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You can learn a lot about psychology on the internet— and I'm not talking about the dubious websites that let you diagnose yourself by listing off a bunch of symptoms. Those can be really misleading, and if you're worried about your health, you're much better off talking to a doctor.

No, I'm talking about how the internet is an amazing and bizarre place to understand how humans work. Just log into Reddit or Twitter, and you'll see people doing a bunch of really strange things. And psychologists have spent years trying to figure out why.

Like, why is it impossible to win an argument on the internet no matter how right you clearly are? I've got an explanation. Let's be honest—we all try to win arguments on the internet, even though we know it's pointless.

Sometimes when you're scrolling through your Facebook or Twitter feed, bad opinions and misunderstandings just jump out at you, and you have to set your friends and followers straight. But if it seems like your impeccable logic is always met with hostility and digging in—well, that's exactly what's happening. Psychologists have put a lot of thought into how people argue—both online and off—and they've found plenty of reasons why people rarely change their minds.

Part of the problem is that correcting someone can actually strengthen the memory and influence of their original belief—the one you think is clearly wrong. It's known as the backfire effect. A study in the Journal of Consumer Research in 2005 demonstrated this by giving 335 people a list of science facts and myths, then clarifying right afterward which were true and which weren't. 30 minutes later, they asked half of the subjects which things on the list were true, and they were pretty good at separating myth from fact.

But when they tested everyone else 3 days later, that group made a lot of mistakes. Specifically, they recalled a lot of the "false" statements as "true"—but not the other way around. Psychologists think that's because we use how familiar something is as a guide to whether it's true.

And all you need to do to make something familiar is to repeat it. This effect doesn't seem to always happen when people's false beliefs are corrected. Some studies have failed to find a backfire effect, especially when the topic was political.

But pointing out exactly how wrong your Facebook friend is often involves repeating their false beliefs. And when you do that, it's possible that the backfire effect just makes them more sure they're right. Another challenge is that we all suffer from confirmation bias: we can look at the same evidence but come to different conclusions based on what we believe is true.

If evidence confirms what you already believe, it jumps out at you and you pay attention to it. Meanwhile, we tend to gloss over contradictory evidence and just forget about it. A 2013 study with more than a thousand participants showed this with political beliefs.

People were shown the results of a fictional study about gun violence, and were asked whether the evidence supported gun control. But since the study was made up, the researchers made two versions: one in which the data were in support of control measures, and another where the data were flipped. When people were then asked whether the study they read supported gun control, the data barely made a difference.

If the person supported gun control, they thought the data did, too, and vice versa. Ironically, the researchers found that being better at math made this effect worse. You'd think people with better math skills would be more likely to interpret the data objectively, but instead, they tended to recalculate the information in their heads in a way that justified their existing belief.

So even if you've got some super-solid evidence in support of your position, showing it to those who disagree might actually lead them to the opposite conclusion. But if, despite all of this, you still find yourself thinking that you just have to try to change someone's mind because dang it, they are wrong on the internet, there is some good news:. There's also research on what might work.

One group of researchers analyzed a whopping 12,000 arguments on a subreddit forum called "ChangeMyView" to see what the arguments that successfully changed people's minds had in common. They found the most effective tactic was to pick wording that was unlike that of the other side, maybe because unfamiliar wording was a sign that the arguments were new information. Like, if someone's arguing that Kirk was the best Starfleet captain because he led with his gut instinct, pointing out all the times Kirk's instincts have put the crew in danger might not be that effective.

Instead, you might have more success arguing that Picard always opted for the peaceful solution. That kind of shift in language is more likely to change the person's mind, whereas using really similar wording—especially quoting them directly—is seen as nit-picking. The researchers also found that when the original poster used the word "we" instead of "I" to describe their position, the arguments were less likely to change their minds— probably because they were more entrenched in their viewpoint.

And if the debate went back and forth more than 4 times, it wasn't likely to go anywhere. So if you're still arguing on that thread from weeks ago, you might just wanna walk away. Even with the more successful tactics, though, very few people were convinced to change their minds.

And a lot of people are going to this forum because they say they're open to change! So no matter how strong your arguments are, it's probably worth picking your battles. Don't get too discouraged when you can't change the other person's mind—we're just wired that way.

Well, now that we know that internet arguments are basically a waste of time, we can focus on more productive lines of thought. Like what Facebook knows about us. We share our opinions, favorite music, and personal stories all the time—but how much of that does the website remember?

If Mark Zuckerberg stole my grandma's favorite sausage casserole recipe, she's going to be so angry! Here's a video with Hank to hopefully ease your grandma's mind. If you have a Facebook account, you've probably started wondering how much does Mark Zuckerberg really know about you… and the rest of the site's 2 billion users.

One company in particular, Cambridge Analytica, was recently in the news because they took data from millions of Facebook profiles and used them in political campaigns, with questionable or no consent from the users. But what does knowing which memes you like tell companies about you? And does it make you an easy target for marketing and manipulation?

Turns out, you can potentially glean a lot about personality from Facebook data. But while these data can help companies fine-tune some ads, we're not sure if it's enough power to do something like manipulate your voting behavior. Let's start back in 2013, when researchers at the University of Cambridge Psychometrics Centre got permission from over 50,000 Facebook users to see what they clicked “like” on.

These users also took a long survey on things like their Big Five personality traits, intelligence tests, life satisfaction, political and religious views, and even whether their parents had been divorced or whether they used various drugs. Then the researchers designed an algorithm that basically determined which Facebook likes were correlated to the private information from the surveys. Overall, there were over 9 million possible likes, which meant the computer found some surprising relationships.

Like, you might guess that someone with a high score on an intelligence test might like "science" on Facebook. But "curly fries" and "Morgan Freeman's voice" were also closely associated. And it's not a huge stretch that the people who scored most extroverted clicked on "dancing" or "socializing.” But they were also fans of Michael Jordan and Chris Tucker.

The researchers then tried to flip the algorithm: how well could their computer program guess your private information, only knowing your likes? Turns out, it did the best at guessing a person's gender and race, with over 90% accuracy in each. But the accuracy varied depending on different categories.

One of the hardest things to guess was whether a person's parents had divorced before they were 21, which was only 60% accurate—just a little better than tossing a coin. But with just a percentage, it's hard to tell what accuracy is actually any good. Like, could this algorithm know you as well as a close friend, or your family?

So some of the same researchers designed a follow-up study to look at that in 2015. They ran the whole process again, but this time they got a few thousand people and their friends. The participants gave their Facebook data and took a personality test.

And on top of that, a good friend or two took a short test, describing the participant's personality. And pretty much across the board, the like-based computer algorithm did about as well as the users' friends did. In a few cases, the computer did even better—like predicting self-reported alcohol and drug use.

But in the category of life satisfaction, the human judges had the upper hand. It's worth noting that even the algorithm's more accurate predictions weren't perfect. Because these are just correlations, these studies could only test for so much, and every human, as you may have noticed, is complicated.

And not everyone shares the same amount with Facebook. The algorithm was only good if it had enough “likes” for each participant. The researchers compared their data to past research on how good people are at judging each other's personalities.

And they estimated that the computer needed 10 likes to match how well a coworker knows you, 70 to match a friend, and 300 to match a spouse. With over 2 billion active users and a whole lot of likes, Facebook probably has the most data to play with—far more than most other social media sites. But this kind of psychological profile research has been done with other sites too, like blogs or Twitter.

For example, in 2011, researchers gathered 2000 tweets and gave a personality test to a small sample of 279 people. And they found some correlations, like extroversion with people who used more words in their tweets, used more question marks, and used more social identifiers like "daughter," "husband," or "friend.” So who's to say what we might find with a bigger study? Now, for decades before the internet, companies have been targeting ads in TV and magazines based on age, gender, and other demographics.

But adding traits like agreeableness or extroversion to the list and being able to fine-tune arguments to specific people affects the psychology of persuasion. Armed with their computer algorithms that could sleuth out your personality traits from Facebook likes, some of the same researchers did a study in 2017 and tried to see if they could make ads more persuasive. They picked two of the Big Five personality traits that the algorithm identified best: extraversion and openness to experience.

And then they made ads for things like makeup and gaming apps. For extroversion, for example, they made two kinds of ads for makeup. One kind said things like "dance like no one's watching (but they totally are)" to target those who scored high on extroversion.

And another kind said things like "beauty doesn't have to shout" to target those who scored low on the trait. Then, they ran the makeup ads for a week to over 3 million people that were currently active on Facebook, along with ads for a free personality test. With a combination of the data available in public profiles that could be run through the algorithm, and results from the personality test if people filled it out, they could get a sense of the introversion or extroversion of users.

And they found that users were more likely to click the ad that was targeted towards their personality trait, and even more likely to buy the thing. So getting people to buy stuff is a big part of social media. But it isn't the only way data can be used to manipulate people.

Another way is by deliberately changing your emotional reaction to a site. For example, researchers worked with data scientists at Facebook and published a paper in 2014 reporting on manipulations of the content in nearly 700,000 people's news feeds. They took users' posts and sorted them by positive and negative content—lots of happy, celebratory words versus lots of sad or angry words.

And then, they randomly selected users to get more or less of each of those in their feeds. As you might guess, people who got positive content got a little happier, and people who got negative content got a little more negative. At least, as far as researchers could tell from the emotional content of what the people posted next.

It's also worth noting that the participants didn't give express permission to be a part of this experiment. This research technically fell under Facebook's data use policy, so that's what they considered informed consent, but random users didn't know that the website was trying to make them feel good or bad. You know, for science.

Now, there do seem to be limits on manipulation, as far as we know. Cambridge Analytica seems to have developed personality-sleuthing algorithms like the ones used in this kind of research, and advertised that they could swing elections with that data. But none of these studies have shown that companies could use Facebook data to really manipulate thoughts and feelings—like causing people to vote for candidates they weren't planning on.

That being said, it's still a good idea to keep in mind how much you're revealing online, and how companies might use that information in the future. To change your behavior ... which is what advertising is supposed to do. But it's a little ... creepy.

So if nothing else, Facebook definitely has a list of all those cat memes I've clicked ‘like' on. You're welcome, Mark. Yesterday it was dabbing and fidget spinners, and today I found out they did surgery on a grape.

Who knows what tomorrow will bring? Here's more about what can make a meme go viral. At some point, we've all wondered why something as annoying as “Friday” or as delightful as Grumpy Cat can arrive so suddenly and overwhelmingly in our Internet lives.

The Dress was everywhere for three days in 2015, before everybody got over it. And who knows what picture or joke or video will dominate your news feed next? So why do things go viral?

To be honest, this isn't something a lot of people have studied. Really, the only thing newer than the Internet is taking the Internet seriously enough to publish a peer-reviewed study about it. But, when it comes down to it, sharing on the Internet is a lot like other kinds of social sharing.

Gossip and urban legends spread like wildfire, too. Both of these types of sharing have been shown to be driven by emotion. And if you think emotion isn't everywhere on the Internet, then this might be your first time on the Internet....

Welcome! It was this line of thinking that led a group of researchers to look at almost 7,000 New York Times articles from three months in 2008. They were trying to figure out what kinds of things got an article shared enough to make the Times' most-emailed list.

And emotion was the culprit, measured by both computer algorithms with databases of words and humans. Although the Internet can seem like a cesspool of negativity, the scientists actually found that articles that were emotionally positive were more likely to be shared than those that were emotionally negative. But an article that was very negative was more likely to be shared than one that was only mildly positive.

So it wasn't just whether the emotion was positive or negative that mattered. It was also how arousing that emotion was: if you got your lungs pumping and your heart racing a little bit. The same lead researcher did another study, too, where they specifically looked at arousal.

They had 93 students watch videos that provoked either contentment, amusement, sadness, or anxiety. Amusement and anxiety are both considered high-arousal emotions, while contentment and sadness are considered low-arousal. They found that watching one of the high-arousal videos made the viewer more likely to share a neutral article or video that they saw afterwards.

And in second experiment with 40 participants, the researchers found that even just making people run in place for a minute to increase arousal was enough to increase sharing. Which...what!? Wow.

This might be partially why over-the-top “clickbait” headlines work so well—they're trying to shock you or make you laugh. But there's more to social sharing than just arousal. The same researchers pointed to other factors that seem to make something shareable, including how interesting, useful, and surprising it is.

Like, y'know, ibexes licking salt off the side of a nearly-vertical cliff because they crave that mineral. And sometimes what goes viral has little to do with the content at all. Sometimes, it's all about us.

In the 1990s, a team of researchers proposed a new idea for why people go along with trends and fads. They called this concept an informational cascade, which is what happens when one person makes a decision and then others, rather than gathering information to make their own decision, base their decision on the first person's. It might seem like a silly thing to do, but if you think that someone else's decision is based on factors that would guide your own, it can be easy to just agree with them, whether they're a friend or an expert.

This hypothesis could help explain why you might think one kind of car is safer than another, why everyone is wearing crop tops this summer, or why books that hit the New York Times bestseller list tend to stay there for a while. And once momentum gets started, it keeps on going, thanks to the bandwagon effect: the more people adopt an idea or belief, the more likely others will too. Simply having a sense that many people support an opinion or think a video is funny can cause others to retweet again and again.

But memes don't last forever, and the idea of an informational cascade can also explain why fads die—why yesterday's covfefe joke is today's…like, whatever that is by the time this is uploaded. The premise of an informational cascade is that many people's decisions are based on the research and thoughts of a few, hopefully well-informed people. But when a bandwagon grows, it doesn't increase the amount of knowledge that went into that first shareable thing.

Which means that receiving information that contradicts the idea—maybe a recall from that super safe car company or some evidence that a seemingly scientific fact was just a hyped-up rumor—can pretty easily dislodge it. Or when the novelty wears off, because even dramatic chipmunk isn't as hilarious when you've seen it 100 times, a meme might die a natural death. People are already jumping on the next bandwagon.

So, while there are many, many things on the Internet that remain mysterious, there is some sense to what goes viral. It's the stuff that makes us laugh, the stuff that makes us mad, and the stuff that people we trust tell us we should share. Which is why you should definitely share this video to everyone you know.

Yep, it sure is satisfying when you share our videos. Just watchin' that little ticker go up and the view counts get higher and higher. Ugh!

Can't get enough. Hey, I'd watch a video of it. You might even call it an oddly satisfying video.

But what is it that makes those videos so oddly satisfying in the first place? Here's some research for the next time you fall down that Internet rabbit hole. You've probably been around the Internet long enough to have stumbled upon one of those so-called “oddly satisfying” videos.

They're, like, ten-minute-long compilation clips of some seriously weird stuff, like foam being cut into pieces, or hands drawing perfect spirals, or machines slicing cheese. If you've never done it, you might be thinking there's no way that you would actually watch ten minutes of that, but these videos have millions of views, and once you start watching, you might find it kinda hard to stop. They're weirdly relaxing, and our brains love something about them.

We're still waiting for someone to publish a peer-reviewed study on these oddly satisfying videos. But in the meantime, there are a few connected ideas in psychology that might explain what's going on. One possibility is that watching these videos could be similar to mindfulness or flow.

You might've heard about mindfulness, which involves focusing on the present moment and acknowledging and accepting your thoughts and feelings. It's sometimes involved in meditation or yoga. Flow is a little different—it's a state of creative concentration that happens when an activity is at just the right level of difficulty.

You feel in control of your actions, lose sense of time, and enjoy what you're working on even if you aren't accomplishing a goal. Like an artist working on a painting or a writer caught up in their story or a video blogger editing until late, late at night. It's one of my favorite things about making videos.

These videos might do something similar, because they grab our attention and make us lose our sense of time and the outside world. It's a great feeling. It's not a perfect comparison, though, because mindfulness and flow are both characterized by deliberate action and control on our part, and watching these videos is pretty passive.

So some psychologists think there's another explanation:. Watching a project get completed in these videos—like seeing someone perfectly frost a cake—causes the same reaction in your brain as completing a goal in real life. When you finish a task, your brain releases dopamine, a chemical that plays an important role in your brain's reward and pleasure circuits.

In other words, getting stuff done literally feels good. And research also suggests that leaving things unfinished kinda drives us nuts. In a well-known study from 1927, 32 participants were given around 20 simple tasks, like solving puzzles and making figures out of clay.

They were allowed to finish some of the tasks, but others they had to abandon halfway through. After they'd worked on everything, they were asked to list off the tasks that they had been given. On average, they were almost twice as likely to remember something if they hadn't been allowed to finish it.

The idea that it's harder to forget about things we haven't finished, eventually became known as the Zeigarnik effect, named after the researcher who did these studies. And it's been replicated in other research since then. So you could argue that oddly satisfying videos have to do with getting something just right or with finishing a task.

Stopping in the middle of one will bother us all day—that's why it's so frustrating when a gif ends too soon. But watching something to the end triggers our sense of completion … even though we definitely are not checking things off our to-do list as we watch them. That explanation doesn't work for all satisfying videos, though.

Some of them are pretty random, like glass melting or things exploding. So another possibility is that there's something more fundamental about the videos that we like. They tend to be geometric and colorful, so maybe those colors and shapes are just appealing to us.

Psychologists still aren't sure which kinds of stimuli our brains prefer—or if there's even a universal set of preferences—but we do know there are some features we tend to like better than others. No one knows exactly why, but there's a long history of research showing that people prefer curved lines and circles to angled lines and polygons. We definitely like symmetry.

We find it super attractive and even use it to guess at a partner's potential ability to reproduce. We're also quick to spot it, and studies have shown we're better at remembering symmetrical objects and designs. We're really into patterns, too.

Some researchers argue that extreme pattern recognition is one of the defining capabilities of our brains, and that it developed as our brains evolved. So maybe the kinds of symmetrical, repetitive motions in oddly satisfying videos are the patterns our brains like. But again, we don't know for sure.

None of these ideas are perfect explanations—they're just things we know about our brains that could be involved somehow. All we know for sure is that millions of people agree that there is something about these videos that makes them oddly satisfying to watch. So even if you can't get no satisfaction about why these videos tickle your brain so good, you can get a whole bunch of it just by watching them.

And now, if you will excuse me, I'm going to go watch a machine knead some silicone, just over and over again. Couldn't put the clip in the video for you to watch, because that would be stealing. So, you have to go watch it too.

One of the most satisfying things I can think of—besides cage diving with great white sharks, or really just sharks in general—is watching a good YouTube video. But as with many things, the internet likes to see how far it can take things. It's almost like … a challenge.

If you've ever wondered why challenge videos are a thing that exist, here's one more video from Hank. It might seem a little 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 they have been 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 that what it really comes down to is an unfortunate combination of social media and developing brains.

You might think that you'd need to have half a brain to even attempt any of these challenges. And you would 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.

And I can 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 being made and others snipped. And this might result in, like, me going out in my friend's backyard and making a bomb, which was a bad idea.

Some areas of the brain 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 more prone to impulsive and risky behaviors.

And while teenage brains are favoring all of this dopamine-fueled risk taking, pruning and reshaping is still happening in the prefrontal cortex. That's the part of your brain that's 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—violence, 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 kids doing stupid stuff is nothing new. But social media is new, 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 was happening 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 the 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 any of 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. 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 an impulse.

So it's more than just a general predisposition to do 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 your 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 are all so desperately seeking. Of course, not every teenager was eating tide pods, by a long stretch.

And not every person eating a tide pod 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're watching, hey Drew!

That was fun. No, it's bad! As you can see, the internet can give us all kinds of insight into the ways our weird primate brains take in and process information.

And as psychologists keep investigating online spaces, we're just gonna keep discovering more and more. If you want to keep on learning more about these incredible, amazing organs we call brains, you can go to youtube.com/scishowpsych and subscribe to get new videos every week. [OUTRO ♪].