People who write with their left hand make up 10% of the world population, and whether the child will be born as the backside can be predicted before birth. Regardless, today in many countries children are forced to write right-handed, and in numerous languages, such as English word right, “right” also means “right” and “right.”
According to the child's position in the womb can determine whether the child was born left-handed, but it is not entirely genetically determined, so that identical twins have the same genes may have different dominant hand. What is the likelihood that the child will be born as hander depends on which hand write their parents. If the father says with lev hand, and his mother with a right, then the child has a 17% to be left-handed and vice versa - if the mother writes with lev and the father the right, then the probability is 22% to be left-handed. If both parents are right-handed, then there are 10% chances of the child to be left-handed, while if both are left-handed, there are 20% chance the child is left-handed.
Numerous theories dealing with the question of why evolution maintains steady-hander in the whole population. The Videoton below refer to activities that are better for those who write with lev hand, and that those who write with the right hand.