I have a bunch of 5-6 week olds that I got at 2 weeks of age. They were scared for a bit....I would talk to them and visit their brooder often and put my hand in with treats. It didn't take long for the oldest to realize "the hand" was a good thing, and it would run over and peck my fingers

Soon, they all were! After a week, I would gently pick them up to put them outside, for playtime, and then pick them up and bring them back to the brooder. When I wanted them to come, or I had a treat to offer, I would call them "chi, chi, chi."
It seemed
very sudden, they all gentled down....I moved them to the coop and now when they are being picked on, they run to me and hide around my legs. If I call "chi, chi, chi" they come running! If I put my hand down, they come and stand in front and wait for me to pick them up

If I sit on the coop steps, they perch on my lap, or one likes to get on my shoulder
They also like a little breast rub, they bump each other out of the way! It's a very nice feeling
I never intended for this to happen, I just wanted to be able to examine them when needed...