Jenny Thomann-Koller (14 September 1866 - 5 February 1949) was a gynecologist, pediatrician, and Head of Internal Medicine at the Schweizerische Pflegerinnenschule mit Spital (Swiss Nursing School with Hospital) in Zurich.
In her dissertation, Beitrag zur Erblichkeitsstatistik der Geisteskranken im Ct.
Zürich.
Vergleichung derselben mit der erblichen Belastung gesunder Menschen u.
dergl.
(Contribution to the Statistics of Heritability of Mentally Ill People in the Canton of Zurich.
Comparing these with the Hereditary Burden among Healthy People), published in 1895, she introduced a control group which challenged the then-popular theory of degeneration and eugenics.