Trigger warnings said to harm college students, but evidence is thin

July 30, 2018 • 9:00 am

“Trigger warnings” are of course cautionary statements given out, usually by college professors, before they present disturbing material to students. The intent is to prevent those who might have been traumatized by that subject or a related one (usually people with PTSD: post-traumatic stress disorder) from being re-traumatized.

My view of such warnings is that material that might be disturbing to everyone should be preceded by a caution (e.g., an ISIS beheading video, other gory stuff or crimes like rape), and that the professor should announce to the class at the beginning of the semester that if anyone has trigger issues, they should come to see the professor and get a list of course material that they might find offensive. But I also think that students should still be responsible for mastering “triggering” material presented in class, that students with trigger issues should be seeing a therapist, and that, in the long run, trigger warnings aren’t helpful in curing the individual of their phobias (psychologists think that one must be exposed to material to get over being triggered by it).

Further, trigger warnings might serve to keep the traumatized student in a status of perpetual victimhood. Finally, the list of stuff that has been deemed potentially triggering is so long that it’s impossible to give warnings in advance about every possible cause of anxiety. Here, for instance, is a list from a sympathetic intersectional website:

One simply can’t warn people about all that stuff in advance!

A new paper, which has been given publicity by lots of right-wing websites, piqued my interest, as it purported to show, according to those sites, that trigger warnings don’t work. Unfortunately, it shows nothing of the sort—only that trigger warnings can temporarily increase one’s sense of vulnerability in non-traumatized people exposed to disturbing prose.

Here’s the paper (click on screenshot to get to article, free pdf is here, and the reference is below). The paper is by Benjamin Bellett, Payton Jones, and Richard McNally, all at Harvard University’s Department of Psychology, and it’s in a reputable journal: Behavior Therapy and Experimental Psychiatry.

The title is cute, but what did the researchers do? They exposed 270 people recruited on the internet to prose passages considered either neutral, mildly distressing, or markedly distressing. These weren’t mostly college students, as the median age of subjects was 37 (see paper for other characteristics). Here’s what the authors say about the passages:

To simulate an academic setting, we chose passages from world literature that commonly appear in high school or college courses. Each passage was standardized in word length, and passage exposures were set to a minimum of 20 s before participants were allowed to continue to the next screen. Transparent attention checks based on the passages’ content assessed whether participants were attentively reading the passages (see supplementary materials S2 for an example of a content check question). We used three types of passages. Neutral passages were devoid of disturbing content (e.g. a character description from Herman Melville’s Moby-Dick). Mildly distressing passages concerned themes of violence, injury, or death, but lacked graphic details (e.g. a description of a battle from James Bradley’s Flags of Our Fathers). Markedly distressing passages contained graphic descriptions of violence, injury, or death (e.g. the murder scene from Fyodor Dostoevsky’s Crime and Punishment). See supplementary materials (S1) for a sample passage from each category.

Subjects with PTSD or who said they had trauma issues were excluded from the study. The authors also surveyed the subjects’ demographics (sex, race, ethnicity, political stance etc.) and attitudes, like whether they believed in advance that words could cause harm and whether they thought trigger warnings should be used (80% said yes in advance). Participants were also asked if they had any history of psychiatric disorders.

They then exposed the subjects to three mildly distressing passages to get a baseline anxiety level. After that, they read ten passages in random order: five were markedly distressing and five were neutral. Half the subjects were given a trigger warning before reading the distressing passages (“The passage you are about to read contains disturbing content and may trigger an anxiety response, especially in those who have a history of trauma”) and half were not. The subjects were then assessed for various psychological variables, and multiple regression analyses were use to tease out the effects of single factors.

Here are the most important results:

  • Students who got trigger warnings saw themselves as “more vulnerable to suffering persistent negative emotional effects in the event of experiencing trauma”. That is, they say themselves as having become more easily traumatized. But this effect was small: the increase in level of vulnerability was only 5.2% and the probability that this was true under the null hypothesis of no effect was less than 0.05 but not much lower. That’s not considered a very significant effect, nor is it a large one.


  • More students who got trigger warnings believed afterwards that “trauma survivors would suffer persistent emotional effects” than did the controls who didn’t get warnings. But again this effect was small (5.4% increase in strength of that belief), and p<0.05, again not a hugely significant result. They also didn’t correct statistically for multiple comparisons, which would probably make these effects nonsignificant.

These two results are the basis of media reports that trigger warnings were harmful, but of course you can see the problems: not college students, self-report, small and likely nonsignificant effects. Hardly the stuff of headlines. Here are a couple other results:

  • Participants who believed in advance that words can cause harm had a significantly higher increase in anxiety from receiving trigger warnings than the un-warned controls. Again the effect is barely significant (p , 0.05), although the result makes sense.


  • Factors that made people who got trigger warnings even more likely to see themselves as more vulnerable included being a woman, a member of a racial minority, a liberal, a younger person, and, especially strongly, one with a psychiatric diagnosis that did not include PTSD. These all conform to our expectations or to previous results; the psychiatric diagnosis effect was especially significant (p < 0.001, but not significant for the second test of assessing the vulnerability of other people).

This study, I think, says very little about whether trigger warnings work, for those warnings are used to prevent people with PTSD or diagnosed trauma from being re-traumatized without warning. Those kind of subjects weren’t used in this study. Further, the effects were small, so they don’t even convince me that “trigger warnings don’t work and can even be harmful”. To be fair, the authors list a number of problems with the study at the end of their paper, including the fact that they used reading passages and not visual images or representations. All they can really conclude is that “Trigger warnings do not appear to be conducive to resilience as measured by any of our metrics. . . and may present nuanced threats to selective domains of psychological resilience.”

So this is a start, but what we really want to know is whether trigger warnings are helpful to traumatized individuals, and whether they can contribute to de-traumatizing them over the long run. There’s simply not much data on this issue, though the authors mention a poster—not a published paper—by Bruce (reference below) suggesting that physiological markers of anxiety in traumatized individuals were heightened after presentation of a trigger warning compared to “no warning” controls. That, too, suggests that trigger warnings might not be helpful.

So caveat lector.  While the headlines may be comforting to those who don’t like trigger warnings, the data in the paper don’t show that these warnings don’t work—at least when they’re used on traumatized individuals, as is their purpose. And headlines like the one below, from the right-wing website The College Fix, are simply misleading (click on screenshot to read the piece):


Bellet, B. W., P. J. Jones, and R. J. McNally. 2018. Trigger warning: Empirical evidence ahead. Journal of Behavior Therapy and Experimental Psychiatry, in press.


Poster said to show negative effects of trigger warnings on traumatized individuals:

M.J. Bruce.  2017. Predictors of trigger warning use: Avoidance or asserting accommodation needs? Poster presented at the annual meeting of the international society of traumatic stress studies, Chicago, IL (2017, November)


45 thoughts on “Trigger warnings said to harm college students, but evidence is thin

  1. Further, trigger warnings might serve to keep the traumatized student in a status of perpetual victimhood.

    Isn’t that the desired outcome? Demands for trigger warnings seem to be demands that you acknowledge someone’s status as a victim, and thus grant them the high status and privileges owed to such people.

    1. That’s true for some trigger warning advocates. Still, I am glad when when someone says, before a vid is played; “this video contains graphic violence”. It’s courteous.

  2. Oh just great, most of that list if applicable to my BIOS 3640 Forensic Biology for our criminology students (required) and many premeds also take my upper level course at Ohio University (Athens). If the topics trigger these students then they have chosen the wrong career path.

    1. Yes, biology majors and med students better beware! Disclaimer: I did field biology as an undergraduate and early graduate student, so snakes, spiders and insects are fine. And I taught gross human anatomy in medical school for six years, so I can’t think of any items on that list that would really bother me.

  3. “Anything that might intrusive thoughts in people with OCD”?

    Well, that pretty much covers all conversation, no?

  4. Trigger warning: There may be something in here that may offend you.

    That should cover all eventualities, and if they want to know what it is they have to read more.

  5. Lucky I did not ask for any trigger warnings when in the military — probably would have been shot.

  6. … (psychologists think that one must be exposed to material to get over being triggered by it) …

    Been a while since I took a look at this topic, but I believe the indicated treatment involves a sort of “shaping” by which the triggering stimulus is gradually introduced into the patient’s environment. (IOW, ain’t like you up and toss firecrackers at a vet suffering from what used to be called “shell shock.”)

    Were I a professor teaching graphic or controversial material, I’d be inclined to give the warning Jerry proposes, but I’d be chary to give a student a pass on responsibility for any material absent documentation that the student was currently under treatment for PTSD and that his or her therapist felt the material was “contraindicated” (as they say in med-speak).

    1. Agreed. We’ve been giving what amount to trigger warnings for violent and graphic images for a long time, but if a student wants to skip that material because it simply makes them uncomfortable, they wouldn’t have permission from me to do so. Unless you are diagnosed with PTSD and your PTSD relates to that particular subject, you have to deal with being a bit uncomfortable or anxious, just like people do every day. Additionally, I would not provide warnings for anything beyond the most graphic and upsetting imagery, like when I assigned Ellis’ American Psycho, or Noé’s Irreversible. I don’t know what class I would be teaching that involved both of those works, but, whatever that class would be, I can’t imagine anyone of weak constitution signing up for it!

      1. Ellis’s American Psycho — you mean, in case a student had had a traumatic experience with excessive product? 🙂

        (As to Irreversible, I recall reading an interview with the lovely and talented Ms. Monica Bellucci where she said she could never wear that dress again.)

        1. It’s amazing that Mary Harron never made another good movie. It makes no damn sense. AP is brilliant.

          It’s been a long time since I read the book, but I remember that morning routine scene going on for at least a few pages, and maybe significantly more than a few.

          1. And speakin’ of American Psycho the movie, it was a much, much better adaptation of BEE’s fiction than was Less Than Zero — which was terribly miscast, except for the brilliant performances by James Spader and Robert Downey, Jr.

            1. Yup, Less Than Zero could have been a great movie, especially with those two. RDJ is fantastic and Spader always plays that slick, low-key menace so well.

              1. Yeah, except Spader originally had me fooled when he first arrived, in Sex, Lies, and Videotape, where he played just the opposite — the sincere, ingenuous shlub. Kinda played that role, too, in White Palace, opposite Susan Sarandon’s older seductress.

              2. “first arrived”?!? Before Sex, Lies, and Videotape, Spader appeared in Pretty in Pink, Less Than Zero, and the film Werner Herzog called “The apotheosis of cinema; the only film to ever touch the universal truth of human experience, in all its chaos and trauma”: Mannequin.

              3. “Arrived” in the sense of getting co-equal top billing. The flick in which Spader (literally) made the transition from nebbish to “slick, low-key menace” was Bad Influence. That and LTZ and Two Days in the Valley really established his persona for me.

                I’d forgotten he was in Mannequin. (Did Herzog really say that?) 🙂

              4. Unless there has been a remarkable coincidence, Herzog definitely did not say that (although one wouldn’t put it past him, the cheeky bastard. He has developed a wonderful sense of humor to accompany his cynicism over the years). Bad Influence is a lot of fun, and Spader actually starts out as the nebbish in that one, so his character actually embodies that career transition. Two Days in the Valley is one of those Pulp Fiction rip-offs, but certainly among the better ones and quite enjoyable. I think the best of what I’d call Pulp Fiction-adjacent (because it’s not a rip-off) is The Way of the Gun. Ever seen that one? It’s great!

              5. Saw Way of the Gun and enjoyed it. For some reason — and it’s been a while since I’ve seen either so don’t really remember why — I tend to think of it in tandem with another cult flick from that era, The Boondock Saints.

                Two Days in the Valley was definitely Tarantino-derivative, but a lot of fun. Great cast, including some of my favorite character actors.

              6. Way of the Gun is leaps and bounds ahead of The Boondock Saints. The latter is overly dramatic, has pretty terrible dialogue, and has only two really good performances (Willem Dafoe and Billy Connolly). The former is excellent in nearly every way, beyond the cheap-looking cinematography. WotG has wonderfully witty dialogue and offbeat humor, an excellent plot, and very good to great performances all around (except maybe, as usual, Juliette Lewis. It’s one of the few films where I find Lewis tolerable, though).

              7. Also, Boondock is trying far too hard to be “cool.” Some scenes make me cringe with embarrassment, but it’s definitely still a fun watch if I’m in the right mood. I just hate to see WotG or TDitV get lumped in with it.

              8. Oh, and sorry for yet another post, but if you’ve never seen the documentary Overnight, get a hold of it. It’s a documentary that follows Troy Duffy as he gets manages to sell and then make Boondock, and it’s fascinating to watch him go from a working class Boston man to the pinnacle of arrogance, destroying his possibly excellent chance of becoming an established filmmaker in the process. By the end, nobody will ever work with him again, including all the friends/band-mates he alienated in the process. I really can’t do it justice with this description.

  7. Trigger warnings are weak and silly in most cases, but the list omits what would be mine if I succumbed to them: animal abuse or torture.

    1. Excitaphobia; commonly a result of exitphobia (fear of leaving college).

      Trigger warning: no reference ahead.

  8. … trigger warnings can temporarily increase one’s sense of vulnerability in non-traumatized people exposed to disturbing prose.

    Hardly surprising. Sounds like a cognitive bias related to the well-documented halo/horn effect.

  9. I think you’re being overly generous in saying that the purpose of trigger warnings is to prevent students with PTSD and other disorders from encountering things which would trigger them. That’s simply not how trigger warnings have been applied in my experience (obviously others will have other experiences). Mostly they’ve been used to label material deemed “offensive” by some pressure group, and as an excuse to shut down discussions. This violates the foundational principle upon which the university system was built.

    There’s a difference between the primary purpose of a thing, and the way you sell the thing. I think trigger warnings were sold to us as a way to protect the most psychologically vulnerable–but their purpose is to provide a handy way to shut down discussions that powerful groups don’t like.

    More worrying: Even if we assume the best of intentions here, trigger warnings can be easily abused to silence ideas that are deemed “offensive”.

  10. (psychologists think that one must be exposed to material to get over being triggered by it).

    Psychologist here. Right on.

    There are always two messages in any communication. There is the “overt” message, or what is being stated, and then there is the “behavioral” message, which is communicated by one’s posture in the interaction.

    An example of this is why it’s not a good idea to directly give advice. Regardless of the specifics of the advice, telling people what to do implies that they’re too stupid to figure it out for themselves, or else too unethical to do the right thing.

    Leading questions, or reflective responses, on the other hand, imply that you think they’re smart enough to figure it out for themselves.

    Trigger warnings imply that you think they’re weak.

    It’s fine to give a general warning to a class, but nobody should be able to avoid the material altogether. If they can’t handle the content of a class, they shouldn’t be in that class.


  11. Whoever made that list needs to get out more; that’s a pretty narrow list of -isms. What about Communism? Mercantilism? Modernism? Seriously, though, reading that list one has to wonder whether there is any useful course of study that wouldn’t touch on many of those? Certainly, the Humantities and Social Sciences are out.

    1. All medical and biological fields are out. The ROTC is out (swearing is #1–on a college campus!!). Literature is out (sexuality is a common topic). Art and art history are out (sex, violence, weapons).

      I suppose physics, chemistry, and astronomy would be okay, as long as you never touched on their history and avoided any discussion of their implications for Creationism….

      The trans one and dismissal of (insert list here) would be very easy to turn into “….and anything else we don’t like”. A computer science course doesn’t address those issues; it is, therefore, dismissing them? Computers are expensive–that’s dismissal of the experience of poor people!

    2. We mustn’t forget Cubism and Embolism! Of course, all literature (sex! death! shaming! slurs!), with the possible exception of Winnie the Pooh, would have to have triggers.

      As others have pointed out, the whole trigger warnings fad is intrinsic to the larger fad of victimhood culture. The serious question is therefore: where did THAT come from? Jon Haidt suggests it is an outcome of helicopter parenting. I suspect something deeper must be involved, but I can’t think of what.

      1. Winnie the Pooh deals with addiction (his love of honey), exclusions (Rabbit vs. just about everyone), ecological exploitation, imperialism…..

        “The serious question is therefore: where did THAT come from?”

        It seems like an outgrowth of the Civil Rights Movement. I don’t mean it’s an intentional or even necessary one–I’m talking an outgrowth akin to a tumor. People realized that they could convert the movement to end racism/sexism/whatever to a way to maintain their own personal power. Oppressed people band together; it’s human nature. This allows you to fairly easily build a voting block that feels morally obliged to keep you in power. So the power-hungry find ways to keep everyone feeling oppressed. Eventually it becomes obvious that “oppression” is now the coin of the realm, and everyone wants in on what has become little more than a scam.

        After a while, it became clear that saying you were oppressed and offended became a good way to control the conversation. This lead to trigger warnings. You could claim oppressed status, say something triggered you, and suddenly it’s not allowed to be discussed. YOU get to set the terms of the conversation; YOU get to determine the content of debates, classes, etc. It doesn’t take a Harkonen to figure out how to spin that to political advantage!

        1. “Winnie the Pooh deals with addiction (his love of honey), exclusions (Rabbit vs. just about everyone), ecological exploitation, imperialism…..”

          Don’t forget Eeyore’s depression! Trigger warning: mental health issues.

  12. Interesting, I did not know that people studied this.

    Unfortunately I have nothing to add after this exemplary analysis. Except noting that the paper title triggered me: there was empiricism, but very little definitive “evidence”.

  13. Trigger Warning: Questioning Trigger Warnings
    (–apologies to Kurt Godel)

    The presence of very prevalent triggers such as spiders along with fairly rare ones such as “talk of drug use (legal, illegal, or psychiatric)” is extremely problematic.

    Obviously, any victim of child abuse or one with a close family member having committed suicide is more likely to be triggered. This should be evident without a study.

    I for many years was triggered by needles but I recognized it as my own eccentric problem and didn’t expect society to warn me about it. (I got over it when an illness in 2002 made it necessary to have my blood drawn twice a month for a year.) When seeing the re-edited cut of “The Exorcist” in 2000, my friends noted I was far more discombobulated by Regan’s medical exam involving almost a dozen needles than by anything else in the picture.

    I can’t get triggered by Nazi paraphernalia due to having seen both Mel Brooks’ “The Producers” and Charlie Chaplin’s “The Great Dictator” wayyy too many times.

  14. Don’t confuse content warnings with “trigger” warnings. The former informs a normal person that there is content to come which normal, mentally healthy people are likely to find disturbing, or at least shocking if not expected.

    A “trigger” warning is pure horse puckey. Anyone with genuine trauma issues should be exposed to “triggers”, to become better at coping. If such a person can’t handle normal exposure in public, they should be institutionalized and given therapy until they can.

    There’s no question in my mind that “trigger” warnings are harmful, both to those who have legitimate traumatic experiences they are trying to overcome, and those who are simply being isolated from reality.

    1. You seem to be referring to exposure therapy here.

      I’ve done exposure therapy and there are no surprises. You’re told what is going to happen, how it’s going to work, and then a therapist is there with you, helping you cope with the experience. Similarly, in CBT, if your fear is public speaking, you don’t start by going up on stage in front of an audience. You work through small, intermediate steps.

      Leaving out trigger warnings (for things that reasonably trigger people) is like trying exposure therapy by surprise. Wouldn’t that just add to the trauma?

      At their best, trigger warnings are minimally disruptive courtesies that enable managed engagement with a potentially difficult topic. And in almost all cases I’ve encountered in academia (i.e. not inside the fevered imaginations of TW opponents) they’re used minimally and responsibly.

  15. Clowns…how did clowns not make the list?
    I fail to see how phobias (snakes, spiders, etc.) are akin to triggers related to PTSD.

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