The scientific controversy surrounding consanguineous marriages:

a debate about its possible influences on the intellectual and moral of the children of these unions

Abstract

On June 30, 1865, at the solemn anniversary session of the Imperial Academy of Medicine, the members of that institution proposed another theses competition for the year that was beginning. Among the motivating questions listed, one asked about “What influence can consanguineous marriages have on the intellectual and moral of the human species?” Only one article was submitted to the proposed question, authored by Luís Vicente de Simoni, who emphatically postulates the harmful effects that consanguinity had on the offspring of the related couple. Thus, Simoni took sides in the scientific controversy surrounding consanguineous marriages, joining the ranks of the anti-consanguinist school. This quarrel generated a heated debate among doctors of that century and was part of another larger controversy: that of the possibility of hereditary transmission of pathologies. The pages of Brazilian medical journals from the 19th century are important traces of these debates as they allow us to compare the main arguments of the divergent schools of both controversies. However, for this article to focus on the (anti)consanguine debate, it is necessary to delve into the issue of heredity due to its relevance as a field in which the consanguinist debate arises.

The possible effects of consanguinity on the “intellectual” of the offspring takes a prominent place in the anti-consanguinist argument that saw a series of mental sufferings as being attributed to consanguineous marriages. This article debates the association between consanguinity and mental suffering and the weight of this argument in the consanguinity controversy that influenced the second half of the 19th century.