[There is a great discussion about this post at the Slate Star Codex subreddit, with valid criticisms, which is worth checking out.]
Cross-posted to the Late Enlightenment.
Imagine that in some distant, cloudy mountain hideaway there is a city of evil Gandhis - or just unempathic monks - who spend all their waking hours meditating. As a result of the self-control they've created in this manner, their executive function is superhuman - after all, extensive meditation builds not just cognitive discipline but EEG-measurable physical changes in the brain. When finally you scale the last soaring frozen wall and scramble over the edge onto the floor of their lookout points, you have finally arrived in this storied, isolated monastery-city. You are greeted by intellects vast, cool, and unsympathetic, studying you from their great central plaza with piercing eyes. You find that you are the first visitor from your country. Suddenly a horrific pain erupts from the back of your neck, and you turn to see one of the monks withdrawing a red hot brand that he has just poked you with.
Obviously you demand to know why you deserved that. As they are merely dispassionately interested in collecting knowledge, this one calmly explains that they would like to see if your skin burns in the same way theirs does. You turn to see several more of them calmly approaching you with various glowing metal rods; behind them, in the fire at the center of the plaza, someone is handing out more metal rods. You tell them to stop, but they ignore you. Finally, you turn to the closest one approaching you, and punch him in the face. Your punch lays him flat out and his metal rod clangs to the ground.
"That's assault," one of the monks says. "We're going to have to lock you up now."
"Assault?" you shout. "What was I supposed to do? You made me assault you!"
The monk rolls his eyes. Only then do you notice various burns, knife and whip scars all over his face and arms. "You're like a child. It's not our problem if your self-control is so poor that you can't stand being burned a few times."
[Reddit user davidmanheim at the SSC subreddit suggested that this thought experiment would work better if instead of just burning our protagonist, the monks capture him and set up food for him that he is supposed to cross hot coals to obtain. When he goes around the coals and takes it anyway, he is locked up for theft. I agree that this would make the point better.]
To a person with a Cluster B personality disorder - including narcissistic PD or especially borderline - the world must seem to be filled with such evil cold-blooded monks. If I have BPD, then these people just can't see that when they withhold affection, that's so intolerable - it's just the same as a hot iron - that they're making me attack them to protect myself. (I have heard a severe narcissist in a psychiatric hospital, fighting while being restrained by staff after being refused special treatment, literally say "Look what you're making me do! You're making me do this!" The resemblance to what a five year-old might say is not coincidental.)
But this is more than just an interesting perspective - it's relevant to a critical assumptions that we make in liberal democracies. Namely, that people have agency, and this agency allows them to be responsible for themselves, and to some degree others. While (so far as I know) pain-tolerating monks do not exist, people with severe borderline and narcissistic personality disorder - with poor executive function and low distress tolerance - do exist. And we do lock them up.
It turns out that "agency" has buried within it many components, which do vary quite a bit across the population, and which profoundly affect people's ability to run their own lives and live with others. The one case where we're comfortable saying that humans don't have agency is children - but even that is somewhat arbitrary and agranular (many of us can think of a sixteen year old more capable of running her own life than a twenty-eight year old.) The monks would lock you or me up because we're at the extreme bad end of their distribution, just like we lock up people in jails or long-term care facilities, but we wait for someone to commit an act, of the sort that they are guaranteed to commit at some point, if they're at the extreme end of the distribution. As society becomes more complex, more and more people will commit such acts, and we'll have to get more honest and clear about exactly how we deal with them.