You can compare personal space to the Thai custom of men and women touching each other. In Thailand a man can touch a man, or a woman can touch a woman, but it is very rude for a man to touch a woman. The man must. Always stand about twenty centimeters away from the woman. It’s as if there is a wall around the woman’s body, and the man is not allowed inside. Whenever you meet a foreigner, always stand as far away as a Thai man would stand from a Thai woman, and then you won’t have to worry about getting inside the foreigner’s personal space.