Everyone has an opinion on how smart their own chickens are. It is a bit like children, all yours are smarter than next door’s, but some of yours may be smarter than the others. Chickens are unbelievably instinctive, they just know a hugely impressive lot.

Chickens can learn tricks too, but they need a very quick positive reinforcement or reward.
Unlike a dog, who is reflective and can work out what part of their recent behavior you liked, chickens seem to live in the moment and trainers have found that sounding a clicker and then rewarding with food immediately is only way to let them know that you liked what they just did.
The clicker spans a simultaneous association of act, sound and food reward. As a trainer your own reaction time to provide food is too slow to train a chicken with out a clicker.
(See YouTube training chickens with clickers.)

YouTube ‘training chickens Dr Sophia Yin’

That is not to say chickens have no memory, they have good memories in some areas.
They can pick out members of their human family easily and also, in a flock of twenty, each chicken knows exactly where they and the others stand in the pecking order.

While I like chickens to be responsive to me and to be easily organized as pets, most tricks are a bridge too far, in fact I get bored training them before the chickens do. And I don’t even play the xylophone myself.

Chickens have a recognizable vocab of around thirty calls.
One obvious call is the cackle which says ‘I have just laid and egg’. As a child some of my neighbours called eggs ‘cackleberries’.
Or you can think of the dominant rooster, each morning checking in the survival of the surrounding flocks, hearing roosters call and answer down and across the valley.

At night I use their ‘all’s well but I am half asleep’ call when I check them at night, so as not to scare them. They mumble it back to me as a soft
‘GWARK, gu, gu, gu, GWARK’.

Chickens can learn some English commands. The most useful is ‘Here, chook, chook, chook.’

And they are wonderfully instinctive.
Coming home to roost, lining up to get let out in the morning, squatting on command.

And they are family and social. A hen and her little band of chickens following on are a thing of wonder.