A recent example of irrational fear occurred after the 2011 Japanese earthquake that led to a tsunami and near nuclear meltdown. Of all the lives lost, most deaths were caused by the tsunami and none was caused by radiation. Yet, people feared the radiation more than the tsunami. Potassium iodine pills are the recommended treatment for people within a 10-mile radius of a radiation leak. However, there was a run on potassium iodine pills at pharmacies along the West Coast of the United States, over 5,000 miles away, where the estimated doses of radiation from the Japanese reactor leak was about the about the same a person might receive during ONE round-trip international flight. In addition, these same people continue to live along an area most likely to be affected by an earthquake or tsunami.
People like to think that humans think logically and rationally, but research into the field of risk perception has proven this incorrect. People have two inputs that affect their perceptions, logical thoughts from the brain and instinctive feelings from the gut, which are many times in conflict. Perceptions are also effected by emotional associations and mental shortcuts. Rather than assessing a risk by objective, verifiable data, such the odds of the risk occurring, people tend to rely on subjective, subconscious calculations. What you have heard from friends, read recently on the internet, and what is occurring around you at the time carry more weight in your risk assessments than do cold, hard facts.
Our instinctive, gut reactions that originate in the amygdala, the part of the brain that control emotions, have helped us avoid an attack from an enemy who charges out of the surrounding trees and bushes by giving us a split-second of lead time that allowed us to move away from the attack, but these gut reactions do not work when we are walking down a street with hundreds of different vehicles, buildings, and people carrying out all types of activities. Rarely does anything stand out as a threat.