Yeah, it's interesting to see who likes to be picked up, who likes to jump up on their own terms, and who's friendly but doesn't really like to be pet at all. My chicks are 7-weeks and I probably spent anywhere from 30 minutes now while I'm teaching full-time up to (can't believe I'm saying this!) two hours a day on late summer days. They're just so fun to play with! They associate me with food, so they always come running.
I picked them all up twice a day because I carted them inside and outside for weeks before they moved to their coop, so I think that helped.
I would say all of my chicks are "friendly"--but some are really affectionate and calm while others are more stand-offish and not as quick to hop up in my lap.
I find the Roos hands-down more friendly, willing to explore, and willing to be pet. Wonder if this will change--my pullets are typically the more shy & reserved chickens.