Joe, What do you mean by aggressive? How is this aggressiveness exhibited? How many years of experience w/ bees do you have?
Is "aggressiveness" a trait that is passed on through the drones or through the queen? When a hive exhibits agressivness (highly defensive stinging) we usually requeen. Probably because that is the easy thing to do. But I don't know where the genes come from. Maybe from both, I don't know.
"It's not what you look at that matters, it's what you see." Henry David Thoreau, Mark B