Resumen: This article uncovers the existence of discriminatory practices in pre-industrial Spain by examining the fate of twins. The analysis of the complete parish registers of a small rural area (17 villages) shows that female twins were discriminated both at birth and during infancy and childhood. Not only the sex ratio of twins at baptism was extremely unbalanced, but discrimination continued throughout infancy and childhood and resulted in female excess mortality, despite that males are biologically more vulnerable. Although their extremely high mortality rates question the idea that twins constituted an exogenous shock to family decisions due to their impact of the family budget, studying twins helps shedding more light on discriminatory patterns because many families prioritised male twins to enhance their survival chances. Idioma: Inglés DOI: 10.1080/1081602X.2022.2039878 Año: 2022 Publicado en: HISTORY OF THE FAMILY 27, 4 (2022), 658-678 ISSN: 1081-602X Factor impacto JCR: 1.0 (2022) Categ. JCR: HISTORY OF SOCIAL SCIENCES rank: 8 / 34 = 0.235 (2022) - Q1 - T1 Categ. JCR: FAMILY STUDIES rank: 40 / 46 = 0.87 (2022) - Q4 - T3 Factor impacto CITESCORE: 2.0 - Arts and Humanities (Q1) - Social Sciences (Q2)