I have seen roosters fake tid-bitting. They pretend to have food and call over the hens. If the roosters are actually aware that they are that there is no food to be had, then they are engaging in deception, which takes some brains. I know crows have been observed by scientists pretending to hide food while other crows are watching and then go and hide it somewhere else in secret, which is clearly deception. Considering that crows are considered one of the smartest birds around, I doubt that chickens are quite as bright, but I bet that chickens are easier to train.