Marriage behaviour in the Alpine Non Valley from 1825 to 1923

Background: The study is part of a research project on the marital structur e of mountain populations from the Eastern Italian Alps. Little is known ab out marriage patterns in this Alpine area. Aim: The aim of the study is to evaluate the extent of reproductive isolati on in some communities of the Non Valley (Trentino, Italy) and to investiga te its microgeographic and temporal changes over the period 1825-1923. Subj ects and methods: 4518 microfilmed marriage records from registers of seven parishes of the Non Valley were used to analyse the following: endogamy ra te, inbreeding calculated both from dispensations and from isonymy, repeati ng pairs of surnames in marriages, isonymic relationships. Results: The results show notable variability among parishes in the levels of endogamy (40-73%), inbreeding (alpha: 1.9-4.57; F-t: 0.0073-0.019) and s ubdivision (RPr/RP: 0.5-1.3). The values are relatively stable over the cou rse of a century, apart from a rise in inbreeding indicated by dispensation s and a slight decrease of endogamy at the beginning of the 20th century. I sonymic relationships reflect geographic proximity between populations, wit h minimum changes through time. Conclusions: Variations in the level of reproductive isolation within the N on Valley are consistent with the different geographic characteristics and population sizes of the settlements. Comparison with data obtained from pre vious studies in the Eastern Italian Alps shows that the values of the inve stigated biodemographic indicators are in line with the geography and altit ude of the area. The slight differences in temporal trend of endogamy and i nbreeding can be correlated with different migration patterns.