In which country would it be a grave insult to touch someone on the head?

In Thailand, it is considered a grave insult to touch someone on the head. The head is regarded as the most sacred part of the body, representing a person's spirit and dignity. Thus, touching someone's head, even in a friendly manner, can be seen as disrespectful and intrusive. It's important to be mindful of this cultural norm when interacting with Thais.