In your experience were they chiefly from day one, or did it come as they got older?
Well, it wasn't a cuddle fest from Day 1 with anyone but the little white cockrel from my Avatar, Mr Peanut. I think because we bonded on the ride home, he knew that he could trust me from that point on. He was on my shoulder that same night, snuggling.
(I don't advise or recommend that, by the way. Had it gone wrong, it could've gone VERY wrong...for me. But I had a sense about him & I was right.)
Everyone else learned that affectionate behavior in varying degrees, according to their personalities and opportunity within the flock. My other roo, a strikingly handsome Barred Rock (if I do say so myself) was raised from about 8 weeks by us & while he wasn't about human interaction during the daylight hours, he was perfect with the Ladies. He was agreeable at night about getting pets, cuddles & being tucked in on his roost & I was never afraid of him. For those reasons, he was perfect, though NOT a cuddler or lap chicken AT ALL.
I couldn't have made a better chicken if I'd had the power to create him myself. Same with my Mr Peanut.
It simply takes working with them, lots of flock interaction and a shameless amount of treats. And healthy treats are best. I used to chop iceberg lettuce & put it in bowls for my 1st flock. My 1st flock had a cuddle bug hen & she was not interested in eating anywhere but on my lap, so we shared snacks & cuddles while the rest of the girls were in the yard & pecking around. When my lap chicken had had enough cuddles, she'd jump down & we'd hunt bugs together with the flock.
No one else was interested in cuddles until she passed away. (That was horrible, by the way & is still THE worst part of having a flock, just so you know...) When there was a vacancy on my lap, one by one, someone stepped in to fill it. My 2 hold outs to cuddling would sit on the perch next to me but never wanted to sit on me. I still counted that as a win.
Long answer but I hope that it shows that just because they don't jump right into cuddles that doesn't mean that they won't at some point. It also means that you have to accept how far they're comfortable going & just be part of their flock. And young ones are trying to figure out food sources v predators v pecking order. You're incredibly large by comparison, so they're working on not freaking out & running away from you.
They'll get there. And a mealworm or choice bug caught & offered when calling them by name will help them to associate their name with food. (But don't fib! There are times when my well trained ladies will refuse to go home, even now. I go inside, get my bag of raw, unsalted sunflower seeds, call them, rattle that bag o gold & walk toward the coop. Never had one who could resist! If I rattle the bag or shake a bottle of freshly caught bugs, they get rewarded for listening to me when they do what I ask.)
Hope this helps.
