A Hi So Thai is usually a person whose family background is very wealthy, not recent wealth but wealth gained over a prolonged period of time. They have or have had high ranking family members in the government system or military. Holiday homes in Hua Hin or a similar spot, the times when they get stopped by the Thai police they just need to make one phone call before they are back on their way doing whatever it is they shouldnтАЩt be.
They may also have a lot of respect and pull in a certain town or city, due too there family name and what they ancestors have done in the past. A Hi So Thai would also have a strong family legacy, connected to well respected and well recognised people of the public spreading over a series of decades.