Ironically my first roo wasn't friendly as a hand raised chick and was terribly aggressive as a roo; he was great with the girls but not humans.Thanks--- I've read so many threads about how the favorite cockerel turned aggressive, people ask, what in the heck happened???? But, aware of that, I had not made a pet of the aggressive grandfather, I was always hands off.
There's really no way to be sure until it is too late, since behavior changes over time and with changing flock dynamics as well.
I want to wait until at least I know how many of the 4 Spitzhaubens are boys. That could be another month, at which time, it will be the monthly poultry swap day.