I am not aware of a book written 'specific' to psychology of birds. There are several that touch on it as part of a more generalized offering of owning/caring for companion parrots. If they exist, it is highly likely that they would be targeted to a specific group of birds. This based on the psychological patterns of companion parrots would be very different from say; Eagles or Hawks. It addition, with in companion parrots you have flock groupings and social (family) groupings, which patterns would also differ. With the limited research and PHD funding in the Avian World, funding for such a study would be hard to find.
There are several books that look closely into the "Art" of Reading the "Body Language" of Companion Parrots, which more commonly target social (family) groupings of parrots. See the first Posting in the Amazon section of this Forum. The cross-section of books in all areas of Companion Parrots range from very good to very, very poor. The same is true regarding body language.
By understanding their body language, it allows us humans a glimpse of the psychology at work below the surface, and with that, a better understand of our parrots. I am guessing that this is what you are really more interested in, correct?
Sally Blanchard has several books that may interest you: Companion Parrot Handbook, Amazons, The Beak Book.