The Languages of Pao

The Languages of Pao is a science fiction novel by Jack Vance in which the Sapir-Whorf Hypothesis is strongly true.

In this novel, the Emperor of a planet called Pao hires a consultant to make his people less wimpy. The consultant uses his unique family resources and social institutions to create several new languages. These languages make warriors, aggressive merchants, technological geniuses and so on, which then come to life and create conflicts where peace existed before.