Semmelweis Effect: The Truth About Why We Resist Change

The Semmelweis effect is a metaphor for the reflex-like tendency to reject new evidence or information because it contradicts our existing beliefs, norms, or paradigms. It comes from Hungarian physician Ignaz Semmelweis, who discovered that childbed fever mortality rates fell tenfold after doctors disinfected their hands in between patients. Semmelweis’ procedure saved countless lives but, despite the overwhelming empirical evidence, his fellow doctors rejected the hand-washing solution to disease transmission.

While there is uncertainty regarding the background of the Semmelweis effect, it has been used in literature and manifest in human behavior. The reflex stems from cognitive biases. The confirmation bias, stating that we overvalue information which is consistent with prior beliefs or values, and the authority bias, underlining our tendency to be swayed by authority figures. Combined, this goes to explain why Semmelweis‘ hand-washing practices were not implemented: (1) the existing belief was that diseases spread mainly through “bad air” and that childbed fever is caused by inherent weakness, not unclean hands; (2) the hand-washing proposal challenged prevailing norms; (3) Semmelweis’ ideas were put forth before medical professionals made the link between germ and disease, and the leading physicians had the view that gentlemen’s hands did not transmit disease; (4) his idea was innovative and so challenged the common consensus, making for frustration in the medical community.

As a more recent example, take the case of COVID-19. The recognition of airborne transition was delayed despite evidence indicating aerosol spread. The focus of the World Health Organization was on droplet transmission since almost all infectious diseases spread that way. It was not until December 2021 that the WHO recognized airborne transmission, showing the challenge of shifting entrenched beliefs, especially when the prevailing understanding aligns with social norms. Integrating innovation into existing frameworks is a significant challenge.

Consider the Semmelweis reflex a knee-jerk reaction to everything disruptive and counterintuitive. It’s natural and a textbook case of how existing beliefs can delay the acceptance of beneficial innovations. People resist change. Anything that challenges our worldview, values, or competence is likely to be rejected. Humans are inclined to maintain the prevailing reality. Opting in for this lens makes us aware by prompting us to think of why we might be rejecting or accepting ideas prematurely.

The Semmelweis effect is a double-edged sword. It encourages open-mindedness, helping teams and individuals remain receptive to new knowledge. By questioning automatic rejection, it promotes critical, deeper thinking that can encourage accurate decision-making. Overcoming the reflex empowers individuals to take on disruptive technologies and methods that result in significant breakthroughs. Whereas falling for the reflex perpetuates outdated practices and stagnation. In fields like medicine and technology, dismissing such solutions can be life-and-death, literally.

Real life implications of the Semmelweis reflex:

• Medicine: historical examples, like the case of Semmelweis himself, should remind medical professionals to stay on top of novel solutions and remain open to new practices, even when they challenge standing conventions;

• Technology: innovators face skepticism when introducing disruptive technologies, so recognizing Semmelweis reflex aids individuals and organizations to adopt new tools;

• Education: teachers and institutions might resist new teaching methods and technologies, so adopting a more open-minded approach is critical to improve student outcomes and awareness of the Semmelweis effect is one step in the right direction;

• Business: leaders who recognize this inclination in teams and create a culture of innovation can encourage their teams to explore unconventional ideas without fear of immediate dismissal;

• Social: movements advocating for equality or sustainability, for instance, often face resistance because of the Semmelweis effect, and overcoming this reflex is crucial for progress.

How you might employ the Semmelweis effect as a thinking tool: (1) cultivate intellectual humility, acknowledging the possibility of being wrong and remaining open to new evidence, especially when it contradicts established beliefs; (2) separate your ego from your ideas, as conflating your personal identity with what you practice or believe can further reinforce the Semmelweis reflex; (3) encourage debate, fostering a culture where disagreement and questioning the status quo is normal and even emphasized; (4) conduct pilot tests instead of outright rejection, implementing small-scale trials to gather evidence prior to making sweeping decisions; (5) reflect on resistance, asking “Why am I rejecting this?” and “Is my rejection due to a discomfort with change or evidence?”; (6) stay informed, as keeping up with advancements and research in your field will clearly highlight when you are dismissing an idea due to the Semmelweis reflex as opposed to objective assessment.

Thought-provoking insights. “Every great advance in science has issued from a new audacity of imagination.” is a saying by John Dewey, emphasizing the importance of embracing new ideas, even when doing so means challenging conventional thinking. “We’ve always done it this way.” should now act as a cautionary tale about the mindset behind the reflex, often used to resist change. Galileo’s heliocentric theories are a prime example in history of ideas facing vehement opposition, illustrating how disruptive innovations are and will be rejected initially. Recognize this bias. If you want to be a disruptor, an innovator, a trailblazer. You must. Else you won’t change.