jealousy

jealousy... hhhmmmm, i bet you all know what it feels like, that twisting bitter feeling in your gut, the feeling that makes you feel like tearing the person you are jealous of into tiny little pieces to be tossed to the dogs.
i do, but i try not to let it influence my actions towards a person. i know that jealousy is bad but is there any possibilities that maybe it might come in useful?
think about it, we have this particular emotion, what do we do with it?
some use it as a tool for revenge,some become a tool of revenge but don't even realize it, some ignore it and some simply show it to the world without shame.....
like my friend in school, she got all A's and yet she still beats herself up (mentally) because someone else has higher marks than she has... she feels jealous of the person and uses it as a tool to actually do better, i have another friend who is jealous of other people's friendship and tries to steal friends away to attract attention, one might also be jealous of a friend of coupling with an ex-boyfriend and that jealousy parts their friendship and lay waste to their once golden friendship...then the best friend found out why her friends broke up with the her ex and the two friends be friends once again...
but why are some people more prone to feel jealousy than others?
is it genetic?
is it upbringing?
is it something to do with your horoscope?
or is it a mixture if 2 or more of these elements?
and should we use this jealousy to gain? or do we ignore it and be jealous free?
or both? depending on the situation?
i have no idea why i'm writing this down in the first place!
jeez now you know how nuts i really am!
k.bye...