“For Better, for Worse”: The Role of Siblings in Survival and Biological Well-Being in Rural Aragón (Spain) in the Twentieth Century

Marco-Gracia, Francisco J. (Universidad de Zaragoza) ; López-Antón, Margarita

Resumen: This article examines the evolution of the role played by the number and gender of siblings in the survival and biological well-being of individuals in rural Spain during the twentieth century. Our aim is to test how two fundamental theories – the cooperative breeding hypotheis and the resource dilution hypothesis – about how the number of siblings affect the individual come together in this area of study during a period of economic, health, and social transformation. We used a sample of 19,331 individuals born between 1900 and 1979 from 14 rural villages, for whom data on sibling count and various family and environmental variables are available. Using these data, we ran several statistical models to discover the effects of siblings on survival. In addition, we studied the long-term effect of siblings on height using height data from 2,783 male conscripts. Our results show that the number of siblings positively influenced survival, either through the cooperation of older siblings in the care of their younger brothers and sisters or through parents exhibiting higher offspring survival abilities. However, increased reproductive success may come with a disadvantage. The biological well-being, as measured by height, of male conscripts was significantly lower among individuals with more siblings in the early decades of the study. Conversely, in the later decades, the negative relationship between sibship size and height was not statistically significant when the number of living siblings was fewer than five.

Idioma: Inglés

DOI: 10.1017/ssh.2025.26

Año: 2025

Publicado en: SOCIAL SCIENCE HISTORY (2025), 1-29
ISSN: 0145-5532

Tipo y forma: Article (Published version)

Área (Departamento): Área Hª e Instituc.Económ. (Dpto. Economía Aplicada)