Something to consider as we delve in to part four is what we really mean when we talk about communication. There are certainly many ways to answers this question and entire fields dedicated to the science of communication in both people and non-human animals. One of the questions that puzzle scientists working on animal communication is the one of intent. The question of whether or not non-human animals communicate with the intention of transferring information to others is a complex and highly debated one that I won't be diving too deeply in to within the confines of in this resource. Regardless, an important thing to note that we can be fairly certain of is that at least some information transfer between both people and animals is unintentional, at least as far as the sender of that information is concerned. (See for example Bar-on and Moore, 2017, for a discussion on this topic.)
As the highly social creatures we are, both people and parrots are very skilled at picking up on what others are doing. As long as they are alive, everyone is always doing something, so there is always going to be something for someone else to observe. At least some of the behaviors and body language we have- and will be discussing in this resource are not necessarily intended to communicate anything to us. This does not mean that it can't provide us with a lot of useful information. A parrot having relaxed feathers, an even weight distributiton and an almond-shaped eye is information telling us that this parrot is exhibiting low arousal, but this is not the same thing as the parrot intentionally communicating this to us. I the same way, a (human) friend shivering when it's cold outside isn't necessarily intening to communicate anything to me; they are just having physiological responses to the current environment. Regardless of intent, this is still information that tells me my friend would probably feel more comfortable if I lended them my jacket.
It's also worth noting that many animals also receive and process some information without being consciously aware of it. One interesting example is, in fact, our own species. If there's one thing the current situation in the world (2020, need I say more) has shown us it is that people really like touching their own faces. A lot. Why is that? It could just be a bad habit, but when such a seemingly huge part of the human population does something, one might hypothesize that there's something more to it. One (perhaps out of many) possible explanations is apparently that we really like to sniff our own hands; something known as self-sampling. And we tend to do it more in certain contexts, like right after we have shaken hands with someone else. Some researchers suggest this behavior might function to facilitate active but subliminal chemosignalling (transferring information using chemichals, like scents or pheromones) between people. This is just one example out of many to illustrate that we pick up and are influenced by many more cues and signals that we are not consciously aware of than many of us think. Far from all information processing is deliberate.
4.1 DO YOU REALLY MEAN THAT?
Dorit Bar-On & Richard Moore (2017)
Pragmatic Interpretation and Signaler-Receiver Asymmetries in Animal Communication
Frumin et al. (2015)
eLife; 4:e 05154
In Kristin Andrews Jacob Beck (ed.), (2017) The Routledge Handbook of Philosophy of Animal Minds. Routledge. pp. 291-300