A user of quora.com asked the question whether cats can tell if someone is bad, good or neutral? The person cited the example of a person who came around to their home to adopt a kitten. The person thought that the man might be a bit dodgy and therefore told him that they would have to check out his references. The man went away. He thinks that his cat "gave me a very disgusted look and took the kitten [the kitten that was going to be adopted] and laid with her all night. Luckily the man and his kids never returned."
He thinks that his cat recognised the potential adopter as a bad person. Is he right? I think we have to take a commonsense, more scientific approach.
I don't think cats can read the minds of unknown people with whom they have had no previous experiences if the person is doing nothing. I don't think cats have a telepathic ability to pick up bad vibes from a person. So, I don't think, without more, a cat can tell if a person is good, bad or in between the two.
They can tell if a person is bad through their actions obviously. If a person abuses a cat that cat will then be fearful of that person if it happens more than once. My thought is that if a person inadvertently harms a cat but then is loving towards the cat afterwards, the cat will forget. But consistent abuse of any sort will clearly make the cat fearful of that person.
And there's no doubt that in good relationships between a cat owner and their cat, the cat warms to the person and a very close bond is created. So, cats recognise good people through their actions.
The big question, I admit, is that whether cats can sense if a person is bad. I don't think they can. A favourite author of mine and a renowned biologist, Dr. Desmond Morris, says that cats tend to go towards people who dislike cats if in a group of people there are those who dislike cats and those who like them.
He argues that cats do this because people who dislike cats don't look at them and when people look at cats, they can stare at them and staring can be off-putting to a domestic cat. That's his theory. I am not altogether onside with that theory.
But he is more or less saying that a person who dislikes cats and therefore is liable to be unpleasant around a cat can draw a cat in. This indicates to me that the cat is not picking up the fact that a person might be a cat hater and therefore to be avoided. Cats operate on simple physical, visual, olfactory and auditory signals to decide whether to go towards or move away from people and other animals.