The Teenage Brain Explained

Being a teenager is hard. And so is living with one, I’m told. No human gets to escape this moody, angsty, confusing phase And interestingly, such an extended adolescence is unique to humans. Other animals grow up a lot faster than we do. And you may think our teen years are just about streamlining bodies for baby making, but as it turns out, the storm of sex hormones that we associate with the teenage years, are only a small part of what’s really going on in the teenage body. Most of the action, it turns out, is happening in the brain. Until fairly recently, we thought that the brain finished the nuts and bolts of its development, by the time we started kindergarten. But really, when puberty starts, it undergoes massive remodeling. This amounts to several years of neural growing pains, as well as the other more visible growth that’s going on all over your body. So take heart! Whether you’re going through it now, or about to go through it, or count yourself among the veterans of that turbulent decade, know that the result of the teen years is a stronger, faster, more sophisticated brain. If there were someone that told me twenty years ago… Let’s start with that obvious scapegoat of adolescent anguish, hormones. That word itself, is kind of a lazy shorthand that people use to describe the chemicals that some glands secrete, that can affect our behavior. But the fact is, hormones have all kinds of jobs that have nothing to do with where you grow hair, or what turns you on, or whether you feel glum for no apparent reason Hormones keep your heart beating, and your body hydrated, and they make your organs grow, and make you grow bone, and muscle, and skin! What people actually mean when they talk about ‘teenage hormones’, are sex hormones. And yes, puberty involves a whole series of sex hormones storms, the first of which actually kicks in before you’re outta Primary School. That’s when the Adrenal glands star secreting androgens, which triggers the growth in activity of the skin’s sebaceous glands, making skin more oily. Soon enough, more apocrine or sweat glands get activated increasing body odor. Then comes the waves of hormonal agents that start activating the gonads. For boys, this influx of luteinizing hormones from the pituitary gland, get testosterone from the testes, and suddenly, that guy has up to fifty times more testosterone than he did before puberty. This also changes the shape of the male body, promoting hair growth, and building up lean muscle mass, just as the increased presence of estrogen in girls rearranges the deposition of their fats, stimulating the growth of breasts. Humans are actually lucky to experience the craziness of puberty only once, many other animals undergo multiple similarly intense hormonal rodeos as they enter sexually active periods, sometimes called the rot or heat, every new breeding season. Some male species completely stop eating during their breeding period, because they’re just that sex crazed. And yet all that said, teen are far less ruled in their hormones than you might think. There are other factors that play here. For example, your favorite moody teen may be by turns punchy, angry, depressed, or in a zombie like fog, because of their chronic lack of sleep. Sleep is vital to everyone, but it’s specially important for kids and teens, because it’s during sleep that your pituitary gland releases an essential growth hormone, necessary for development. A normal sleep cycle driven by circadian rhythm, is regulated by the daytime release of cortisol, which helps you wake up, and melatonin, which helps you wind down when it gets dark. But this biology of sleep timing changes as we age and as puberty begins, teens’ sleep clocks get pushed back. Most adults start producing melatonin 10 p.m. ish, but one study showed that teenagers don’t start producing melatonin until closer to 1am! This may be because puberty’s hormonal frenzy is stalling the release of melatonin, and could partly explain why so many teens stay up late, energized by the night, but had a really hard time rolling outta bed with the alarm. Of course it’s a bit of a chicken and egg deal, since watching reruns of The Simpsons, and playing Call o’ Duty late at night continues to stimulate the brain, which may further delay the release of melatonin. Still, some researchers are starting to advocate for pushing back high school start times in the morning, in the hopes of having more focused students. So we’ve got sex hormones changing the bodies, and a lack o’ sleep to contend with, but increasing evidences suggest that, there is something much bigger at work that’s making teenagers so ‘teenager-ry’. Their brains! It turns out that brains actually take longer than we thought, to fully mature. I don’t mean physical size – our brains are already about 95% full-sized by the time we’re just six – but more in the sense of the connections inside the brain. Adults – for the most part – know how to make decisions by evaluating choices, and weighting consequences. They do this with their prefrontal cortex, which is responsible for controlling impulses and emotions, and forming judgments. Its neurons chat with the neurons in other regions of the brain, responsible for – say it – memory or movement, through synapses. The thing is, teenage brains don’t quite work like this yet. The prefrontal cortex may not be fully developed until you’re mid-twenties, and teen synapses – those ”lines” of communication – are still growing, and specializing. They’re also – slow. As an adolescent brain keeps developing, its axons – the long ”tail-like” parts of the neurons that transmits signals to other neurons – become more and more insulated by a fatty layer called the ‘Myelin Sheath’. This padding greatly increases the cell’s transmission speed, and while it helps adults make faster decisions, it isn’t fully formed in teens. These changes occur slowly, beginning at the back o’ the brain, where the oldest and most fundamental brain parts reside, and slowly working its way forward to the more advanced and complicated brain bits. The prefrontal cortex is the last to be hooked up and shaped. So it’s important to keep in mind, that just because your favorite teenager stayed up until sunrise binge-watching ‘The Walking Dead’ the night before an exam, it doesn’t mean they’re dumb or lazy, their brain are just literally finishing being built. But at the same time, because all o’ this brain building’s just starting to peak, this is also, when the brain starts getting thinned out. You actually start losing connections that you don’t use enough, in a process called synaptic pruning – which has led to a theory that this is kind of a ‘use it or lose it’ phase. Meaning, adolescence could be an specially important time to use your brain – play an instrument; engage in sports; write poetry; learn language! Because by doing these things, you’re helping hardwire those synapses, and giving your brain topiary a lovely lasting shape. Whereas if you’re sitting around all day playing Candy Crush, those will be the connections that survive, which you don’t need… This shaping of the teen brain manifests itself in other ways too, like in teenage attitudes. A group of scientist at the McLean Hospital of Massachusetts, once hooked up a group of adults and a group of teens, to MRI devices and then asked them to identify a series of expressions on photographs of adults faces. Interestingly, while adults correctly identified one expression as fear, the teenagers thought the faces showed anger, surprise, or shock. They weren’t registering subtleties well. Not only that, but the MRI images showed that adults and teens responded with different parts of their brains. Adults, use the reasonable prefrontal cortex, while the teens mostly use the gut reaction, emotional amigdala, located farther back in the brain. Results like these might help explain why teenagers seem to experience frequent mood swings. For one, they tend to react quickly from the emotional part of their brain, without running those reactions by the more rational frontal cortex, and two, it could be that they’re just misreading expressions, and therefore the intentions behind them. The frontal cortex also helps people relate to, and understand each other, and you can imagine what happens when concern is misjudged as anger; or worry, as disappointment. The Fresh Prince has an entire song about it. But the truth is, as much as parents just don’t understand, teens don’t always understand either. When the emotional amigdala, and the more rational cortex aren’t fully hooked up yet, that can make it hard for teenagers to productively work through emotions. This kind of reactionary, impulsive behavior may also lead to more risk taking. Adolescence is the time when we’re most likely to experiment with whatever booze, or drugs is available, and unfortunately, it’s also the time our developing brains are most vulnerable to lasting effects Studies have shown that teens are more likely to become addicted to drugs and alcohol, than adults partly because their brains are more attuned to their reward centers. While the teenage prefrontal cortex is still developing, their ‘Nucleus Accumbens’, or ‘pleasure and reward zone’, forms early on. Neuroimaging studies have shown that when presented with a big potential reward, teen brains light up way more than kids or adults brains, but if the reward was small, teen brains hardly fired at all. So basically, give an adolescent a pat on the back, and you’ll get a shrug. Give them a hot date or a wining goal, and their brains light up like Vegas. This of course, does not always result in great judgment. A jacked up thrill-seeking impulse, combined with exquisite pang of peer pressure, plus a new driver’s license, new sex parts, and access to substances can lead to some not good results. But still, this long and some times tedious remodeling process that our bodies go through in the teenage years, isn’t all that. Many scientists have pointed out that our delayed adolescence lets our brains keep their flexibility longer, which Yeah, may make teens a little slow, but also more adaptable, as they prepare for the adult world. In this way, you can see teen impulsiveness as boldness; or independent thinking, and moodiness, as a source of new found empathy; and excitability, as passion. Which means, there’s a lot of awesome energy floating around out there ready to decrease all kinds of world sigh Thanks for watching the SciShow, and thanks specially to all of our subscribers on Subbable, who make this channel possible! 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100 thoughts on “The Teenage Brain Explained”

  1. Couldn't shock or fear kinda be the same thing? I wonder how they determine those a different things, at least for expressions on cards. It would be kinda obvious otherwise lol


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    EVPs are popular tobacco products among teenagers. A study has suggested that adolescent EVP users have been exhibiting a higher likelihood of indulging in several substance-use behaviours.


  3. I love this! Lots of different research included in a way that's friendly to teens and their parents. I wish you would not have chosen exclusively the girls with their games as the example of a brain wasted. Statistically, boys spend more time on games than girls. Examples of both would have been better.

  4. I was a shaken baby so the hormones in my body react at different times. I was the first girl in my class to get brests…. in 3rd grade. BUT things like always hungery, always tired, and body odder didnt hit me till recently… im 21 and its all very confusing since i "should" be done with all that. I believe that my brain wont be "done" till im atlest 30 instead of 26 because some things are just hitting me.

  5. all lies, every teen is afflicted with mental illness and must be medicated the rest of their lives with psychotropics lol

  6. What i know about the teenage human: Teenagers usually are the type of person that loves anime(a cliché as in The like/love of animated fox, Wolf or canine characters, usually looking like quick anime characters of foxes or wolves with big eyes and no pupils) And they are mostly not so easy to deal with, like for an example, My Stepmother, Mary has a daughter named Jadyn, she is A-L-W-A-Y-S in her bedroom with her door locked. In a word, she is grumpy at most, but that's the teenage mind for you. But she's not the only kid, There is also Zack, Chance and Eli to the family. But they are a Gargantuan mess!!!! Proof: Their mother's house is a big mess, dirty kitchen floor, cockroaches, Clothes strained all over the floor in the living room and a bunch of trash behind the couch and a bunch of chance's mistreated toys, his toy dinosaur is headless because chance didn't treat it very good at all, and crazy in the bedroom, the floors and walls are moldy, the bathroom is disgusting, the bathtub is full of rotten, dirty, flaked up toys, even Zack's bedroom is a freaking big mess and it Stinks! They barely throw their trash away, they mistreat the house and Mary is getting fed up with it. Teenagers usually love playing the common video games these days like Fortnite, Minecraft and Pokémon.

  7. Old people and te world: Let’s discriminate all teens that they do drugs and are a shame for society.
    Me: wow y’all messed up

  8. Wish I wasn’t a teen it Sucks and makes ADHD AWHOLE lot worse. Plz like if anyone agrees eh??????? I feel like I’m alone and a failure 😢😢

  9. Well who else is a teenager here?

    I am 17 now btw feels like my teenage years just flew by……
    Like or comment or something


  11. My few friends started to be so mean sometimes. I often get depression only because them. I also has chaotic mind and don't know what to do first. Being teeneger is hard

  12. Ill tell you something interesting about the human brain most people dont know their is actually a stage where between teenage years and also young adult years where some question their own sexuality gender and also some have intercourse with men and women to see what they like it sounds kind of far out their somewhere but their is a stage like that and all kinds of other messed up stuff that happens during adolcscent developement .

  13. All adults need to be reminded of this every day. School times must change for tweens, teens and kids. School times must allow parents to work without causing job loss, and it does cause job loss. Healthcare must also become a basic human right for this reason, it affects teachers, parents, students and society at large..

  14. most of these points are valid, but, It would be fascinating to do a study on teenagers raised in "normal" families and those who have had an abusive parent(s). To see what parts develope slower and what is sped up. Obviously, emotions would have grown faster and the prefrontal cortex would have to develop sooner in order for reasonable thinking (to avoid punishment) and in a lack of pleasure and reward that most teens seem to have an excess of, perchance it was delayed or diminished in the lack of rewards. IDK I'm also a teenager, but I thought it would be cool to know.

  15. I was a late bloomer, a docile teen, obeyed all the rules and did all my chores. I started rebelling in my 30s, against my wife, she sucks.

  16. I will never understand why older people have permanent grudges against teens. People for some reason love to forget what it’s like to be young, just because they’re past it now so they don’t need to care how others feel.

  17. How do you expect anything will go even remotely smoothly with having hundreds, maybe thousands, of people that have a war raging inside them being in one place for hours?

  18. I was never in to durgs. Smoking or drinking when i was a teen i did think about drinking before i turn to the drinking age in where i live but i was just never in to it

  19. So why don't schools start later when it's been shown that students get better grades, have less absenteeism/tardiness, and are better behaved?
    Because teachers want to get off work sooner!

  20. I'm 13 and I guess just starting and I don't feel like I have mood swings or anything. I feel like noone really spends 4 hours on homework, or at least I don't. I do try to utilise my critical learning period by learning Japanese, Cyrillic, the Arabic alphabet, drawing, the recorder and the. piano. Besides French, Ancient Greek, Latin, German, English, Dutch, Physics, PE, Economy, History, Geography, Chemistry, Mathematics, Music and Drawing.

  21. Can we please just change the school system,,,make our parents understand and get a free therapist please🙇‍♀️🙇‍♀️

  22. Teach: you nedda decide your career
    Me: I need more time
    Teach: You indecisive teenagers
    Me: at least I think my careers through

  23. My Small brain thinks it's right every single time, but maybe i should accept that i'm a stubid, lazy and moody teenager. Adults are always right after all.

  24. I’m such an immature 17 year old.
    When he said Pituitary Gland, all I thought of was “this is the pituitary gland, he may be small but he has biiiig plans” “goodbye childhood….” from Gravity Falls

  25. Can you please make videos for how your brain works and what changes it goes through in your 20s? Or better yet, for each decade/life period. That would be so great!!!!

  26. Adults don't seem to try and understand teens as individuals. They just see us as "horny, gum-smacking, dumb burdens" for the most part, while failing to acknowledge that we are PEOPLE, and we have different personalities.
    You treat us like kids, but expect us to behave like adults. How idiotic is that? You think all of us have the judgement of a sheep and are unable to have a mind of our own? Maybe if adults let us reason more frequently, instead of forcing their opinions on us, things would be different, but they're way too biased to realize that we're blamed for things we can't control whatsoever. Most of us are just trying to carry on in a world that oppreses and exploits on the youth.

  27. I feel for all teens, especially younger ones. Adults think you're stupid, and irresponsible. They don't even remember how hard it was to be a teen. So for you teens out there, it's okay to make mistakes, or not know what to do with you're life. It's true, you're parents don't understand, but that's okay, as long as you find people that do. I care for you all ✌ I'll be the one adult who will back you up 😀

  28. What if you run into the issue were you start seperating home and school? I have work I need to get done at home. But I'm never really able to stay focused on it. At school it's no problem.

  29. 7:10 I feel that when he says that, he is still being a teen himself. Tbh I used to think my parents didn’t understand, but through maturity I realized that a lot of the stuff I went through they also went through. Yes I’d agree not every decision they make is beneficial, so he does have a point, but still there’s a lot your parents understand that you may not think they do, it’s a matter of time that will get you through that phase. I’m 14 btw

  30. It’s so annoying seeing people my age claiming and self diagnosing themselves with depression. I understand it’s hard to tell but don’t downgrade other people’s actual possible depression with your “i have depression” and “people never understand”

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