i watched this thing on one of the science channels about serotonin and baboons. apparently the dominant male of the troop had very high levels and submissive baboons lower levels. When they increased serotonin in submissive baboons there dominance increased and as alpha males lost their positions their levels dropped in response. The scientists messed with this back and forth and the same results followed. i can not take ssri's as they make me aggressive. i am a submissive yet get very dominant and challenging on anything that increases my serotonin. i like ian was saying had an abusive childhood, yet in my household as i reached adolescence stood up to one abuser(she became intimidated) and stood toe to toe with the other who would not capitulate and i moved out at 15. i find that i am calmer when in the presence of an alpha who is not abusive and i get aggressive in the presence of one who it. it would seem that it all plays a part in why i am submissive, and also when i am not why that too.