EDIT: Let me just point out that this isn't a directed response to you Liz or so specifically to what you said but to the general discussion. Just using a few of your shortened points as a summary for the general discussion.
liz wrote:All animals feel fear so why can't they feel contentment. Why would they get attached to us if not for love. They feel all of the emotions. If you don't believe it I feel sorry for you.
The problem with all of these stories is that individual people are just making them up. They are primarily superstition and anthropomorphism based and not fact. It is more likely that people just remember these coincidental stories because they were going through a rough time than that the animal displayed emotion. Remember, I am not saying that it is impossible that animals feel emotions but rather that it has not been proven and being certain that they do can be harmful.
You can't even know that they feel fear as an emotion. It can just as well be an entirely instinctive or learned response. Likewise contentness may be nothing more than an excitation response to getting something that the animal requires.
liz wrote:Why would they get attached to us if not for love.
Could just be boredom. After being stuck in a cage (that we put them in), they may just show excitation to receiving freedom or attention.
The problem with all of these beliefs, anthropomorphisms, projections, hopes, superstitions, and any other kind of unverifiable postulations is that if you're wrong (and more than likely you are) you may be taking the wrong course of actions. If you purely assume that your pet has emotions but in fact does not, the things you do to/for it may be pleasing to you but may be potentially useless or harmful to the animal.
The best approach is a behavioral one. When you give the animal choice and observe its behavior (whether learned or natural), you are getting a more objective glimpse at how it functions. Reinforcement and punishment are observable phenomena with consistent results. Whether it appeals to the animal's emotions or to an entirely automatic learning response, makes no difference. Positive reinforcement increases behavior and punishment reduces it. If you observe positive reinforcement, then you know that what you are doing can be done more without harm to the animal.
For example if giving head scratches makes the bird feel the emotion of being happy, that's great. However, just making it up in your head that since you gave the bird a head scratch must mean you made it happy is a terrible mistake. You could just as well be making the bird unhappy or upset by doing so. Just because it makes you happy to scratch the bird doesn't mean it makes the bird happy. This appeal to emotions approach is anywhere from useless to a set back. On the flipside, if you use a behavior based approach, it won't make a difference whether or not the bird has emotions. If you develop a hand signal for "I am offering a head scratch" (what I do is wiggle my fingers like I'm about to do it) and the bird walks over to you of it's own free will and bends its head down to accept it, then it is a fact that doing so will be a good thing. Whether it will appeal to a happy emotion or will just satisfy the instinct to receive this won't make a difference. You are still doing something that will elicit similar freewilled behavior in the future.
People who assume their pets are emotional and like to project themselves too much on their pets tend to be much more forceful and presumptuous. They don't really think about what the animal really wants because they assume they know because of a system they made up. "Look at his eyes, he wants a head scratch" is not proof that this is what the bird wants. It's just a human reading their own emotions into the animal and then possibly forcing those unsolicited actions upon it.
Finally, even if parrots were to have emotions, there is nothing to say that they are the same as ours. Since you don't know what real emotions a parrot can have, you just assume they are the same as your own. So even if parrots have emotions but supposing they are different (and quite likely they are since they are birds and are 300 million years of evolutionary history removed from mammals), projecting your assumption that their emotions are like yours again undermines what they would actually be feeling. Birds can see at higher frequencies and see ultra violet. Their perception of the world is already quite different than ours. It wasn't long ago that even this wasn't known. You can't just assume that they have emotions and that if they do that they are the same as yours. There is no proof beyond people's own stories that are only reflections of their own emotions anyway.
PS Just because I am not convinced that parrots have emotions doesn't mean that I don't treat them like they do. Sometimes I talk about them like they do and I talk to them like they do. However, I do not let this dictate my approach or dominate my understanding of them. I take care to appeal to both schools of thought as opposed to limiting myself to one and potentially being wrong. Since we don't know for sure, the behavioral model and a reduced presumption that they have emotions is the safer way and more likely to bring success.