Considering those three, they look at a bunch of parameters and present different alternative theories that attempt to predict how they influence how someone will react to fear appeal:

• the amount of fear that it is intended to arouse (since the actual effect depends on many factors beyond the message itself). There are different theories for how the level of intended fear relates to action: Low levels of fear are not expected to have large effects on action in either, but in one theory high fear should lead to high motivation, and in the other moderate fear should lead to highest motivation, whereas high fear works to paralyze the recipient, who will then try to avoid being exposed to the message, or disregard it alltogether.
• the presence of efficacy statements, i.e. messages reassuring the recipient that they are capable of doing the recommended action, or that those actions will have an effect on reducing the problem they are afraid about. Only if action seems do-able and like it will reduce the problem, a fear appeal should lead to strong action; but there are different theories on whether fear appeals without efficacy statements will backfire or just be less effective than those that include one.
• depticted susceptibility and severity, susceptibility being about the personal risk being stressed, and severity being about the negative effects that inaction would have. The theory here is that high susceptibility should improve intentions and behaviors, high depicted severity should improve attitudes, and a combination of both should improve all the above.
• the recommended behavior: are we talking one-time or repeated (one-time should be easier to convince people to do); is it framed as preventing losses or as potentially gaining something (preventing losses should be more successful); does it mention death (should make things more urgent, but also should make people work on counteracting their anxiety by working on their self-esteem), is it relevant for self-esteem (as in supporting a behavior that is good for your self-esteem, or discouraging from one that is good for your self-esteem because of its harm in other areas), or are there time delays (if it is very short-term, people are more likely to go into denial than to do something)?
• the audience, for example women and members of collectivist groups tend to be more focussed on prevention of harmful outcomes than men and members of individualist groups; people in the early stages of a process should be more likely to reconsider than people who are already much more invested, unless, in a conflicting theory, those people are already invested in change itself and thus prepared to change even more?

“(a) fear appeals are effective at positively influencing attitude, intentions, and behaviors; (b) there are very few circumstances under which they are not effective; and (c) there are no identified circumstances under which they backfire and lead to undesirable outcomes.”

The authors find that fear appeals are most effective when the message is written in a way that relatively high amounts of fear are intended, if it includes an efficacy message, makes both susceptibility and severity of the danger conveyed in the message very clear, targets only a one-off behavior rather than a repeated one, and when the audience is mostly female. What this study explicitly does not answer, however, is the influence of the source of the fear appeal (is it trustworthy? Perceived as benvolent or biased?) and the way fear appeals are delivered (e.g. graphic or audio? Social vs mass media?).

It does also not become clear how exactly this translates into teaching. Of course that was never the goal of the article, but that’s the lens through which I read it, specifically how should we deal with fear appeals when we teach about climate change or biodiversity loss? If fear appeals work best on mostly female audiences, what does that mean for our mostly male students at LTH? Are fear appeals still a promising way to go then? And we probably want repeated and sustained action, not just a one time effort? But even with those questions still open, it is good to see confirmed that the positive, constructive messages, stressing what individual and collective action people can take, that “we can fix it“, are the way to go, and that — and this part I did not realize before — the fear appeal should be very concrete, focussing on the risk of personal harm and what that would look like. This will definitely influence how I think about teaching sustainability, thank you, Léa!