If that is a genuine answer, you’re a sick, disgusting human being.
I think it’s a reference to the book/play/movie The Bad Seed…
Looking into this, I found the wiki page of Maxwell Anderson, who adapted the novel for the stage. My first thought was, “Wow, he looks just like Phil Hartman.”
I do see a bit of a resemblance.
To be fair, I don’t think it’s such a horrible thing to do either if your child is doing what the kid in the Bad Seed did, either. But I mean, she did throw a puppy out of a window, dude. A puppy.
First of all, you don’t know jack. (Especially if you think all psychopaths light kitten tails on fire. As a diagnosed psychopath myself, I can tell you in all honesty, that if I saw someone light a kittens tail on fire, I’d kick that muthaf-----s sorry @$$ and take the poor kitten home with me. Get over your petty stereotypes, lady.) So don’t assume that your child has anything, let alone APD.
However, let’s assume for a moment that he does. I have but three points to make to you. (I’d be more thorough, but I’m probably wasting my time anyways. I just have a soft spot for disordered children with ignorant parents.)
1. Your child comes before his psychologists.
Once a child is diagnosed with ANYTHING, their credibility is shot. Because people refuse to understand. It’s easier to label the kid a delinquent retard and disregard his feelings and perspectives. Don’t. Also, don’t put too much faith in the “authorities” on psychology. Most psychologists know far less about psychology than the patients they tend to. Psych wards and asylums are frustrating, terrifying, and emotionally damaging places. Just because the resident doctors and nurses say their patients get the best care, does NOT mean it’s true. Be cautious. Of medication as well. Psychiatry is a field in it’s infancy. They use patients as guinea pigs. And the wrong medications can be very damaging, especially to a child. Even if he starts acting out less, it may not be the right med. He may just be mentally numbed and severely depressed. Remember, just because it gets better for you, doesn’t mean it’s better for him.
2. Antisocial Personality Disorder is incurable. Don’t try.
You can help your son be a better person. You cannot “fix” him. And it will only hurt both of you to attempt it. Rather, give him a good environment, try to understand his feelings and impulses, and use this knowledge (along with creativity and common sense) to create an environment in which he can develop into a more stable individual without feeling that you are trying to change who he is. Balance your reality with his. Learn to accept some of his uncommon views. So he can’t feel guilt? Get over it. He’ll probably be more successful in life for it, assuming he learns to reign in impulses and diminish any sadistic tendencies. Appreciate some of his stranger approaches. I’ve known seven true genius’s in my life. Five of them are psychopaths. If you nurture his intellect, he could have great potential. You just have to open your mind and find a compromise between his moral code and yours. (And yes, we do have moral codes. They’re just different from yours.)
3. Don’t be afraid to consider that his condition is your fault. It probably is.
Psychological disorders are 10% nature and %90 nurture. Whatever is wrong with your son, didn’t develop from the inside out. It’s the effect of his environment. It’s completely unfair and unrealistic, to assume that you’re entirely without blame in this situation. I don’t know what the kids life is like, but something isn’t right, if he’s setting kitten tails on fire. If you really care about him, consider all the options. And for f–ks sake, don’t ever let him hear you call him “monstrous”, as you so eloquently put it. Maybe these feelings of fear, disgust, and resentment you have towards him are what made him such a whack-job in the first place.
Oh and one more little tip, in dealing with him. Psychopaths don’t respond to sentiment and they don’t follow blindly. Appeal to his practical and self-serving nature, when you want something. It’ll make life a lot easier for both of you.
I don’t know whether the Grandfather from Hell would have been officially classificable as a psychopath or not, but - he was a cop’s son. He knew how the system worked as well as he knew how people work; he gamed both with equal skill.
Broke rules? Left and right. But the only time he landed in something resembling “jail” it was on purpose and it was beneficial for him (Civil War: the prisoners’ camp was “liberated” and him along with it, a few days later).
Impulsive? Yeah. That doesn’t mean he never planned ahead (see above) - but grabbing the supermarket cashier’s tits would fall into “done on an uncontrolled impulse”, I think.
Agressive? Yes; he mostly used his tongue, rather than his fists. The one time he hit Grandma, she grabbed his arm on the way back (and she was fully 14" shorter, but she stopped that arm short) and spit out “if you touch me again or hit one of the girls I am kicking you out.” Knowing that she had once kicked her own father out of the house and not allowed him back in until he fulfilled her conditions, he never again tried it.
Disregard for safety? No. He was very, very fond of his own hide. For example: he was a Casanova, but never went whoring, having acquired a healthy terror of VDs after his father (having heard he was thinking of going to rent some girls with his friends) took him on a tour of the local prison’s women’s wing. And for the safety of others? This same guy tried to pimp out his daughters first and his granddaughters later: he considered that his contacts were “high class” enough to be risk-free.
Irresponsible, no word, unsteady? He changed jobs every two years at most, always willingly, always looking for that greener grass. At a time and place where people moved from a town to another once in their lives at most, his family bounced back and forth between several towns.
Remorse? Only in the form of “this pisses my wife off; therefore and since when she’s pissed off I need to calm her down before we have sex again, I should either avoid this or avoid her finding out.” Other people’s fault? Oh yes, but then, Grandma bought that too: half an hour at most after any incident where he’d sexually assaulted someone in a store, on the street or at home, it would be that someone’s fault.
I don’t think that writing anybody off is a good choice, specially when that someone is really young. If I had a kid (or nephew) that I saw shared Gramps’ less-charming traits, I’d try to do what Duck says, what my great-grandfather did, and get the kid to see that it’s in his/her best interests to learn how to… how to put this… to learn the limit between “using people in a way they themselves find acceptable” and “abusing them”, and that it’s more profitable to stay in the first side. Might end up being a better President than most 
(No, Gramps’ mother was definitely NOT part of the positive influences - she was at least as obsexed as he was, and involved in the sexual abuse that he received as a tween - Gramps would probably have been much less horrid if that abuse hadn’t taken place. Oh, before somebody asks: great-Gramps wasn’t around when that happened, he was stationed in another town.)
So you’ve met my brother?