A recent meta-review of 12 other studies on the efficacy of “trigger warnings” conducted by Australian experimental psychologist Victoria Brigland confirms what clinical psychologists have long understood: trigger warnings don't work. Instead of reducing the stress students feel upon encountering sensitive subjects, they only make it worse.

This should come as no surprise. Brigland’s study confirms what research on the subject has shown for years. For instance, a recent Harvard study demonstrated that students who receive trigger warnings report greater anxiety than those who don't. Another study even suggested that trigger warnings prolong the distress of negative emotions .

The unintended consequences of trigger warnings are what happens when psychology becomes ideological. Too often in school environments, policies that regulate behavior are not crafted by experts in psychology or informed by the latest research but are pushed by political activists who eschew scientific rigor and reward ideological conformity.

Trigger warnings — or “content warnings” as they are sometimes called to avoid referencing guns — are ostensibly used with the well-being of the individual student in mind. But trigger warnings run counter to best psychological practices for treating trauma. Richard McNally, professor and Director of Clinical Training at Harvard University’s Department of Psychology and author of Remembering Trauma, goes so far as to describe trigger warnings as “countertherapeutic” because they encourage the avoidance of reminders of trauma, and this avoidance “maintains PTSD.”

Instead, the best way to treat PTSD is through exposure therapy, which gradually teaches an individual to approach trauma-related memories, feelings, and situations. Trigger warnings defy the basic precepts of exposure therapy, which the National Institute of Health describes as the gold standard for treating PTSD. Rather than sap the source of trauma of its power through gradual exposure, they serve to reinforce the fear and anxiety felt upon encountering it.

Imagine that an individual has been traumatized by spiders and suffers from debilitating arachnophobia as a result. Now imagine that every time he or she enters an environment that contains spiders — say a garden or a barn — a “warning sign” were to suddenly appear out of thin air. Would this serve to liberate the individual from fear and anxiety? Or would it only serve to reinforce the idea that spiders are inherently anxiety-inducing? The scientific data indicate the latter is true. So does common sense.

It's important to note that many well-intentioned teachers use trigger warnings with the best interests of their students at heart. In a recent article in the Wall Street Journal, Kate Manne, an associate professor at Cornell University, is quoted as saying: “How do we know trigger warnings work? A key clue for educators like me who use them is that some students say they help and thank us for our consideration. And that’s all trigger warnings are in the end: a basic courtesy, a form of human consideration: a kindness.”

However sincerely held these sentiments might be, they are misguided and must be refuted. Indeed, they are demonstrably harmful and defy science. It is not “kindness” to exacerbate the anxiety of students. It is also foolish to rely upon the patient to determine the best cause of treatment. Just because students say something is healthy doesn’t mean that it is.

Now more than ever, students need teachers to tell them hard truths. A good way for teachers to begin would be to lovingly explain the science behind trigger warnings and then by removing them from formal instruction materials.

Undoubtedly, there will be ideologues and political activists who continue to demand trigger warnings in our schools regardless of the damage they cause. For them, trigger warnings serve to enforce an ideology that relies upon expanded definitions of the words “violence” and “trauma” for the implementation of a political program.

But those sincerely concerned about the mental health crisis afflicting our youth, particularly our young girls, should understand that eliminating trigger warnings from schools is a no-brainer. Science says students don’t need to be coddled; they need to be strengthened. We should take heed.

Peter Laffin is a writer in New England. Follow him on Twitter at @ petermlaffin .