The Semmelweis reflex is a metaphor for the reflex-like tendency to reject new evidence or new knowledge because it contradicts established norms, beliefs or paradigms.
The term originated from Ignaz Semmelweis, who discovered that childbed fever mortality rates could be reduced ten-fold if doctors would wash their hands (we would now say disinfect) with a chlorine solution between having contact with infected patients and non-infected patients. His hand-washing suggestions were rejected by his contemporaries.


