Biodemographic study of a central Apennine area (Italy) in the 19th and 20th centuries: Marriage seasonality and reproductive isolation

This study investigates seasonality of marriages and reproductive isolation in six long-isolated communities in the central Apennines (Italy). It had two objectives: (1) the identification of an Apennine biodemographic model in comparison with mountain communities of other regions, and with non-Apen nine communities in Abruzzo, and (2) to identify the possible effects of th e drainage of Lake Fucino (1854-1876) on that area. Marriages in this regio n show two very stable seasonal patterns: one is typical of sedentary rural societies, with summer migrations and marriages preferentially celebrated in the winter, and the other has marriages that are strongly concentrated i n the summer months, i.e. between 75%, and 93.5%, of marriages were celebra ted between June and October in these communities in the 1800s. These were traditionally pastoral communities with winter transhumance of the flocks a nd their shepherds towards the lowlands of southern Italy. In both groups, restrictions imposed by the Catholic Church do not seem to have affected th e timing of marriages. Indeed, economic factors related to work activities seem to have had more influence. Concerning reproductive isolation, the res ults show high rates of endogamy: between 85% and 98%, in both the 19th and 20th centuries. Rates of consanguineous marriages were between 5% and 20%, and those of isonymous marriages rarely exceeded 9%. The coefficient of in breeding alpha shows that there was a delayed, limited period of increased consanguinity in the few decades around the turn of the century. This is di fferent from the national situation, and thus could be a consequence of the Lake Fucino drainage.