Holding chicks really has a limited affect on chicken behavior with people, and almost none at all with other chickens. Chickens are not like puppies and kittens, where affection when young, and growing up together makes for strong bonds. Chickens are just not that way.
Generally speaking, space and how that space is set up is the most consistent reason for birds not getting along. And what people can over look, is that what was enough space when chicks, is not enough space when full size.
Letting them out of a too small set up for periods of time, also has almost no effect on behavior. I think people think of this as taking the dog for a walk. Again, chickens are just not that way.
Some birds, some breeds can take a little overcrowding, and some cannot.
Always solve for peace in the flock.
Mrs K