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It might seem hard to believe that we live in a day and age where otherwise healthy people willingly ingest laundry detergent or burn their arms on a hot stove. But challenge videos are all the rage, and it haven't for a long time, so it seems like they're here to stay.

Before Tide Pods and hot coils, there was the cinnamon challenge: eat a spoonful of powdered cinnamon, never mind the potentially life-threatening effects on your throat and lungs. Other challenges have involved lighting yourself on fire, rubbing your skin off with erasers, or pouring vodka into your open eyes. Which begs the eternal question: whhhhhhyyyyyyyyyyyy????

As in, why is ANYONE doing any of these things? Some of the obvious factors — like a thirst for stardom, or a fat check from advertisers, or just easy content that's not super hard to make — might be part of it. But psychologists think what it really comes down to is an unfortunate combination of social media and developing brains.

You might think you'd need to have half a brain to even attempt any of these challenges. And you'd be kind of right—at least, in the sense that brain size and shape may be a factor. Most of the people trying this stuff are kids and teenagers, and they're probably doing it for the same reason people in those age groups often make other irrational decisions, like I look back my own past, and I know that I made those decisions as well : your brain is still developing until well into your 20s.

In teenagers and young adults, the brain is still growing, and its architecture is changing as new neural connections are made and others are snipped. And this might result in like me going out my friend's backyard and making a bomb, which was a bad idea. Some areas reach maturity faster than others.

Among the first are frontostriatal reward circuits, which encourage you to seek new, more adult-like experiences. You know — to explore, experiment, and figure out your place in the world separate from your family. At the same time, your brain becomes more sensitive to, well, pretty much everything, but especially neurological rewards.

That's because, in addition to these raging hormones, you start producing more receptors for the neurotransmitter dopamine in your brain. So to teenage you, roller coasters are more thrilling, love is more exciting, and life, quite literally, tastes sweeter. And because of that, teens tend to want more of everything.

Psychologists have found that reward-seeking behaviors are highest in 12-15 year olds, while sensation-seeking peaks in 17-18 year olds. But even though all of this encourages independence to prepare teens for their adult lives, it also makes them prone to impulsive and risky behaviors. And while teenage brains are favoring all this dopamine-fueled risk taking, pruning and reshaping is still happening in the prefrontal cortex.

That's the part of your brain responsible for impulse control and rational thinking. And it doesn't mature until well into your 20s. So from the ages of around 12-24, your brain is pretty much wired to make you take risks, yet your ability to evaluate how risky those things really are is impaired.

Which helps explain why riskier behaviors, from violence to criminal behavior, unprotected sex, reckless driving, and recreational drug use are so much more common in people under the age of 25. Maybe a mouthful of cinnamon isn't that bad, considering. Of course, teens and college-age kids doing stupid things is nothing new.

But social media is, and it makes these dopamine-driven stunts more visible. So if you didn't grow up with social media, part of why it might seem like less of this happened in your day is that everything the young'uns are doing now is just more public. At the same time, in developing brains, the feeling that everyone could be watching hits a nerve — or certain collections of neurons, at least.

In a 2012 study on 40 adolescents, 14 young adults, and 12 regular adults, researchers investigated this using fMRI, a technique that measures brain activity levels based on blood flow. The team found that when the adolescents in particular were told their choices in a simulated driving game were being monitored by a peer, they had greater activation in the ventral striatum and orbitofrontal cortex. Those areas help assess the value of potential rewards, and they tended to be more active when the teens were making risky decisions.

The same effect has shown up in other studies, and it supports the idea that teens anticipate a greater feeling of reward when their peers are around, so they take bigger risks. That makes a lot of sense, because we're a very social species. For our ancestors, rejection could literally be a death sentence.

So our brains perceive any social reinforcement as rewarding, just like the other things we need to survive. Since social media is basically the equivalent of having tons of people watching, that can feel like a lot of potential extra reward … maybe enough to make eating laundry detergent seem worth it. For example, a 2016 study of 32 teenagers found that those early-developing frontostriatal reward circuits activated more when they looked at photos they'd posted that got more likes. like.

Meanwhile, when they looked at pictures of their peers doing risky things like underage drinking, they had less activity in areas of the brain associated with cognitive control. Those are the processes involved in working toward a goal, rather than acting on impulse. So it's more than just a general predisposition to doing risky things while not being all that great at evaluating the consequences.

Having peers around — even if they're just watching on social media — might lead to both a greater feeling of reward and a tendency to be more impulsive. When it comes to viral videos, that could add up to a desire to eat detergent or rub you skin off with an eraser. Sure, it's dangerous, but it can be hard for the developing brain to care very much.

At the same time, likes and views feel like the social approval we're all so desperately seeking. Of course, not every teenager was eating tide pods, by a long stretch. And not every person eating tide pods was a teenager.

Those individual differences are what researchers are digging into now, hoping to figure out the best ways to reduce the dangers young adults pose to themselves. Because social media is not going away, and teens will do dangerous stuff with or without it. So psychologists want to better understand why some people take small risks while others take life-threatening ones.

If there are ways to guide where a young person's behavior lands on that spectrum, maybe we can help people stay away from things like eating detergent or making a bomb in Drew's backyard… if you are watching, hey Drew! That was fun... No!

It's bad! Thanks for watching this episode of SciShow Psych! If you want to better understand why even level-headed adults sometimes do some very not-so-smart things, you can watch our episode on why we take risks. [♪ OUTRO ].