My children and I believe in the Bugs Bunny/Daffy Duck method from the Snowman episode: "I will hold him and hug him and I will call him 'George'....." Our roosters use the "limp noodle" defense in return. If they go limp and floppy enough, the kids will put them down. My brother (their Uncle Josh) taught them to say, "Somebody needs a HUG!" Josh's chickens scatter when he says it, lol.
When I bought my breeder quality Ameracuana boys at a chicken swap, I was worried about how they would react to my children. That was in between me watching them in the rearview mirror as they tried to fly on the air entering the camper shell through the front window. My son picked up the cockeral we named Nugget. Nugget rolled his eyes as if to say, "Oh great, another kid!" Needless to say I was very happy with my purchase. Recently I spoke to the lady that raised them. She has a son younger than mine and lots of children that visit. She was also happy to hear that chickens she raised were behaving well.
I tell people to think about training a dog. If you left a puppy in a cage and only threw food at it once a day, it would be an unhappy, mean dog. Chickens don't have quite the same social needs as a dog, but they need time with us to learn what we would like them to do.
Back off when I come in the gate with your food.
Make noise when something is wrong.
Behave while I'm picking up eggs. Or cleaning up your yard.
Don't get between my feet while I'm trying to put your feed down.
Here's hoping some of this will help!