Thais regard the head as the highest part of the body both literally and figuratively. As a result, they do not approve of touching anyone on that part of the body , even in a friendly gesture. Similarly , if you watch Thais at a social gathering , you will notice that young people go to considerable lengths to keep their heads lower than those of their elders , to avoid giving the impression of "looking down" on them. This is not always possible , of course , but it is the effort that counts.