Even identical body language or behaviors, performed by the same individual parrot, might have different functions in different contexts. For example: my grey parrots will, like most, sit and talk, whistle and make sounds when relaxing during the day; they try out new sounds and practice old ones. In this context, they will often repeat their own names several times, often with slightly different inflections here and there.
They have also learned that when I give the cue "what's your name?" -> if they say their name -> they will get a treat. Additionally, they sometimes use their names as contact calls to get my attention when I'm in another room, where the function is to get me to call back or come to them. When I leave the room -> echo says "echo" -> I call back to him.
In other words: these behaviors are structurally similar, but functionally different, as we discussed in module 2.6 about the different ways we can categorize behavior.

Categories can be very helpful, but they can also trip us up badly if we're not careful about how we use them.  
It's very easy to confuse structural similarities with functional similarities. This is why if you ask a behavior consultant "how to get a parrot to stop screaming" their answer (if they're any good) will be: it depends. I have had cases where birds scream in order to gain attention from- or proximity to people, which is common. However, I have also had cases where parrots scream because it results in someone they would rather keep a distance to leaving. Same behavior, different contexts, entirely opposite consequences - and very different solutions are required in order to change the behavior.

In parrots, we can see many behaviors that might look similar but that are functionally very different. For example, look at the macaw in the video below:


The macaw is moving from side to side, lifting it's feet and swinging or bobbing it's head. Hey, that sounds just like dancing! I might notice these structural similarities to a concept I'm already familiar with and think that since the macaw is doing these things, the macaw must also be dancing. From there it's easy to think that dancing is something we do for fun, therefore this macaw must be having fun.  In this case I am (wrongly) assuming a similar function from a similar appearance. We will sometimes see parrots perform repetative movements like these in stressful situations that they can't escape, or when they want to get closer to something without being able to, as discussed in part 1. In order to determine what is actually happening in this video, we would need a lot more information. It's also important to note that similar structure does not mean identical structure. For example, when we look at a parrot that is moving rhytmically to music, we will often observe a much more relaxed body language. We do see repetative movements, but the body is loose often loose and bouncy, feathers are in a relaxed position and we tend to see a more almond shaped eye. When we observe repetitive movements in what would appear to be a stressful situation, like in the video above, we tend to see a stiff body, flattened feathers and very round eyes. (Think back to section 2.5 on granularity.)