According to Merriam-Webster, a trigger warning is “a statement cautioning that content (as in a text, video, or class) may be disturbing or upsetting.”

Trigger warnings arose out of the psychological concept of Post-Traumatic Stress Disorder (PTSD) “triggers,” events or experiences that can cause a trauma survivor to re-experience a traumatic incident from the past. Throughout 2016, and 2017, trigger warnings – just like safe spaces – have, as U.S. News noted, been a subject of much debate in academic circles, and on college campuses in particular.

In an effort to examine whether trigger warnings are actually effective or not, a team of Harvard researchers conducted a study, titled “Trigger warning: Empirical evidence ahead.”

Authored by Benjamin W. Bellet, Payton J. Jones, and Richard J. McNally the study was published in the peer-reviewed Journal of Behavior Therapy and Experimental Psychiatry.

Two hundred and seventy individuals were recruited for the study and asked to provide feedback on passages from literature. Those with a history of trauma were excluded. Participants were asked to read three types of passages: neutral passages (e.g. a character description from Moby Dick), mildly distressing passages (e.g. a description of a battle from Flags of Our Fathers), markedly distressing passages (e.g. the murder scene from Dostoevsky’s Crime and Punishment).

Some of the participants received a trigger warning before the markedly distressing passages (“Trigger Warning: 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).

The researchers found that participants in the trigger warning group reported greater anxiety in response to reading distressing passages, but only those who had a strong belief that words can cause harm on their own. Trigger warnings made a difference, but not a positive one. Meaning, those who read the trigger warning did not become more desensitized to distressing literature. Some of them were, in fact, more distressed, and anxious.

“Participants in the trigger warning group believed themselves and people in general to be more emotionally vulnerable if they were to experience trauma. Participants receiving warnings reported greater anxiety in response to reading potentially distressing passages, but only if they believed that words can cause harm. Warnings did not affect participants’ implicit self-identification as vulnerable, or subsequent anxiety response to less distressing content.”

Bellet, Jones, and McNally concluded that trigger warnings may actually undermine psychological resilience. What trigger warnings actually do, the researchers concluded, is increase immediate anxiety response for individuals “whose beliefs predispose them to such a response.”

Although important, the study is not without its limitations, researchers added, with the biggest one being the fact that the study was not conducted in a student sample. It, therefore, needs to be replicated in a student sample, since the student population is particularly likely to be exposed to trigger warnings.