Genetics in the Madhouse: The Unknown History of Human Heredity

nature  |  Who founded genetics? The line-up usually numbers four. William Bateson and Wilhelm Johannsen coined the terms genetics and gene, respectively, at the turn of the twentieth century. In 1910, Thomas Hunt Morgan began showing genetics at work in fruit flies (see E. Callaway Nature 516, 169; 2014). The runaway favourite is generally Gregor Mendel, who, in the mid-nineteenth century, crossbred pea plants to discover the basic rules of heredity.

Bosh, says historian Theodore Porter. These works are not the fount of genetics, but a rill distracting us from a much darker source: the statistical study of heredity in asylums for people with mental illnesses in late-eighteenth- and early-nineteenth-century Britain, wider Europe and the United States. There, “amid the moans, stench, and unruly despair of mostly hidden places where data were recorded, combined, and grouped into tables and graphs”, the first systematic theory of mental illness as hereditary emerged.

For more than 200 years, Porter argues in Genetics in the Madhouse, we have failed to recognize this wellspring of genetics — and thus to fully understand this discipline, which still dominates many individual and societal responses to mental illness and diversity.

The study of heredity emerged, Porter argues, not as a science drawn to statistics, but as an international endeavour to mine data for associations to explain mental illness. Few recall most of the discipline’s early leaders, such as French psychiatrist, or ‘alienist’, Étienne Esquirol; and physician John Thurnam, who made the York Retreat in England a “model of statistical recording”. Better-known figures, such as statistician Karl Pearson and zoologist Charles Davenport — both ardent eugenicists — come later.

Inevitably, study methods changed over time. The early handwritten correlation tables and pedigrees of patients gave way to more elaborate statistical tools, genetic theory and today’s massive gene-association studies. Yet the imperatives and assumptions of that scattered early network of alienists remain intact in the big-data genomics of precision medicine, asserts Porter. And whether applied in 1820 or 2018, this approach too readily elevates biology over culture and statistics over context — and opens the door to eugenics.