I am reading all that I can about parrot behavior - book after book, cover to cover, as fast as my little (older and older) eyes will take me. Here's another one where the books disagree: height dominance.
The older books (as I have said, written before about 2002 or 2003) all talk about height dominance - if your parrot is higher than you, he will feel dominant and agressive. They recommned that you take an agressive parrot and place him on a low perch or on the floor. This will, suposedly, make him more docile and obedient.
But, wild animal trainers disagree - they say that in the wild, the height makes them feel more secure, not more dominant! The perceived behavior is the same - the parrot becomes more willing to be picked up and less likely to bite. Melinda Johnson in Clicker Training for Birds agrees.
The difference in why the bahavior comes about - dominance vs. security - is profound. And so is how you view it and, more importantly, what do you do about it. Do you view it as a struggle for dominance - or do you view it as an opportunity to make your parrot feel more secure? Do you try to intimidate your parrot into submission - or do you adjust his level of security?
This is important - very important - if parrots are not trying to establish dominance, the trainer makes a big, harmful mistake if he tries to assert dominance over the parrot. Again, what works for the pack animal is probably counterproductive for the flock animal - the parrot.