Did Premodern Wars Impact Sex Ratios at Birth? The Case of 19th-Century Basque Country.

ABSTRACT: This study examines the impact of pre-moder wars on sex ratios at birth. Specifically, it investigates whether wars involving premodern weaponry and more limited destruction increased stress for pregnant women such that the resulting hormonal changes in their bodies may have led to a decrease in the ratio of live-born boys to girls. To address this question, we analyzed all baptismal records from the Basque Country during the 19th century, encompassing nearly 1.2 million individuals. Our findings confirm that the First Carlist War (1833-1840) exercised the most significant demographic impact on the region. However, all wars resulted in variations in demographic behavior, reducing in sex ratios at birth by around 1%. This effect is even more pronounced when focusing on the main conflict zon

SUBMITTER: Marco-Gracia FJ 

PROVIDER: S-EPMC12417252 | biostudies-literature | 2025 Jun

REPOSITORIES: biostudies-literature