BISTOPS 2022 Special Section

Trigger warnings—alerts which typically advise people about the negative nature of the material to follow, and state or imply they may have an adverse reaction to it—are common on college campuses (Kamenetz, 2016; National Coalition Against Censorship [NCAC], 2015). But their use is controversial (American Association of University Professors, 2014; Lukianoff & Haidt, 2015; Wyatt, 2016). For example, in early 2023, the student assembly at Cornell University passed a resolution that would require their instructors to administer trigger warnings about potentially upsetting class material, but soon afterwards the university’s president rejected the resolution, citing concerns about academic freedom (Rosman, 2023). Providing trigger warnings (or one of their close cousins, such as content warnings, content notes, and other such advisories that precede negative material) may seem harmless, even courteous. These warnings are intended to allow people—particularly those who may be grappling with posttraumatic stress disorder (PTSD) or who have had negative experiences related to the material—to make an informed choice to avoid the material, or to engage with it on their own terms, and thereby reduce the distress they might otherwise experience (e.g., Gust, 2016; Manne, 2015; Manning & Wace, 2016; NCAC, 2015). But a growing body of psychological research suggests that not only do trigger warnings fail to have their intended effects—they may increase people’s distress (e.g., Bridgland et al, 2019; Jones et al., 2020; Sanson et al., 2019). Here, I review the latest addition to the body of empirical work on trigger warnings, by Kimble and colleagues (2023). Then, drawing on their findings and the wider literature, I outline three compelling reasons to forego the use of trigger warnings.

In a series of studies, Kimble and colleagues have addressed the extent to which students with a history of trauma are “triggered” by material of the sort they would encounter in a classroom (Kimble et al., 2021; Kimble et al., 2022; Kimble et al., 2023). That is, they have asked: how much does reading a negative passage lead potentially-vulnerable students—those who have experienced an event similar to that in the passage, or who report levels of PTSD symptoms indicative of disorder—to experience (a) a disproportionately greater level of distress, or (b) a worsening of their PTSD symptoms over time, relative to their peers with no such vulnerability? Across these studies, they found that students who had experienced a similar event either did not report greater distress than their peers or else recovered quickly from a somewhat higher level of distress and reported no worsening of their PTSD symptoms. Moreover, they found that although students who had probable PTSD sometimes reported greater distress than their peers in absolute terms, they showed the same trajectory of elevation and recovery to baseline, and no worsening of their PTSD symptoms. Kimble and colleagues (2023) conclude they have found no evidence of students being triggered by experiences like those they might have in a college classroom. They finish by advising that college instructors should choose whether or not to administer trigger warnings on a case-by-case basis.

However, these data fit with the idea that trigger warnings are designed to solve a problem that is, at least in college classrooms, extremely rare. That finding alone is a good reason to dispense with trigger warnings. Yes, some students come to college with a history of trauma, even PTSD—and those students deserve to get the help they need to resolve their symptoms. And yes, those students may find upsetting material upsetting—but Kimble and colleagues’ findings suggest they are no more likely to experience increased, ongoing distress than are their peers with no such history.

This pattern of transitory distress in the face of a negative experience, followed by a recovery to baseline, is reminiscent of two other bodies of work. First, trauma researchers sometimes use the “trauma film paradigm” as an analog for exposure to trauma, exposing people to negative film clips, and then examining their analog PTSD symptoms about that clip over time (for reviews, see Holmes & Bourne, 2008; James et al., 2016). In these studies, people commonly report PTSD symptoms similar to those that people experience after real traumas, but at much lower levels and for shorter durations (Holmes & Bourne, 2008; James et al., 2016; see also, Stirling et al., 2023). Second, outside the lab, researchers have demonstrated that when people are exposed to a real traumatic event, the majority either never experience clinically significant distress or recover from distress with no lasting symptoms of clinical significance (for a review, see Galatzer-Levy et al., 2018; see also, Rothbaum et al., 1992). Taken together, these studies suggest that when people are exposed to negative material, regardless of their trauma history, they are likely to recover to baseline quickly. Whether a trigger warning hastens or delays their recovery is a question worthy of further research (cf. Bridgland & Takarangi, 2021).

Given that there is no systematic evidence of students being “triggered” by negative material and good evidence that people usually recover from negative experiences in the absence of trigger warnings, instructors need not invest their pedagogical energy in deciding whether and how to administer such warnings. What is more, looking to both Kimble and colleagues’ own data, and the wider literature on the consequences of trigger warnings, there are at least three additional reasons why college instructors should not administer trigger warnings.

People Do Not Use Trigger Warnings to Avoid Potentially Distressing Material

Proponents of trigger warnings suggest that one way people like to use the warnings is to avoid engaging with material they could find distressing (e.g., Manning & Wace, 2016; NCAC, 2015). Of course, given that such avoidance perpetuates anxiety, a clinician might argue that enabling such avoidance is unhelpful (for a meta-analysis, see Littleton et al., 2007). But do people actually make use of trigger warnings to avoid negative material? A growing body of research suggests the answer is no (e.g., Bridgland et al., 2023; Bridgland & Takarangi, 2022; Jones et al., 2020; Kimble et al., 2021; Kimble et al., 2022; Kimble et al., 2023; Sanson et al., 2019).

Instead, this work demonstrates that people rarely use trigger warnings to avoid the material that will follow. For instance, Kimble and colleagues have repeatedly found that, when given the choice to read a warned-about article vs. a more neutral alternative, just 3–6% of students choose the alternative—even when, as in this most recent study, the warned-about material matched a traumatic experience from their own past (Kimble et al., 2021, 2022, 2023). Studies that did not offer an explicit choice have found similarly low rates of avoidance. For example, across a series of experiments that my colleagues and I conducted, between 0 and 2% of people who began an experiment withdrew upon receiving a warning (Sanson et al., 2019), and in a study that specifically recruited people with a history of trauma, < 1% withdrew after receiving a warning (Jones et al., 2020). Finally, in an experiment designed to mimic a social media setting, in which people could choose whether or not to uncover a negative photo under a “sensitive-content screen,” just 15% of people left the negative photo covered. Furthermore, their choice was not related to their mental health (Bridgland et al., 2022). Taken together, these studies fit with the idea that people rarely make use of trigger warnings to avoid negative material, even when they have mental health problems—which suggests that there is little point in providing them in college courses for that purpose.

People Do Not Report Less Distress After Getting a Trigger Warning

Proponents of trigger warnings suggest another way that people might use trigger warnings, namely as a prompt to mentally prepare themselves so that they are less distressed by the material that follows (e.g., Gust, 2016; Manne, 2015). But in one study, when people imagined coming across a trigger warning and were then asked what strategies they would use to cope with the warned-about material, they reported similar strategies as people who did not imagine a warning (Bridgland et al., 2023). Consistent with this finding is evidence that trigger warnings do not reduce how distressing people find negative material: Many studies—spanning a range of samples, media, topics, and measures of distress—have found that people who see a trigger warning before they are exposed to negative material are about as distressed as people who do not (e.g., Bellet et al., 2020; Boysen et al., 2021; Bridgland et al., 2019; Jones et al., 2020; Sanson et al., 2019). In other words, there is a body of evidence to suggest that trigger warnings do not have their intended benefits for people who face rather than avoid negative material.

The same conclusion applies to data from studies that have examined the extent to which trigger warnings reduce distress among people with a history of trauma or PTSD—those for whom the warnings are often intended (Jones et al., 2020; Kimble et al., 2023; Sanson et al., 2019). In one of these studies, which recruited a large sample of people with a history of trauma, those who received a warning found the negative material just as upsetting as those who did not. Among those who reported high levels of PTSD symptoms (indicating they were likely to currently have the disorder), those who received a warning found the negative material slightly more upsetting than those who received no warning (Jones et al., 2020). Similarly, my colleagues and I recruited a sample from the general population but then examined the differences between warned and unwarned subjects who (a) reported experiencing any past trauma, (b) reported high levels of current PTSD symptoms, or (c) reported experiencing an event of the same type as the negative video they had been randomly assigned to watch. In each case, we found the degree of distress reported by warned subjects immediately afterwards was similar to those who had not been warned (Sanson et al., 2019).

In their most recent study, Kimble and colleagues further investigated this issue. They chose materials that focused on a rape, and—though they did not include an unwarned control condition—compared the reactions of subjects who had vs. had not reported a history of unwanted sexual contact (Kimble et al., 2023). As they report, those with a history of any unwanted sexual contact had a trajectory of distress over time that was similar to those without such a history. Although those with a history of more serious sexual assault reported more immediate distress than those without such a history, both groups showed the same return to baseline over time. Of course, from these data we cannot know what the trajectories of unwarned subjects might have looked like. But these findings fit with the idea that students with a relevant history of trauma did not uniquely benefit from a trigger warning. Taken together, these studies suggest that when people are exposed to negative material, regardless of their trauma history, a warning will not reduce the height of their peak distress and may even increase it. Therefore, again, the data suggest there is little value in administering trigger warnings about college course material in an effort to reduce students’ distress.

People Find Trigger Warnings Themselves Distressing

The evidence reviewed so far suggests that trigger warnings are, at best, ineffective. But given that they are well-meant and appreciated by at least some students (Bentley, 2017; Cares et al., 2019), what is the harm in continuing to provide them? The answer is that, ironically, the warnings themselves may cause distress. Several studies have compared giving or not giving people a trigger warning and then—before exposing them to negative material—asking them about their expectations about the material or measuring their level of negative affect or symptoms of anxiety (e.g., Boysen et al., 2021; Bridgland et al., 2019; Bruce et al., 2023; Jones et al., 2020; Sanson et al., 2019). These studies reveal that, rather than being helpful or even inert, trigger warnings themselves worsen people’s negative expectations about the material that is to follow and lead them to feel distress as they anticipate their exposure to that material. Similarly, Kimble and colleagues (2023) found that people with a history of more serious sexual assault reported more distress before viewing warned-about negative material concerning a rape than their counterparts without such a history, suggesting that people with a relevant history of trauma may have found the warning especially distressing. In other words, warnings themselves can be distressing—and might even be especially distressing for the very people they are intended to help.

It is true that the increases in distress reported in these studies are relatively small, and it would be reasonable to suppose that the distress from a single warning would dissipate relatively quickly. Indeed, as described in the previous section, once people are exposed to the negative material, those who did and did not receive a warning often report similar levels of distress. But it is plausible that if college students encounter frequent warnings, these small effects might accumulate, creating a tendency to see mildly negative material as more threatening and generating more and longer-lasting distress (Anvari et al., 2023; Jones et al., 2023). Therefore, again, the data suggest providing trigger warnings in college material will not reduce—and may increase—students’ distress.

Conclusion

Taken together, the growing body of work on the effects of trigger warnings—including the work by Kimble and colleagues—fits with the idea that these warnings are not only unhelpful in any of the ways intended, they can be harmful in ways not intended. These studies suggest that people do not use trigger warnings to avoid negative material, nor as a prompt that helps them reduce their subsequent distress. Instead, they find the warnings alone distressing. What is more, the findings to date suggest that people currently experiencing clinically significant symptoms of distress, or who have a history of trauma that overlaps with the content of the warned-about material, receive no unique benefits from trigger warnings, and may instead find them uniquely distressing. Therefore, even if people did use warnings to avoid negative material, it is likely that they would still experience increased distress simply due to the warnings themselves. And even if trigger warnings did (under some yet-to-be-discovered conditions) reduce people’s distress following exposure to negative material, to justify their use, that reduction would have to be large enough to counterbalance the increase in distress caused by seeing a warning in the first place. Future research could attempt to develop instructions that help people to prepare for negative material in such a way that reduces their subsequent distress without increasing their anticipatory distress. But in the absence of such instructions, the evidence suggests that college instructors should forego the use of trigger warnings.