They do calm down with age, but personally, I don't keep aggressive birds. If he's aggressive enough to scalp a hen, he goes. I breed for temperament as much as anything else.Is it like a cockerel that they are a bit overzealous when they first start and then calm down? They just turned 5 weeks on Wed. Or is it something that if rough they stay that way. Once I know for sure who is female and what color eggs they lay I will be selling them.