I don't intend to offend anyone with this post, it's purely based on my own theorising and observations, having interacted with people who have autistic traits, and people with psychopathic traits. I've also studied a lot of history, and specifically looked into the people behind certain events, not just the events themselves. I also detest the idea that people with psychopathic traits are "monsters", as this is a harmful way of looking at people, who at the end of the day are just as human as anyone else.

When you look at each of these traits, you can see that they are the opposite of each other. An autistic person is limited in their ability to engage in many activities, due to sensory issues, overwhelming feelings etc. A psychopathic person has none of these issues, they are completely "free" to do as they please, no remorse, no emotions or conscience to stop them from doing as they wish.

Both conditions are characterised by antisocial behavior, impulsiveness, inability to control their behavior in a social setting(not always the case).

The concept of "masking" is the same in both cases. Some psychopaths don't mask at all, these are typically repeat violent offenders, who function completely at the whim of their impulses and have no regard for any consequences of their actions. Some autistic people also don't mask, they seem to be completely unaware of their own condition, and don't seem to notice that other people may find their manners uncomfortable.

And some people mask very well, to the point where it's impossible for someone to tell who the real person is behind the mask. Sometimes the mask slips, for a psychopath this might mean showing an emotion that is not commonly associated with the situation unfolding, or an autistic person might go into too much detail about their Warhammer collection.

Autistic people are at risk of being the victims of different types of crimes, for example sexual assaults, due to their inability of reading social cues. Whereas psychopaths are often perpetrators of these crimes, as they often are extremely skilled at detecting vulnerability in a person, and exploiting those weaknessess.

I also believe that psychopathy is a spectrum, similar to autism. You could categorise it on a scale of 0-100%, 100% being a completely emotionless, remorseless and predatory psychopath, and in the case of autism being a nonverbal, socially regressed person who needs constant care.

When you look at a lot of serial killers for example, their "empathy" is very selective. They can brutally murder a specific group of people, without seeing them as human beings, but somehow draw the line at killing elderly women for example. My theory is that these people don't actually feel empathy, they project their own feelings onto the world. In this case, a person like this might have lost their grandmother at a young age, and remembers how bad they felt about it. Hence, they see killing a grandmother as something that is bad. Whereas most people can feel empathy towards someone who for example lost their dog, even if they personally didn't have any pets themselves.

I think autistic people feel somewhat similarly, they often struggle expressing empathy towards something they don't personally understand.