When conducting a scientific study, there's always one rogue variable scientists must watch out for: mischievous teens. In many studies of youth lifestyles and mental health, results have been altered (some dramatically, others negligibly) by teenagers who think it's funny to claim they're part of the LGBTQ community and also that they have outrageous eating or drug-use habits.

A new study in the American Journal of Public Health by NYU economics professor Joseph R. Cimpian explores the effect that these "trolls" have on scientific research. He first decided to look into the issue when a colleague alerted him that, according to their data, the number of blind LGBTQ youth was way above expected. He told The Daily Beast:

"What we found is that 'gay' kids are way more likely to be blind and to be deaf and to have three or more children of their own and all sorts of things. When you look at these data, you think, 'This is ridiculous!'"

He drew the correct conclusion:

"Clearly the kids are messing with us."

Looking at the CDC's 2015 Youth Risk Behavior Survey, Cimpian and his team used a complex, computer-driven method to sort out what they labelled as "mischievous responders." Boiled down to its simplest form, their technique involved identifying and eliminating answers from participants who claimed to be gay, but also claimed to do things like "[eat] carrots four or more times a day every single day."

Though Cimpian knows NYU professors "may not necessarily be the best at figuring out what kids are going to think is funny," they're getting better and better at picking out the trolls:

"We do know that we can get very different responses particularly for high-risk, low-frequency kind of outcomes. Things like excessive drug use and excessive alcohol use."

Weeding out the "mischievous responders" can have a major impact on a scientific study's results. Cimpian claims that removing the trolls from their data had a significant effect on "overall estimates of LGBQ-heterosexual youth disparities, especially among male youths." Other areas that weren't as funny to joke about, however, (such as suicide ideation) were left unchanged by removing the trolls:

"Drug- and alcohol-use disparities were among those most affected by suspect data, whereas disparity estimates for being bullied, feeling sad or hopeless, and thinking about suicide were not noticeably affected by suspect cases."

Cimpian's research reveals that some of the disparities between heterosexual and LGBTQ teens, especially when it comes to drug use and eating habits, may have been dramatically overestimated in previous studies:

"I think that [my study] suggests that the disparities are, particularly among males, not as big as the literature previously would have suggested. And some of those disparities actually diminish to basically nothing. They're definitely not statistically significant in many cases—but, not only that, the actual differences are virtually nothing."

It's worth noting, however, that most of the "mischievous responders" were young boys. Almost no effect was had when researchers tried to remove the "trolls" from the female data set.

One troubling result of Cimpian's study was the revelation that the mental health disparity between LGBTQ youth and heteronormative youth remained the same even after removing the trolls. Put simply, though they may not be eating a huge amount of carrots, it seems LGBTQ youth are truly more likely to suffer from mental health issues by a wide margin.

Though the real root of the problem is the teens who think it's funny to claim they're eight feet tall, gay, and constantly eating carrots, Cimpian admits getting them to stop may be an impossible task. He admits many of his adult colleagues may have even been tempted:

"A lot of times when I even talk to fellow faculty members about this, they say things like, 'Oh, I would have been the kid that you would call a mischievous responder.'"

H/T - The Daily Beast, American Journal of Public Health