Many other cultural differences are not easily detected by outsid- ers, like the ways in which people v reality, their understanding of how to think and behave, the covert institutions which organize their differences often manifest these deeper differences, lives. Behavioral but the connection may not always be obvious. People in one ethnic group often make mistakes dealing with those of another when such assumptions, and the behavior which stems from them are not understood But no individual differences like these by themselves are sufficient cues to ethnicity. People judge by configurations of cues seen in con text. If someone is speaking good Standard Thai but wearing a Mien vest, the vest will likely be more telling than the language in signal ling ethnicity. That is true unless the cues are conflicting, as when the person is standing in front of a stall where Mien vests are sold to Thai tourists in the night market at Chiang Mai. And all of this is compli cated by the fact that most ethnic groups are culturally diverse, as with ethnic Thai who range from village farmers to King Bhumibol. Ethnicity, therefore, is enormously elastic, a configuration or ges talt without objective criteria, its content differing from society to society. People in all societies apparently sense it, however, and res pond in some degree to perceived differences in culture which they associate with inheritance and/or territoriality. In many cases their own ethnicity is the soil in which their whole being is nourished, the foundation of their sense of belonging. But the fact of ethnicity alone is not what gives it great power in so many situations. Rather, the meaning and function which people ascribe to it provide its moving force. In the following sections of this chapter we go on to look at some of the dynamics of ethnicity and ethnic interplay in Thailand, especially those that relate to language.