Normalcy Bias

“Normalcy bias” defined as a cognitive bias that leads people to disbelieve or minimize threat warnings. Normalcy bias has also been called analysis paralysis, or the ostrich effect, and by first responders, the negative panic.  

Normalcy bias explains why, when the volcano Vesuvius erupted in 79 AD, the residents of Pompeii watched for hours without evacuating. It also explains why thousands of people refused to leave New Orleans as Hurricane Katrina approached, and why at least 70% of 9/11 survivors spoke with others before leaving the World Trade Center. Officials at the White Star Line made insufficient preparations to evacuate passengers on the Titanic and people refused evacuation orders because they underestimated the odds of a worst-case scenario and minimized its potential impact. Similarly, experts connected with the Fukushima nuclear power plant were strongly convinced that multiple reactor meltdowns could never occur.

Amanda Ripley, author of The Unthinkable: Who Survives When Disaster Strikes – and Why, identifies common response patterns of people in disasters and explains that there are three phases of response: Denial, Deliberation, and the Decisive Moment. With regard to the first phase, described as Denial, Ripley found that people were likely to deny that a disaster was happening. It takes time for the brain to process information and recognize that a disaster is a threat. In the Deliberation phase, people have to decide what to do. If the person does not have a plan in place, this creates a serious problem because the effects of life-threatening stress on the body (e.g. tunnel vision, audio exclusion, time dilations, out-of-body experiences, or reduced motor skills) limit an individual’s ability to perceive information and make plans. Ripley asserts that in the third and final phase, described as the Decisive Moment, a person must act quickly and decisively. Failure to do so can result in injury or death. She explains that the faster someone can get through the Denial and Deliberation phase, the quicker they will reach the Decisive Moment and begin to take action.