Every rooster is an individual though there is really nothing set it stone. You’ll read hand feeding makes them mean. BS. I do believe there is some truth to young stags/cockerels that are bold enough to not show the normal flightiness toward you when young. I believe they have a slight tendency to be more aggressive later on. With that being said it’s not a high enough percentage like others claim. I would just pay closer attention to that particular bird. Some people really just shouldn’t have roosters. Hell some people shouldn’t have chickens period.