Ignaz Semmelweis, a 19th-century Hungarian doctor, noticed something curious: the mortality rate of women delivering babies in his hospital was markedly different in two different wards. Mothers who had their babies delivered by doctors died 3x as often as women whose babies were delivered by midwives.

After painstaking research, Dr. Semmelweis determined there was only one possible explanation for the difference: the doctors routinely handled cadavers while the midwives did not. He concluded that there must be some sort of “infective material” from the cadavers that was being transferred from the doctors to the women during birthing.

To test his theory he instituted the practice of the doctors washing their hands in a solution of chlorinated lime prior to delivering babies and the death rate in the physician delivery ward dropped to match that of the midwife ward.

Case closed? Nope. “Despite the clear drop in the death rate, his theories were completely rejected by the medical community at large. In part, doctors were offended by the idea that they were killing their patients. Others were so hung up on the perceived deficiencies of Semmelweis’s theoretical explanation that they ignored the empirical evidence that the handwashing was improving mortality.” Source.

To say that Dr. Semmelweis was shunned by the medical community is a massive understatement. As the medical community continued to ignore his pleas for them to wash their hands, his behavior became erratic and extreme as he tried to convince his fellow doctors to adopt his protocols. To shut him up a peer doctor lured Semmelweis to a mental asylum under the guise of visiting a patient and he was locked up against his will. He lived out the rest of his life in the asylum and died at age 47. It took 20 years for Semmelweis ideas about hand washing to take hold after Louis Pasteur and others proved germ theory.

The reflexive rejection of new evidence because it conflicts with accepted practice is referred to as the “Semmelweis Reflex.”