Why is my cat so mean and unfriendly? Is there any hope for him to change?

Ok here’s the situation. I love my cat Barry more than anything in the world. To me, and my boyfriend, he is the snuggliest, most loving, cuddly, caring cat I’ve ever met. And then comes everybody else on the planet. He hates them all!

Backstory: We have owned Barry for a year and a half. He’s about 9 years old now. When we got him, he had tons of records from his two previous owners. Originally he lived in Canada but when he was 4 (ish) he was given to someone else, who also kept him for 4 years. His papers said that he was more comfortable with women than he was with men. That is very true….not that he’s nice to my girl friends, but he’s much nicer and less feisty to them than he is to any guys. He has no teeth (when he was dropped off at the humane society, his teeth were “rotting” so they pulled them all. How the hell does that happen? I wanna go kick his previous owners ass. Kinda makes me think he was treated extremely poorly, and thats why hes now deranged) or claws which I think is part of the problem. Maybe I’m giving him too much credit, but I think he knows and feels like he has no chance against anybody, and therefore is just mean and stand off ish to everyone as soon as he meets them. :(

This is what he usually does when someone tries to pet him or hold him, OR SOMETIMES, even when you sit down near him! (This is excluding my boyfriend and I of course). He’ll make loud, unfriendly groaning noises, hiss, “claw”, scream….then he usually runs away. There’s no winning.

Do you think he’s just extremely protective of us? He was friendly at the shelter when we went in to see him for the first time. Now, even when friends come over that he’s known (and several that have spent weeks taking care of him every day while we were away) he is still just as mean. But, we’ve been told by friends, and by our roommate, that when we leave for, say, a week, and it’s just Barry and him, he’s perfectly fine!!! It’s almost as if he’s mean just because we’re around.

Here’s another monkey wrench: A couple months ago my boyfriend and I got a traveling job and had to leave Barnacle with a friend in NYC for about 6 weeks. Apparently he was friendly to them and very loving, but not just that, every friend they had over he loved too! He’d cuddle them and show a ton of affection, rarely hissing and clawing.

PLEASE HELP. I know he’s 9 and was obviously EXTREMELY poorly socialized when he was younger, but we constantly have friends over, or our roommate does, and it’s not working out with him being so mean for no reason all the time. It makes me really sad too, because I know his cuddly side, and he’s such a great cat, TO US. :( What can I do?!?! I’m trying to reward him with treats whenever he’s nice to someone other than us, but it’s so rare I can’t!