I will assume that this question is from the myth, "The World on Turtles back". If it is not I apologize. But if it is, the left and right twins are the exact example of ying and yang, good and bad. The left-handed twin represents evil, war, and the 'bad' aspect of human nature. The right-handed twin represents being responsible, correct, and what we would consider the 'good' aspect of human nature today. Relating it to myself, I would see the right-handed twin as who I would always try to be, and see the left-handed twin as completely evil and who I would try to avoid being like that twin any way I could. But it really depends on what your own perspective of human nature is, because really anyone is possible of being good or bad.
