Benedict-Augustin Morel (1809–1873)

Benedict-Augustin Morel’s theory of degeneration dominated French psychiatry for almost a century after its publication in 1857 (1) because it provided psychiatry with a convincing biological explanation about how abnormal mental conditions were acquired.

Combining concepts of acquired traits becoming fixed in germ plasm, drug toxicity, and hereditary transmission, Morel described a progressive generational degeneration starting with neurosis in the first generation, mental alienation in the next, and imbecility in the third, culminating in sterility in the fourth and final generation. What was being passed on was not a specific pathology but a susceptibility of the nervous system to disturbances originating from “overindulgence” of toxic substances such as alcohol.

Morel’s theory provided a parsimonious explanation for the etiology of insanity and social deviance (2) and generated research programs to demonstrate how paternal drinking affected progeny (3) and created the background for eugenics programs to improve humans through sterilization of those considered inferior (4).