I have a young BR roo that has been handled extensively since day one. He turned aggressive (pecking, challenging me upon entering his space) suddenly as he hit adolescence. I used nonviolent techniques from BYC posters to nip this in the bud before it became a habit. We had a few "encounters" (me pushing him down on ground, carrying him, following him) to sort out the pecking order and now he is quite the gentleman. I pick him up daily, hand feed treats. I remain vigilant as he is not fully mature. But creating and confirming a habit of good behavior makes sense to me.