this is just my opinion and really not worth a whol.e lot ..but i figure the more you handle your birds as babys and as they grow the less aggressive they will be with you.i think this is true with all breeds ..but now if a stranger came in to the pen they may be a little more flighty or even aggressive twards them ..i think they see strangers as a new member and are trying to set their standing in the pecking order ..i no my granddaughter handled them as babys alot but once they were grown and in the pen and she went in the pen for the forst time they went after her fingers ..my wellies are kind of skiddish but not aggressive at all..
like i said just my opinion..lol