I'm a sucker for cat science even if I've found a lot of it to be a load of old codswallop, seemingly researched by people who've never had any contact with a cat themselves. Some things that are obvious to cat owners appear to be missed by scientists.
Knowing that, I nevertheless ploughed on after reading the article I link to. Some boffins have developed what they call the Cat-Tri+ measure of a cat's level of psychopathy. It takes the form of 46 questions about your cat and is based on a similar thing that already exists for humans. Obviously the questions are changed to be more relevant to cats because people, even psychopathic people, don't routinely chase mice around the house and bite their heads off.
I answered all 46 questions. My cat is now the only pet in this household, but In the past she has lived with other cats and a dog so I was able to answer related questions based on my historic experiences of the cat.
You get blocks of answers related to specific traits and then an over all score, which for my cat was 1.458. Annoyingly, I couldn't find any instructions about how to interpret this score, even in the paper itself, but it's fairly obvious by the test that a higher score is more likely to indicate psychopathy. As the highest possible score is 5, I conclude my cat is not a psychopath. I think it would be far too much effort to be a psychopath for her.
I do however have a problem with this test. Psychopathy in humans is a deviation from what might be considered normal human behaviour. It may or may not be caused by a malfunctioning amygdala, but it's the relative change from what society calls normal that is measured.
This test is too anthropomorphised. Even though they've changed the questions to be relevant to cats rather than humans, I don't believe they've given ample consideration to what's normal for a cat. A lot of cats bite the heads off mice and birds and present their human slaves with the body. They do so gleefully, often implying "Look at this fantastic thing I've left on your kitchen floor for you — aren't I kind to you?" The point is that a cat biting the head off a mouse is not as much of a deviation from normal cat behaviour as the deviation from normal human behaviour we'd assign to a person biting the head off, say, a sheep.
So I'm taking this science with a pinch of salt.
If I ever did have a cat that was psychopathic, it would most likely have been a tortoiseshell I had called Bronte. She ruled the roost even in a household that had two male cats and a dog. They messed with her at their peril. As did we. We took to using an old pair of oven mitts if we had to load her into the cat-box, such was the risk of injury.
I remember taking Bronte and another cat of mine, Schrody, to the vets at the same time. He put both boxes on the table and took Schrody out of her box to deal with her first. As he was leaning down to deal with her, Bronte squeezed her paw through the grill of her box and swiped the vet on the head, eliciting a nasty gash. A preemptive strike if you like. I apologised on Bronte's behalf but fortunately the vet said it was his fault for leaving Bronte on the table while he was dealing with Schrody.
I'll never forget leaving that appointment and seeing a vet stood at the back of the room dabbing his head with a cloth to stem the blood flow.