This study is about the principles for constructing polite speech. We describe and account for some remarkable parallelisms in the linguistic construction of utterances with which people express themselves in different languges and cultures. A motive for these parallels is isolated - politeness, broadly defined to include both polite friendliness and polite formality - and a universal model is constructed outlining the abstract principles underlying polite usages. This is based on the detailed study of three unrelated languages and cultures: the Tamil of south India, the Tzeltal spoken by Mayan Indians in Chiapas, Mexico, and the English of the USA and England, supplemented by examples from other cultures. Of general interest is the point that underneaath the apparent diversity of polite behaviour in different societies lie some general pan-human principles of social interaction, and the model of politenss provides a tool for analysing the quality of social relations in any society.