A study done on people found that lonely brains crave company the same way that a hungry brain craves food which tells us that parrots that are left alone for hours and hours every day could not possibly be content in their life. There are no studies about this but one of my 'off-the-wall' theories (theories for which I have NO scientific backup but observation and a gut feeling) is that parrots, because they evolved to be 24/7/365 surrounded by their family have a lower threshold when it comes to dopamine production - meaning, their brains need more and constant dopamine so as not to be depressed.
https://www.sciencenews.org/article/lon ... _Headlines