If you spend time on social media, it is very likely you have come across trigger warnings. On websites like Twitter and Tumblr, some people use terms like "tw: rape" or "tw: self-harm" before discussing such subjects. 

The purpose here is to give the reader a heads-up so they can emotionally prepare for the subject or avoid reading the content altogether. In other words, these warnings are meant to protect vulnerable individuals from something that could "trigger" a traumatic flashback and lead to distress.

But how effective are they as a measure? It is an interesting question, especially given the fierce debates it has prompted in academia — particularly in college campuses such as the University of California, Berkeley or the London School of Economics.

Some professors provide trigger warnings before lectures, at times even giving students the option to avoid a triggering class. The argument here is that it prevents blindsiding as a way to engage better in class, while still supporting students' mental health.

But others have been more critical, suggesting these warnings threaten academic freedom. The concern here is that warnings are counter-productive, allowing students to hide inside a bubble instead of challenging their own ideas.

In a recent series of studies, researchers from the University of Michigan decided to study how these warnings influenced responses.

"Surveys show that trigger warnings and other similar warnings are increasingly common, but there is virtually no research as to whether they actually make people feel better or whether they lead to avoidance," said lead author Izzy Gainsburg, a doctoral student in psychology.

The first study featured 80 participants, asking them to report their emotional and behavioral responses when given a warning before being exposed to the associated content. Participants actually expected to feel more anxious when given a trigger warning. Furthermore, those who believed that trigger warnings were "protective" were also more likely to avoid the content. 

Next, 275 participants in the second study were given the choice of watching one of two fictional videos based on their titles. Once again, participants expected to feel more stress before watching videos with trigger warnings compared to those without. In the third and final study involving nearly 1,000 people, trigger warnings preceding essays increased anticipated distress and attentional-regulation strategies, but "reduced experiences of negative affect."

The most important and "ironic" observation was found among participants who believed that trigger warnings were protective. Those who were given warnings in this group felt no better than those who were not given any warnings.

But Gainsburg noted that the debate is far from over, as these findings only scrape the surface of how trigger warnings affect emotional experiences. "There is so much more that can and needs to be done, especially if institutions are encouraging or mandating their use," she said.