Beware Of The Semmelweis Reflex

Do we suffer from the Semmelweis Reflex?

The Semmelweis reflex is a metaphor for a type of human behaviour charactised by the tendency to reject new evidence or new knowledge because it contradicts established norms, beliefs and other established paradigms. Daniel Kahneman calls it theory-induced blindness – an adherence to a belief about how the world works that prevents you from seeing how the world really works.

The bias takes its name from the reaction of the medical community against the findings of Ignaz Semmelweis, a Hungarian obstetrician, who showed that hand-washing by physicians in an antiseptic solution before delivery reduced puerperal sepsis in the mother by 90%.

In mid-19th-century hospitals in Europe puerperal fever was common and there was a high mortality (10-35%) but by 1847, Semmelweis had discovered that the incidence of puerperal fever could be drastically cut by hand-washing with a chlorinated lime solution.  He made the audacious and until then, unheard of, suggestion that doctors wash their hands between doing an autopsy and delivering a baby.

His research showed that in the Vienna General Hospital, the doctor’s wards had three times the mortality of the midwife supervised wards but the of practice of hand-washing reduced puerperal mortality to below 1%.

This new-fangled idea of washing hands between touching cadavers and examining pregnant women would eventually save thousands of lives and subsequently earned him the description of “saviour of mothers”.

Despite this, Semmelweis was ridiculed and his hand-washing suggestions were rejected by Professor Johann Klein, the medical director and his first boss in Vienna because his observations conflicted with the established scientific and medical opinion of the time. Klein stripped Semmelweis of his university position and repeatedly blocked his career progress.

Unbelievably, Grant et al noted that despite 150 years of evidence, hand-hygiene practices by healthcare workers remain unacceptably low.

The chances are the Semmelweis effect is contaminating your school. This will probably include left and right brain thinking (which is not supported by any evidence), learning styles (just a load of old rubbish) and the idea we only use 10% of our brain (nonsense).

Neurolinguistic programming still has its supporters despite the scientific evidence declaring it a pile of tosh. There are of course plenty more including multiple intelligences, ability grouping, the Learning Pyramid and Maslow’s Hiearchy of Needs.

Despite little or zero evidence to say they have any impact, these myths and legends are still kicking about our classrooms and school corridors and we suffer from the Semmelweis reflex every time we refuse to face the facts and instead rely on our prejudice or unfounded beliefs.

Can we avoid the tendency to reject new evidence or new knowledge simply because it contradicts our worldview?

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