I am sorry but it seems that cats are being held in some 'special' catagory of ability to learn and personally I think they are way too smart for that
Oh, they're smart alright - VERY smart. But very different than dogs, in that they have NO desire to please people or to please anyone but themselves.
Yes, they can learn all kinds of things, you just have to use other methods than you would with a dog. They aren't being held in a 'special" category, they are just a different species and must be handled differently.
I can tell my dog "Leave it" because I said so. She wants to please. A cat needs different motivation to change it's behavior, which is why I made the suggestions I did. Doing anything punitive to a cat who is already showing aggression could very well increase the aggression or have other unpleasant side effects, like avoidance of the litterbox, especially in a 10 year old cat who could be easily stressed.
Aversives can work, but must be done in a way so the cat does not connect you with it. For example: Cat gets on the counter and finds stuff to eat. Behavior is reinforced and no squirting with water will keep it off the counter when you are not home since staying off counters that have rewards makes NO sense to a cat.
BUT if you put sticky tape and no food the on the counter and cat jumps up, the result for the cat is "This counter makes my feet sticky and there is no food and I wont' bother coming here again."
Cat doesn't think, "Oh my owners are being mean to me and making my feet sticky". That's the difference.
Another example:Cat is scratching couch. Screaming and spraying with water will work WHILE YOU ARE THERE. Gently guiding cat to catnip laden scratchpost and giving pets and treats for using it will work even when you aren't there, since using the scratchpost has now become more satisfying for the cat than scratching the sofa. Cat wants to please itself and doesn't give a damn about pleasing you.
Punishment doesn't work with birds either unless you are planning to abuse it to the point where it obeys out of fear. It must positive all the way.
Hope this makes sense!!