Theodore M. Porter


On his book Genetics in the Madhouse: The Unknown History of Human Heredity

Cover Interview of June 18, 2018

In a nutshell

Genetics in the Madhouse examines the study of human heredity historically, from the ground up. The gene eventually comes into the story, as anyone would expect, but in an odd and inglorious role. That is partly because the story takes off more than a century before anyone ever spoke of “genes” or “genetics,” about 1789. I focus on problems and places that mattered for those who first labored to establish rules of hereditary transmission in humans. Their chief concern, as I have tried to demonstrate, was the terrible problem of madness. The science of human heredity first took form in insane asylums.

Then, as now, heredity was a data science. The treatment of mental illness underwent a radical reform beginning in the 1790s. The new moral treatment aspired not to drive out demons but to cultivate the elements of rationality that were retained even by the mad. Old forms of treatment were now condemned as senseless and cruel. Insanity, the reformers proclaimed, was a disease, whose victims were not to be blamed. The new asylum, replacing the old “madhouse,” was to be scrupulously ordered and regulated. The public expense to support these new institutions demanded scrupulous patient records, as well as financial ones; annual reports were organized mainly around statistics. The most important of these numbers, apart from demographic information on admissions and outcomes, was the statistics of causes: appropriate tables made heredity visible and even measurable.

It seems that the idea of inherited insanity was not really new, not even in 1789. The tables of causes, which almost always showed heredity in a lead role, were based mainly on what family members told the asylum doctors in an admission interview. Inheritance of insanity was a familiar folk belief. About 1840, passive recording began to give way to determined investigation of family members similarly affected. Instead of simply tallying the causes supplied to them, doctors constructed increasingly elaborate tables to link causes with disease forms and cure rates. By this time, a few doctors were using institutionalized patients as a point of entry for investigations of insanity as a family disease. Later in the century, they began calculating probabilities of mental illness in the offspring based on the health status of the progenitors. The documentation of causes now took on increasing urgency. Insanity rates did not diminish in the face of new treatment ideals but expanded unremittingly right through the nineteenth century and beyond. Soon it was impossible to believe that medical treatment could turn back the insanity explosion. Eugenics (as it came to be called), the effort to combat insanity by preventing its victims from reproducing, arose very early as part of the program.

All of this took place with very little involvement of scientific academies or universities. About 1900, when Mendelian genetics and a new biological statistics appeared on the scene as rival approaches to the medical and statistical science of heredity, their practitioners looked around and discovered that asylum doctors already commanded the expertise to analyze their unmatched data reserves.