Having worked on a farm, I can confirm that chickens are unsympathetic and occasionally cannibalistic, especially when large numbers live together. (We had one case where eggs were getting eaten, and discovered the culprit one day with yolk on its beak.)
If you converted them all to humans, they would be a bunch of jerks of breathtaking stupidity. The Biff Tannens of Back to the Future. I love that Sarah French is looking at how to mitigate the bullying.