It's not necessarily just about either being an as*hole or not...That is not the ONLY way it can effect ones personality....
Basically put, What is anger or aggression? It's our emotions, which in essence is our personality....So it really effects our emotions...
Which also goes to say everyone is different and it will effect them differently...My only point was, however it MAY effect you....You will DEFINITELY see personality changes on certain compounds on high enough dosages....Whether the person realizes it or not...