Fear is a potent emotion that arises when we perceive a threat. It sets into motion a wide range of bodily responses to ultimately deal with the threat (i.e., fight, flight, or freeze). Unlike other animals, who mostly experience fear in the present, humans have an unlimited capacity for being scared, thanks to their ability to reflect on the past and imagine the future. As a consequence, scaring people has long been recognized – by health professionals, policy makers, politicians, and parents – as a powerful tool to evoke behavior change. People are encouraged to quit smoking through gory pictures of cancerous lungs, prompted to address climate change through images of floods and forest fires, and, now, urged to comply to Covid-19 guidelines through graphs of exponentially increasing infection rates. But how effective are fear appeals? More than six decades of psychology research provides some answers.

Scare tactics
Fear appeals, also called scare tactics, typically consist of a threat communication combined with, ideally, a means to terminate the threat (i.e., quit smoking, stop flying, keep your distance). A widely held belief is that the more intense the fear the threat message arouses, the more compelling the message it conveys. Although this may be true, research suggests increasing fear does not necessarily make people more likely to act. The extent to which people address their fear by taking action depends on whether they are able to do so, and whether they think their behavior will resolve the threat. Thus, the effectiveness of a fear appeal relies perhaps less on its potential to arouse the emotion as on whether people believe themselves capable of dealing with the source of the emotion: so much so that if no effective means are available (or perceived to be available), all the appeal will do is leave the individual in an unresolved state of anxiety.

The law of diminishing returns
Such a state can only last for so long, so people address the situation by trying to deal with the fear rather than the threat. Researchers have warned about the law of diminishing returns: the fact that with repeated exposure people habituate to the communicated threat (prompting public figures to suggest making scarier messages), and display risk normalization. A related issue is what has been called the “finite pool of worry”: the fact that increased concern about one risk may lessen concern for other risks). This can result in the paradoxical situation where someone finds themselves worrying about a threat , at the cost of other threats. But see this recent study showing that the Covid-19 pandemic did not seem to affect UK citizen’s climate concerns.

Persuasive intentions
Another unintended effect of repeated use of fear appeals is that the practice may erode trust in the authority that conveys these messages. People have become increasingly aware of the persuasive intentions of the media, commercial parties, and governmental institutions. When people realize they are being appealed to through their emotions, rather than via objective argumentation, this undermines their trust in the messenger. This is particularly problematic when there is a need for sustained and consistent risk communication, as in the case of climate change, or the current Covid-19 pandemic.

Raising defenses
Finally, some individuals may be more receptive to fear appeals than others, and a considerable body of evidence suggests that, ironically, an intense fear appeal will not convert the non-compliant citizen. This is because people raise their defenses, in particular when the desired behavior conflicts with self-relevant goals. In response to billboards with gruesome traffic accidents to prevent drunken driving, some people may claim that their drinking does not affect their driving skills, and thus the message does not apply to them. Neuroscientific evidence suggests, for instance, that smokers systematically avoid confrontation with compulsory graphic visualizations on smoking packaging.

Situational differences
To summarize over six decades of psychological science, when promoting protective action among the public, arousing strong fear can be an effective means to direct behavior, but the impact depends on certain conditions. Moreover, it is important to realize that appealing to fear is often unnecessary, and may even do more harm than good. Especially when the situation calls for prolonged action willingness, as in the case of the current pandemic, the most important principle is to communicate risks in an accurate and comprehensible manner, along with clear guidelines for how people can mitigate such risks.