Getting technical there… You mention one study but plenty of other studies mention “sociopaths” and “psychopaths” and their different manifestations within APD, which fit my descriptions. So both terms are perfectly viable when making a distinction.
Sociopaths
do form attachments although not easily, which totally fits Bella, as you can read in the spoiler below.
At the end of the day Bella still exhibits a ton of antisocial behavior akin to “sociopathy”. Her mom who is a psychiatrist reins her in a lot and has likely done some work with her through the years.
Also that guy from the movie looks like a psychopath.
Well, yeah. Same principle though.
I did some research to find alternative classification that are closer to what you were talking about. There's the pscyhopathy checklist that is sometimes used in criminal psychiatry. I think it can be reliable.
It ignores sociopathy. Like I said, sociopathy is just a popularized term used in different contexts. Instead, it makes a distinction between a person with antisocial personality disorder and a psychopath. A person with APD has a much higher risk of suicide than a psychopath who essentially should not have feelings of remorse and guilt. Simply put, a person with APD could be Bella and a psychopath is a typical recidivist criminal or a serial killer who also does not suffer from other disorders that can provoke a suicide attempt.
When the final version comes out and I play Bella path, I will check your theory by comparing her to the description of APD in the DSM. Or you can do it, there's not much to read.
As for Vanessa's case. I think we both made the wrong conclusions about her. Yes, she shares some traits that are very relevant in a person with antisocial personality disorder (sociopath/psychopath, whatever). But none of them are her predominant personality trait. Her core is narcissism. So instead of antisocial disorder, she may have narcissistic personality disorder. From what I've read, the problem is that they are on the same spectrum and are so similar that in practice it's sometimes difficult to determine which of these two disorders a person has.
People with antisocial and narcissistic personality disorders are tough-minded, exploitative, manipulative, egocentric, and deceptive. Vanessa has all these traits. However, narcissistic personality disorder does not always include impulsivity and aggressive. Vanessa is actually pretty bad at hiding her negative emotions, but she can control herself. When Nika makes verbal attacks towards her, she shows this angry face
and then tries to cover her dissatisfied reaction behind a fake smile. She would be much more hot-tempered if she had APD. She also doesn't have any history of bad behavior in childhood or criminal behavior in adulthood, at least we don't know anything about it. Otherwise her childhood would be more like the one Leia and William had. Vanessa with APD is basically Leia minus her affection for her brother. Finally, people with APD do not crave admiration and envy and do not reflect it on others as passionately as Vanessa does.
She is obsessed with self-praise and self-love to the point where she more-likely sees it as the purpose of her life. It's the difference between being a narcissist and having a narcissistic disorder. We all know she's a narcissist, but it's one thing to have a tendency toward it, and another to have it as a major trait that interferes your daily life.
From DSM
Now her behavior becomes clearer and more consistent. "That dumbo can't talk about anything but fashion and how she used to buy this and that-" said Bella after meeting her. I thought she suspected Bella and outplayed her, but maybe she didn't, she was true self the whole time. But that doesn't mean she's less intelligent and manipulative she seemed to be before. It's just that her abilities are actually limited by her disorder.
She's probably not too emotional, as people with NPD are described here. But everyone is different, even those who have common mental illnesses, they can still be predisposed to one or another behavior. Besides, we haven't seen her under real pressure. If Nika starts acting too aggressively towards her or ignoring her new attempts to get his attention, she may experience an emotional breakdown. And if that happens, then she will take off her fake mask of coldness, and we can definitely say that she indeed suffers from NPD.
My only problem with her having NPD was that she also praises the looks of people around her. I thought it contradicted narcissistic disorder. But I was wrong and they actually do it: "They may feel that they can only be understood by, and should only associate with, other people who are special or of high status and may attribute “unique,” “perfect,” or “gifted” qualities to those with whom they associate. Their own self-esteem is enhanced (i.e., “mirrored”) by the idealized value that they assign to those with whom they associate."
Damn. I may be reading too much into it as usual, but I think what we have under the spoiler is the most accurate and detailed description of Vanessa possible. I didn't compare her to the description of antisocial personality disorder though. Think I'll do it later. But I'm almost certainly sure that she indeed has one of those two personality disorders. Most likely narcissistic. Her behavior is too odd, but consistent, and falls perfectly under each point of the description above.