Introducing a new cat to an existing one

Question
Dear Norm:  
I have a similar question as a recent one on 2-11-10.  I have a neutered 10 year old female Domestic Shorthair/Ragdoll mix cat who has been an only pet in the whole ten years.  She is affectionate with me and greets my friends when they come over, but isn't overly affectionate with them.  Since I work about 9-10 hours a day, I would like to get a companion for her and to add to my feline family as well.  I volunteer at the local Humane Society and met a wonderful 1 year old neutered Domestic Shorthair who is very loving, affectionate and laid back in personality. I came home after our meeting and let her smell his scent on me then gave her lots of attention.   A few days later, I brought him home for a few days for a visitation to see how it would go.  I have followed the suggestions of introduction given on several websites and am hoping for the best.  So far only some hissing on her part and a little bit of "attitude" has been expressed to me, but I can see she isn't real happy about the interloper.  I have "cat-sat" for friends, keeping the animal separate from her and she tolerated it, but didn't really like it.  It has only been a few days.  Am I pushing her beyond her limits of what she will tolerate or do I need to give it more time?  An adoption decision needs to be made in a couple days.  I would like to for my cats to love each other as much as I love them, but that can't be forced, I guess.  Please advise.
Thanks,
Julie in Kansas

Answer
Julie,

Given the age of your female, you really have not given it nearly enough time. You may be talking about weeks or even months for things to settle down.  You need to just let them figure it out and stay out of their proceedings.  If they hiss and spit, ignore it.  Also, do not ascribe human emotions or motives (except jealousy) to things cats do. They do not think like we do!

If they begin playing chase, even of it ends up in a "fight", that will be a good sign.  Any mutual grooming, sharing of food dishes and litter pans are all hopeful signs.

Please let me know how it goes.

Best regards... Norm.