In the title, the division of the word is linked to a game of terms: "Nations" underlines our being totally immersed in continuous contamination of styles. This research, which ranges from the contamination of styles in artistic productions to the observation of how many different elements make up our lives over time, is based on the reflections that the American anthropologist Ralph Linton proposed to his students in his "First anthropology lesson", extracted from one of his articles from 1937.