Because people in India believe that there is an awe-inspiring god on their child's head. If you touch the child's head, the god will be taken away and the child will have bad luck. Advent.
India has many different cultures and taboos from my country. In Indian tradition and religion, what Indians particularly don’t want is for others to touch their children’s heads. They think that is Being severely slighted and disrespecting them. Sometimes, it will cause a lot of trouble. In India, even if the elders express love for their children, they are strictly forbidden to touch the top of the child's head, because the gods on the top of the head will not bless the child. Therefore, you must not touch the head of an Indian child.
In Indian habits, when they are thinking about a problem, they usually inadvertently and slowly shake their heads from side to side. They are not in the habit of shaking their heads to express disagreement. Indians are very taboo about using their left hand to pick up items. In their perception, the left hand is unclean and inferior. At the same time, they don't like others touching their children's heads. In particular, it must be noted that when they express their agreement to something, they shake their heads, or tilt their heads slightly to the left first, and then immediately return to the original position to express "yes".
If you travel to India and visit Indian temples, you must follow their customs. You cannot wear anything made of cowhide. Even handbags made of cowhide should not be brought into the temple. These will violate the prohibitions, because in Hindu beliefs, believers worship cows as sacred objects and cows cannot be used as food. Slaughtered, even things made of cowhide don’t want to be seen.
Different countries have different beliefs. We can only respect their beliefs, their customs and etiquette, just like you must not touch a child's head in India.