Why are cats mean?

It depends on their childhood, and how they are looked after. Like humans, if they don't get much contact or they are abused, or saddened in their life, this will mirror how they act in the future. If a cat is not in contact with humans when it is young, or taken away from its litter-mates too early (six to ten weeks), then it is most likely to be more aggressive as it never learned how to behave around people and in normal situations.

Some adult cats become "mean" if they are mishandled. Cats do not respond well to punishment, whether it be violent actions, sprayed water or harsh voice. It is most likely the cat will respond to this negatively as it will learn to fear the owner (or any other human) not treating it well. This could mean lashing out, hiding, and hiding certain behaviours it knows it will get punished for.

For cat owners, it is ideal to learn your cat's behaviours. What may be "mean" to us is usually just the cat trying to communicate its needs with us. A cat misbehaving is usually not the case, it is just doing something perfectly natural.