When I raise my chicks, I handle them daily from the first week. Some are super friendly and want to cuddle. Some are shy and don't want to be touched. But they all get gentle handling at least once a day. When they are 8 weeks old I start working on respect with the cockerels. I walk up to them, and expect for them to move away. If they don't, they get gently pushed. After a week they figure it out. They're still babies, so nothing aggressive -- just gently teaching the rules, every day. I also randomly but regularly hold their head (and when they get older, their comb and waddles), push them to the ground and gently "stand on them" with my hand (almost no pressure -- I don't want them feeling that they can't breathe, or that this hurts), hold both feet in one hand and set them on my lap on their side while using my other hand to rub under their wing or on their chest or move their head around while being held on their side or back. I start with them early, but only after they know me well and don't consider me a predator. I never do anything that is rough or painful or even scary. Just gently dominant. It's an every day thing and they grow up knowing that I'm the dominant rooster of the group.
When they're 12 weeks old, they are separated from the pullets and put in the bachelor pasture. At that age they aren't old enough to be a threat to my adult roosters (who are really good with chicks -- don't do this if your roosters are too aggressive), but they're old enough to run and hide. I call it "going to rooster school." Because the adults will seriously put them in their place when needed, and I watch how they do it. Basically, they do exactly what I described above, but much rougher. The youngsters are expected to step aside for the king, and if they don't they are body slammed to the ground, the comb is grabbed and the head is shaken until the chick can run away. They're not injured, just intimidated. They learn quickly not to do anything disrespectful, until the hormones hit in full force. Then they lose their mind and forget everything they learned for 1-3 months. That's the young and dumb stage. Some will handle the testosterone poisoning well, make a few bad choices, get put in their place and then it's over. Others will have so much drive and not give up for a long time, or ever. That's when you have to make sure that not a single transgression ever goes unpunished. One success will embolden him for 100 attacks. Most of my boys will get that look in their eye before the attack -- that expression of glazed over aggression from the testosterone surge. That's the best time to act, before they strike. Reach down, pick them up, roll them on their back, hang them by their feet for 15 seconds, grab their comb and move their head around for a minute, move into them with aggressively scuffing feet -- whatever works best to redirect the attention of that particular cockerel, and get his mind off attacking you, and refocus his brain on the fact that you're the dominant rooster. Once the attack has already started you're trying to clean up after the car crash -- stopping the attack is like preventing the accident in the first place. When they're this age I always carry a large towel with me. If I'm not able to redirect their behavior, or if I can't catch them because they're stalking me instead of attacking (which is absolutely not allowed - I will run at them aggressively if they're stalking me), then the towel keeps them from landing the first blow. A cockerel that is able to land the first blow and doesn't redirect will fight and fight. Engaging him in a fight only promotes the aggressive behavior, even if they lose every time. Like the adult rooster, you've got to prevent him from landing any blows, and teach him that you're the boss when he gets twitchy. Hitting him with a thick towel when he's coming at you isn't painful and doesn't cause injury, but it deflects his attack and prevents him from being able to get to you. A cockerel that can't land even a single blow will eventually give up, and continued towel swats will cause him to run from you, which is what you want at this stage.
Once the hormonal hell passes in a few months, most cockerels that have been taught respect, and have not been able to assert their attempted dominance over you, will mature into sweet, trustworthy cocks. I never judge them for going through their teenage months -- that's how their body is made, and they can't help it. But I don't tolerate it if they can't adjust to the ebb and flow of their hormones once they get passed this hormonal flood. I tried the alternative method on many, many roosters years ago -- keeping them super tame, being their friend, never showing dominance -- just love. It worked on a few that had no innate desire to be the top dog anyway, but usually the sweetest, tamest roosters matured into fearless, dangerous cocks later in life. They had never been taught respect as youngsters, and saw no reason to give it as adults.
I have a beautiful, huge Speckled Sussex cock who is 4 years old, 11 lbs of muscle. He was late maturing, so his hormonal hell hit 2-3 months after the rest of the group. Oh he was a challenge, possibly having more drive because he was older and stronger than the others when they went through the same stage. But we eventually got through it, and he matured into the most amazing cock -- totally trustworthy with me, but he doesn't tolerate other roosters AT ALL, so he has his own pasture away from other males. Last week he was in his pasture and a hen walked by the fence. It's full out breeding season here, and he was 1000% focused on this hen. I needed to move him to another area, and I walked up behind him to pick him up. He didn't realize it was me, being totally focused on her, and I unfortunately didn't do anything to bring his attention to me before touching him. When my hand touched him he almost exploded with aggression. His beak was clamping on my fingers when I said, "You don't really want to do that, do you?" in a dominant voice. He immediately let go of my finger, backed away from me a few feet, sat down and made several little cooing noises. He was so sorry. It was totally my fault for not letting him know it was me behind him instead of another rooster. I let him stay back for a minute, then pulled a treat out of my pocked and called him to me. I kneeled down, gave him the treat for being a good boy and respecting me by backing off, then asked him to jump in my lap for snuggles. He is a pet and I love him dearly, but he is still a rooster. I can't ask him to understand my values of empathy and kindness to others, as that is not how he's hardwired. His brain is hardwired to be either the dominant rooster, or the subordinate rooster. That's what is there to work with. Accepting that will allow you to develop some wonderful, totally trustworthy males, but it takes a plan of consistency to make it happen if you've got a boy that has any drive at all.