Zonta, L.A. et al (1995) Early selection and SexComposition in Italy: A study at the Region Level.

PURPOSE: The purpose of Early Selection and Sex Composition in Italy is to try to investigate whether socioeconomic, cultural, or Biological factors still influence the sex ratio at birth in four Italian regions.
APPROACH: The author of this article, L.A. Zonta, along with his partners P. Astolfi and L. Ulizzi, chose four Italian regions with different degrees of industrialization and socioeconomic levels to study environmental differences in the sex ratio. The studied the still birth rate and the relations between newborn viability and sex composition as a function maternal age and educational levels. The author looked at studies that had been completed as early as 1662 by J. Graunt that reported an excess of male births (415). They realized that many researchers have investigated patterns of sex ratio deviations from the 1:1 ratio however; many of these investigations do not include a high number of factors that seemingly affect sex ratios. Zonta gives a short description of pr...