As part of a survey of the biological history of Alpine populations, the lineages of all the families of the Vallouise valley (a French ‘department’ of the Hautes Alpes) have been reconstructed over several centuries. The genealogies have been included in a computerized population record, known as ‘Vallouise in the Briançon area (14th–20th centuries)’, using the French–Canadian programme Analypop. Most of the professions of the family heads were included in the files. In this study, various profession groups were identified and their descents determined over successive generations. In this mountain area, where over 92% of marriages took place among relatives during the 19th century, the profession groups modulated their descents according to chosen strategies, sometimes with considerable differences among groups but with a remarkable consistency of behaviour. Moreover, there was weak interpenetration in the descents of each profession at both the 2nd and 3rd generations.