Vaccination and betrayal aversion

How do people analyze risks to determine the best course of action?

Imagine that you were given a choice of two different rental apartments, and you were planning to make your decision based on which offered the most protection from death in a fire. The first apartment had an older smoke alarm and a 2% risk of fire related death; the second apartment had a newer smoke alarm with a 1.01% chance of fire related death. All other factors being equal, those who are fire averse will choose the apartment with the newer technology and the lower risk of death, right? Not necessarily and the reason is a widespread but seldom noted phenomenon, betrayal aversion.

The apartment example is taken from a recent paper by Gershoff and Koehler, Safety First? The Role of Emotion in Safety Product Betrayal Aversion, published in the January issue of the Journal of Consumer Research. The authors note that some risks are apparently more frightening than others.

Consumers often face decisions about whether to purchase products that are intended to protect them from possible harm. However, safety products rarely provide perfect protection and sometimes “betray” consumers by causing the very harm they are intended to prevent. Examples include vaccines that may cause disease and air bags that may explode with such force that they cause death. … [T]his study examines the role of emotions in consumers’ tendency to choose safety options that provide less overall protection in order to eliminate a very small probability of harm due to safety product betrayal…

Gershoff and Koehler’s asked study participants which apartment they preferred, having explained that smoke alarms differ in risk of death, but also in the risk of malfunction:

Some participants were told that in the event of a nighttime fire due to the usual causes, occupants in the apartment equipped with Alarm One had a 2% chance of dying while occupants in the apartment equipped with Alarm Two had only a 1% chance of dying. However, they were also told that the wiring of Alarm Two was such that it sometimes causes electrical fires that increase the risk of dying in a nighttime fire by an additional 0.01%. In other words, Alarm One was associated with a 2% risk of death and Alarm Two was associated with a 1% + 0.01% (betrayal) risk of death.

Most participants of the study chose the apartment with Alarm One even though it had double the increased risk of fire death. That’s because most participants the tiny risk of “betrayal” (product malfunction) much more frightening that the much larger risk of actually dying.

Why did the risk of product betrayal loom so large in the minds of study participants?

It is not surprising that consumers consider the risk of betrayal when choosing among safety devices. The mere possibility of betrayal threatens the social order that enables us to trust the safety infrastructure of our society, causing intense visceral reactions and negative emotions toward the betrayer. Unfortunately, these strong negative emotions toward a potential betrayer may also lead people to take unwise risks…

It is this visceral reaction that causes people to make irrational decisions about vaccinating their children. When parents balance the much larger risk of a child dying from a vaccine preventable disease against the tiny chance of a child being injured by the vaccine, they regard the possibility of product betrayal with out-sized horror. And because they are horrified by the tiny risk, they paradoxically choose the much larger risk. Ironically, they actually think that they are “protecting” their children by embracing the much higher risk of death from disease.

That’s because reaction to risk depends on emotion as well as rational analysis:

Research on how people evaluate risky options points to the importance of … the emotional system. Studies show that people commonly make judgments and decisions under uncertainty based on nonprobabilistic rules, visceral urges … and gut feelings. [The] risk-as feelings hypothesis … argues that feelings such as worry, dread, and fear drive decisions in ways that cannot be reconciled with an analytical assessment of the underlying risks…

Gershoff and Koehler note that betrayal aversion has important implications for public health policy:

… Various government agencies are charged with protecting public safety and general welfare. These agencies frequently issue safety standards on such important matters as seat belt usage in cars, helmet usage on bicycles, and vaccinations for public school children. Policy makers, who generally prefer alternatives that maximize overall safety, need to be sensitive to the possibility that members of the public will find some of those alternatives emotionally repugnant. Indeed, large portions of the public may act in ways that put them at increased risk…

Interestingly, the authors do not suggest that people should be encouraged to dismiss betrayal aversion:

… If the negative consequences of safety product betrayals reach beyond the immediate harm .., then one cannot say that consumers’ safety product preferences should rely on probability of death comparisons alone. A rational person may justly believe that eliminating the collateral damage that betrayals may cause, including the emotional toll and damage to the social order, is worth trading for a small increased risk of death.

That may be true, but many people do not realize that their judgment is shaped by betrayal aversion. If, after careful consideration of the actual risks, some people elect to accept the higher risk of harm from vaccine preventable illness over the much smaller risk of harm from vaccines, they have every right to do so. But in order to carefully consider the risks, people need to realize that their emotional reaction to product betrayal may be clouding their assessment of the magnitude of the risks.