Content Warning: This section of the guide contains discussions of maternal mortality.

The chapter begins with the story of Ignaz Semmelweis, a Hungarian physician in the mid-19th century who confronted the rampant issue of childbed fever in maternity wards. Semmelweis observed that women attended by doctors and medical students had significantly higher mortality rates compared to those attended by midwives. Through meticulous observation, he deduced that doctors were transferring infectious material from autopsies to the maternity ward. By implementing a simple hand-washing protocol using a chlorinated solution, Semmelweis drastically reduced mortality rates. However, despite the clear success of this intervention, Semmelweis faced resistance from the medical community. The authors use this example to assert that entrenched beliefs can impede the adoption of effective solutions.

The narrative then shifts to the introduction of seat belts in automobiles. While seat belts have undoubtedly saved lives by reducing fatalities in car accidents, their introduction also led to an unintended consequence known as risk compensation. Some drivers, feeling more secure, began to drive more recklessly, potentially offsetting the safety benefits of seat belts. This phenomenon underscores the complexity of human behavior and how safety measures can sometimes lead to riskier actions.