Touching someone’s head is a gross violation of etiquette in countries with mostly Buddhist population. It is believed that the head is the receptacle of the soul, so touching it is forbidden for everyone except spouses and other family members.
The rules of etiquette around the world vary considerably, sometimes even within the same country. For example, what is considered polite in the north of China, may be considered impolite and ignorant in the southern regions of that country.
