In Thai culture, taboo includes touching someone's head or pointing at your feet.

An excerpt from the article 31 facts about Thailand

The head is considered the most sacred, and the feet are the lowest part of the body. Thai customs include respect for elders and superiors (by age, position, monks, or certain professions). Part of Thai spiritual practice is respect for ancestors. Thais have a strong sense of social hierarchy, which is reflected in many honorifics. They also have a strong sense of hospitality and generosity.