emotions etc. I don't self harm, at least not in the traditional sense. I do not cut myself or anything like that, and I do not get enjoyment out of things similar, or any release. But I do however do things such as ice baths to test my self control. But I do care about my self image greatly, and would not do anything that would defile my body.

Anyway, could one train themselves to become more sociopathic? Could you experience less emotions, especially less fear and stress? How do you think one would go around doing that? You mentioned you trained yourself using masturbation, it seems like any release of dopamine combined with an action or visualization would work, but it would have to be revived often. What would you recommend? Facing your fears? Deliberately putting yourself in stressful situations? Watch horror movies until you are never scared of them? Or even masturbate or eat sweet foods while watching violence? 

Or, how would one at will be able to invoke strong emotions, especially rage and happiness? 

Please help. 

P.S: I loved your book. You should if you haven't already read "The wisdom of psychopaths", it explores how psychopathy, lack of emotions especially stress and fear, can be very useful in some professions, such as surgeons and bomb defusers, or astronauts.

M.E.: I absolutely think you could be trained to be more sociopathic. Isn't that how we program child soldiers? Desensitize concentration camp guards? Empathy itself is very context specific. People cry over a child with cancer on the news here while millions are dying of AIDS in Africa. Not saying that it's bad or anything, of course you can't care about anything and everything. But it does suggest that it can be manipulated, either to care more or less about something. And brainwashing? I feel like that used to be more of a thing. Do we still believe that brainwashing happens?