@Dan_Gero, fair enough. I was actually pleased when finding that article since I was trying to remember the species classification details, as it's handy whenever you look something up, or want to know what is related to what.
@Draq, that indeed is the point though. Dogs are pack animals and yes require you to take care of them more (though in the case of guide dogs of course, this isn't entirely one sided), however most dogs will see humans as part of their pack, will want to be around people, and will be a definite presence, giving affection and wanting human contact, thus are more likely to become a real companion.
Cats can! Be affectionate, can get attached to people, but equally there are a lot of cats who are solitary loners, and see humans mainly as a utility, or actively dislike people, and there is no guarantee that when you get a cat, even a fluffy little kitten, that it'll be the sort that will bond with people and care for human attention.
this isn't of course to say all! cats, I've met some lovely cats who definitely like people, but where as with dogs your almost always guaranteed that if you get a pet dog, and put in enough time making friends, the dog will like you in return, the same is not true for a cat.
Btw, last year my lady and I went with a couple of my mum's friends to the cat Cafe. This is exactly what it sounds like, a cafe where they take care of cats, and have a lot of cats wandering around the place that you can just chat to.
I met the most lovely Maine coon cat called Heethcliff, who was almost like a feline version of Reever, my dog.
Basically, he was a huge ginger rug of a cat who simply wanted to lie there and be stroked, and if you started stroking him, he clearly expected you to do it all day .
Ironically, Reever, who is now quite an old dog, has exactly the same personality, indeed she's lying on the carpet beside my sofa while I'm writing this.
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)