Should lecturers warn students before covering distressing topics like sexual assault or racism? Most people think so. In fact, nearly 9 in 10 students in our study said they supported the use of trigger warnings. And between 39% and 51% of university lecturers already use them.
But good intentions don’t always produce good outcomes. A growing body of research suggests that trigger warnings, brief alerts about potentially upsetting content, don’t actually reduce distress. A meta-analysis of all available studies found that warnings increase anticipatory anxiety without reducing negative reactions to the material itself. Other research has found that warnings can even strengthen the belief that trauma is central to one’s identity, a pattern linked to worse PTSD symptoms.
So if trigger warnings don’t help people cope, do they at least make students feel supported? Some scientists have argued that even if warnings fail clinically, they might still function as a way for lecturers to show students that they care. Critics have dismissed this as “virtue signaling.” But until now, nobody had actually tested either claim.
Putting trigger warnings to the test
In our recent study, published in the Journal of Experimental Psychology: Applied, we recruited 738 American university students and asked them to watch short lecture videos about psychological trauma. The study was conducted in collaboration with Payton J. Jones, Victoria M. E. Bridgland (Flinders University), Benjamin W. Bellet (Massachusetts Mental Health Center, Boston), and Richard J. McNally (Harvard University), The videos were identical in content; the only difference was how they began.
Some lecturers opened with a trigger warning. Some gave a safe space notification, reassuring students that the classroom was a space where they could speak freely and prioritise their emotional wellbeing. Some gave both. And some gave neither.
The trigger warning went like this: “Before we begin today’s lecture, I want to issue a trigger warning. The content we’re about to cover includes discussions about interpersonal trauma, such as sexual violence. This content may evoke a distressing emotional reaction for some people, particularly those with a history of trauma.”
And the safe space notification said this: “Before we begin today’s lecture, I want to emphasise to everyone that this classroom is a safe space. If at any point the material becomes too distressing, please feel free to disengage as necessary. It’s essential to prioritise your emotional safety.”
After watching, students scored the lecturers on several dimensions, including how trustworthy they seemed, how much they cared about student well-being, how safe students would feel discussing controversial topics in their classroom, and their best guess at the lecturer’s political leaning.
Trigger warnings fell flat
Trigger warnings had no detectable impact on any of the perceptions we measured. Students who received a trigger warning didn’t rate the lecturer as more trustworthy or caring, nor did they feel more psychologically safe. They weren’t any more willing to discuss difficult topics.
This was true even for students with a history of trauma, including survivors of sexual assault, the very population that trigger warnings are most often designed to protect. We directly asked trauma-exposed participants whether the lecture content reminded them of their own experiences. Nearly half said it did. Yet their perceptions of the lecturer and classroom environment did not change when they received a trigger warning.
Although most students endorsed trigger warnings, they didn’t rate the lecturers who gave them or their classroom environment any more positively. That’s significant because one of the last remaining arguments for trigger warnings is that they make people feel supported. Our data suggest that’s not the case.
— Sam Pratt
Safe spaces changed the room
Safe space notifications told a very different story. When lecturers told students that the classroom was a safe space, students viewed them as more trustworthy, benevolent, and caring. They reported feeling more psychologically safe and more comfortable participating in discussions about controversial issues, including politics, religion, sexual orientation, gender, and trans identity.
But there was a trade-off. Lecturers who gave safe space notifications were also perceived as more politically liberal (in the American sense of the term). Students rated these lecturers as more likely to hold left-wing authoritarian beliefs, including support for top-down censorship, the idea that certain viewpoints should be suppressed for the greater good.
In other words, students appreciated the safe space notifications but simultaneously assumed that the lecturers who issued them were ideologically biased.
Beliefs about language determine reactions to trigger warnings
Perhaps the most surprising finding was that students’ political ideology, liberal, moderate, or conservative, made no difference. Liberal and conservative students reacted to trigger warnings and safe spaces in essentially the same way.
The real difference maker was students’ beliefs about whether words can cause lasting psychological harm, and their support for top-down censorship. Students who scored low on these measures, who believed language is generally harmless and free expression should be protected, reacted more negatively. They perceived lecturers who gave trigger warnings as more authoritarian and felt more reluctant to speak up. Students who scored high on these measures, by contrast, tended to see lecturers who offered safe spaces as more trustworthy.
This suggests that the trigger warning debate isn’t really a left-versus-right issue, even though it’s often framed that way. It’s a debate over the power of language itself and whether certain forms of speech are inherently harmful and require regulation.
What should educators do?
When it comes to trigger warnings, the evidence is now fairly clear. They don’t reduce distress, they don’t help trauma survivors, they don’t help people opt out of distressing content, and as our study shows, they don’t even make students feel more supported. Trigger warnings may feel like the compassionate choice, but across every outcome we measured, they had no detectable benefit.
Safe space notifications are a more complicated story. Our findings suggest they have real benefits: they build trust, foster psychological safety, and encourage open discussion. But they also come with ideological baggage, potentially undermining the perception of political neutrality that many lecturers strive for.
One solution is to reframe the message. The term “safe space” has become a political flashpoint, and phrases like “emotional safety” carry their own connotations. Lecturers might instead say something like: “Before we begin, I want to remind you that this classroom is a place for open and civil discussion. Your education is incredibly important to me, but so is your mental health and wellbeing. Let’s commit to supporting one another by showing respect and kindness, even though we may have very different life experiences or perspectives.”
This kind of language might preserve the positive effects without signaling partisanship, though this remains an open question for future research.
What’s clear is that grounding classroom practices in evidence, rather than intuition, leads to better outcomes. Trigger warnings may feel like the right thing to do. But feeling right and being effective are not the same thing. Sometimes, the most supportive thing a lecturer can do is skip the warning and focus on building a classroom where students actually want to speak up.
Reference
Pratt, S., Jones, P. J., Bridgland, V. M. E., Bellet, B. W. & McNally, R. J. (2025). Sending Signals: Trigger Warnings and Safe Space Notifications. Journal of Experimental Psychology: Applied. https://doi.org/10.1037/xap0000541
