Named after a doctor whose life-saving hand-washing theories were rejected, the Semmelweis reflex describes the tendency to ignore new evidence that conflicts with existing paradigms. Accepting the new idea would force an admission of past error, which is psychologically difficult. This is a crucial barrier to overcome when selling new ideas internally.

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Even Donald Hoffman, proponent of the consciousness-first model, admits his emotions and intuition resist his theory. He relies solely on the logical force of mathematics to advance, demonstrating that groundbreaking ideas often feel profoundly wrong before they can be proven.

Beyond testing hypotheses, real-world experiments serve a crucial social function: reducing employee fear of change. By co-designing experiments with skeptics to test their specific assumptions, innovation teams can quell fears with data, turning organizational resistance into buy-in.

We instinctively resist things that violate our established mental categories. The visceral rejection of drinking fresh water from a pristine toilet demonstrates this powerful bias. Disruptive innovations often fail not because they are bad, but because they force people to break a well-defined mental category, causing cognitive dissonance.

The human mind rejects ideas that are too novel. Effective communication and innovation should be grounded in the familiar, introducing only about 20% new information. This principle, from designer Raymond Loewy, helps make new concepts intelligible and acceptable.

Applying the machine learning concept of a "learning rate" to human cognition suggests that when a core assumption is proven wrong by a single counterexample, one should radically increase their learning rate and question all related beliefs, rather than making a small, incremental update.

The gap between AI believers and skeptics isn't about who "gets it." It's driven by a psychological need for AI to be a normal, non-threatening technology. People grasp onto any argument that supports this view for their own peace of mind, career stability, or business model, making misinformation demand-driven.

To counteract the brain's tendency to preserve existing conclusions, Charles Darwin deliberately considered evidence that contradicted his hypotheses. He was most rigorous when he felt most confident in an idea—a powerful, counterintuitive method for maintaining objectivity and avoiding confirmation bias.

Once people invest significant time, money, and social identity into a group or ideology, it becomes psychologically costly to admit it's wrong. This 'sunk cost' fallacy creates cognitive dissonance, causing people to double down on their beliefs rather than face the pain of a misguided investment.

Germ theory was resisted by the medical establishment and adopted last by doctors. The shift was driven by outside cultural forces, like the 'Rainy Day Club,' that created social proof and new public expectations. This shows that profound change is often forced upon institutions from the outside in.

To get your team to adopt a new strategy, you as the leader must present it with absolute conviction. Any hesitation you express will be amplified by your team, leading them to reject the idea because they sense your lack of belief.

The Semmelweis Reflex Explains Why We Reject New Ideas That Contradict Established Beliefs | RiffOn