Wait... I read this discussion and this give an aggrement to my experience. When I was a little child, I usually used my left hand to do anything, but, in my primary school, I was tought to write exclusively in right hand (involving anything from my teacher giving an extra cake when I behave nicely, and she grab my left hand and say "Don't do this this is the baadddd hand" everytime I try to write with it). The result is: I was able to write nicely only with right hand (i still capable to write clearly readable with my left, but the quality is poor compared to my right writing (I have a really nice handwriting, everyone said that.. eheh)), and the right hand was better to do some soft work (such as titration and place small objects on microscope), but when I got into a fight or playing sports that need strength, I use the left, because the muscles on my left hand is definitely bigger than the right..... well, I play tennis, badminton, and basketball mostly with my left.
So, that handedness... is decided by who are teaching you about doing something...
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