Colloquially, these people are known as psychopaths and sociopaths. They differ in how they were created - psychopaths tend to be a product of a mixture of genes and upbringing, while sociopaths are mainly born from their environment, which often includes abuse.
Psychopaths and sociopaths are not all like the villains you see in films or read about in novels. In fact, very few psychopaths and sociopaths are serial killers like Jack the Ripper or cannibals like Hannibal Lecter. Many of them are your colleagues, parents, friends, or even partners.
But you may not be wise to them, because psychopaths and sociopaths are very good at hiding in plain sight, so you may not notice them unless you know exactly what to look out for.
Psychopaths are calm and collected under pressure, and have something called a "resilience to chaos." This means they thrive in situations that others would find highly stressful.
Sociopaths, however, are more vulnerable to anxiety, so they do not do as well in those environments. They're more prone to angry outbursts and abusive language, while a psychopath can manipulate without seeming like a threat.
When stressed, a sociopath may fly off the handle, but a psychopath will remain calm. This is one of the main differences between the two, according to psychologist Elizabeth Lombardo.
"When a psychopath interacts with you, if they get upset, they can keep their cool, but a sociopath will lose it," Lombardo told Health. "They're really hot-headed. If things don't go the way they want them to, they'll get angry and could be aggressive. They can't keep it together and have emotional outbursts."
Sociopaths lack empathy like psychopaths, but they do tend to feel anger and stress like everyone else.
"Psychopaths are more likely to be thrill-seekers, and more likely to push the envelope on life," Adrian Raine, a professor of criminology at the University of Pennsylvania and expert on psychopathy, told INSIDER. "It's because they lack fear and they lack conscience, and they have this blunting of emotions."
Essentially, this means if a psychopath is controlling you, you probably won't notice. They'll be able to explain away any strange behaviour, and never get upset if you confront them. A sociopath will have more of a temper, so you may be less likely to trust them from the start.
This is why psychopaths can make great con artists. They can mimic other's behaviour and be charismatic and charming. A sociopath's plan, on the other hand, will be much more obvious - especially when they become enraged.
There are ways to handle people with antisocial personality disorder, whether they are a sociopath or a psychopath. If you think you are a target, make sure to maintain your boundaries, and don't ever try to hold them accountable for their actions.
Psychologist Perpetua Neo told INSIDER trying to get them to change or apologise for how they treat you is what keeps you in their toxic, abusive cycle. Research has shown that psychopaths and sociopaths are wired differently, so the best thing to do for your own mental health is accept you can't change them and distance yourself.
"The thing about [psychopaths] is they seem to have been programmed in the same manual," Neo said. "When we notice a commonality, because they all seem to follow this manual, we finally have the words to explain it, and we can walk away."
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