Whether a person is right-handed or left-handed results from________.

Some people are right-handed and some are left-handed. No one knows the reason why a person becomes right-handed or left-handed. (11) It is not true that it is caused by the way in which his parents educate him. In other words, a person is born to be right-handed or left-handed. Moreover, the left-handed and the right-handed "think" differently. Having to use the hand you’re not used to can be very upsetting.
    One day I tried an experiment: changing hands while eating rice with chopsticks. Being a right-hander, I hoped it would not be too hard for me to take the food with my left hand. Soon after I started, I realized I didn’t know what I was doing. (12)So I moved in front of a big mirror, in order that I could observe my actions clearly. (13) Looking at myself in the mirror, I found I looked like a man who had never used chopsticks. I grew more and more nervous and finally I had to give it up.
    My experience shows, being forced to use the hand one is not used to affects a person’s mind. So we should not try to change a left-hander to a right-hander. Some people still think being left-handed is bad, but luckily this idea is changing.