Abstract
The aim of this thesis is to determine by a downward movement the part that can be ascribed to the demography and socio-economical differences to be found on the boundary zones between France and Spain (Basque area, Catalonia) and between France and Italy (south of Alps). Thus boundary effects have been located only below and not above treatments. The purpose is to distinguish the role played by the boundaries from other elements that are also factors of differenciation. Nationalities, regional and local tendencies, distances between individuals, road-systems and relief are parts of these elements. Hence an approach studying space and regions has been favoured. And the methodology used here involves techniques related both to continuity (space autocorrelation, variograms) and to discontinuity (national belonging autocorrelation, image analysis).