Brachycephalization and debrachycephalization in Bulgaria during 20th century

Abstract

The present paper is a continuation and extension of a review made in 1989 in an attempt to combine and compare data of different studies, including cephalic dimensions and cephalic index in Bulgarian adult men and women from the end of 19th to the end of 20th century. There were seven nation-wide studies in Bulgaria during 20th century and few local ones. In some of them means of cephalic index is published, in other - only head length and head breadth averages and cephalic index has been estimated by us. The data are analysed by year of birth, not by year of investigation. This analyse presents that cephalic index in Bulgarians increases until the generation born around 1935-1940, than a process of debrachycephalyzation begins. In men born in the end of 19th century the cephalic index was about 79-80, in these born around 1940 - about 83 and falls to 81-82 in men born in 1950-s. In women cephalic index is usually about 0,5% higher. The brachycephalization and the debrachycephalization are due mostly to changes in head breadth, whereas head length remains relatively stabile. Secular changes do not occur uniformly in all regions - in some of them debrachycephalization can not be found until 1991. Despite the secular changes a large territoriopopulation heterogeneity in cephalic index remains which goes back at least to 18th-19th century. This heterogeneity is probably due to the different components in the ethnogenesis of Bulgarian people and its ethnographic groups.