The teenage brain: Why some years are (a lot) crazier than others
Neurobiologist Robert Sapolsky explains how your first 25 years will shape the next 50.
Robert M. Sapolsky holds degrees from Harvard and Rockefeller Universities and is currently a Professor of Biology and Neurology at Stanford University and a Research Associate with the Institute of Primate Research, National Museums of Kenya. His most recent book is Behave: The Biology of Humans at Our Best and Worst.
ROBERT SAPOLSKY: Neurobiologically, the single most important fact about, say, a 20-year-old brain is the fact that almost all of it is already matured, fully wired up—myelinated, a jargon-y term for it. The reward dopamine system has been going full blast since somewhere around like early puberty. All of the brain is totally up to speed—except for the frontal cortex. Probably the most interesting fact about human development is that the frontal cortex is the last part of the brain to fully mature. It is not completely online until you're about 25 years old, which is mind-boggling to think about.
What does that explain? That explains why adolescents are adolescent in their behavior. The sensation-seeking and the risk-taking; the highs are higher and the lows are lower, because the steadying frontal cortical hand there isn't fully up to speed yet, and everything else is a gyroscope out of control. And that's where the impulsivity is from. And that's where the extremes of behavior, and that's why most crime is committed by people at a stage whose frontal cortex is not fully developed yet. That is why most people who do astonishing, wondrously self-sacrificial things don't have the frontal cortex that's fully in gear yet either, and it's not in a position to convince them yet, 'Ah, that's somebody else's problem. Look the other way.'
That's why young adults are exactly how they are. Because the frontal cortex isn't quite there yet, and what you have as a result is more adventurousness and more openness to novelty and more likelihood of seeing somebody who's very different as, in fact, not being that different after all. And more likely to grab a cudgel and smash in somebody's skull who happens to seem like a "Them". And everything, just the tone of everything, is pushed up.
One incredibly important implication of that is that if the frontal cortex is the last part of the brain to fully mature it means it's the part of the brain that is most sculpted by environment and experience—and least constrained by genes. And it's the most interesting part of the brain. Meanwhile, look at the other end of it. Look at 60-year-olds and what's going on there. If you are a 60-year-old human, or say a rat equivalent of a 60-year-old, you are far more closed to novelty than a 20-year-old, than an adolescent rat is. Take a rat, for example, and see at what points in life is it willing to try a new food. At exactly the equivalent of late teenage years, early adulthood, and then you're closed to novelty. Any species out there shows that pattern including humans. So a 60-year-old is resistant to change, is resistant to somebody else's novelty. A 60-year-old, unlike a 20-year-old, deals with stress in a very particular way. If you're 20, what stress management is about is trying to overcome the stressor and defeat it. If you're 60, what stress management is about is learning to accommodate what things you're not going to be able to change, and there's nothing you can do about the fact that your knees hurt like hell; it's accommodating, it's learning the difference between what you can change and what you can't.
If you're 20, there's nothing in the world you can't change. By the time you're 60, what intelligence is mostly about is crystallized, fact-based knowledge and crystallized strategies for dealing with that knowledge.
What a 20-year-old intelligence is about is fluid, improvising, changing of set, reversing of orders. All of that is a very, very different sort of picture. So 20- and 60-year-old brains and 20- and 60-year-old social worlds are remarkably different.
- The human brain isn't fully developed until 25 years of age. Everything is there except for the frontal cortex, which is the last thing to mature.
- An immature frontal cortex explains the spectrum of teenage behaviors: it's what makes adolescents adolescent, says Sapolsky. "The sensation-seeking and the risk-taking; the highs are higher and the lows are lower," he says. Teenagers are more adventurous and more heroic during this time—but can also be more violent and impulsive.
- Because your frontal cortex is the last part to develop "it's the part of the brain that is most sculpted by environment and experience—and least constrained by genes," Sapolsky says. That's great news! Your adventure levels, openness, experience, and influences at 25 years old will shape who you are when you're 60.
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How would the ability to genetically customize children change society? Sci-fi author Eugene Clark explores the future on our horizon in Volume I of the "Genetic Pressure" series.
- A new sci-fi book series called "Genetic Pressure" explores the scientific and moral implications of a world with a burgeoning designer baby industry.
- It's currently illegal to implant genetically edited human embryos in most nations, but designer babies may someday become widespread.
- While gene-editing technology could help humans eliminate genetic diseases, some in the scientific community fear it may also usher in a new era of eugenics.
Tribalism and discrimination<p>One question the "Genetic Pressure" series explores: What would tribalism and discrimination look like in a world with designer babies? As designer babies grow up, they could be noticeably different from other people, potentially being smarter, more attractive and healthier. This could breed resentment between the groups—as it does in the series.</p><p>"[Designer babies] slowly find that 'everyone else,' and even their own parents, becomes less and less tolerable," author Eugene Clark told Big Think. "Meanwhile, everyone else slowly feels threatened by the designer babies."</p><p>For example, one character in the series who was born a designer baby faces discrimination and harassment from "normal people"—they call her "soulless" and say she was "made in a factory," a "consumer product." </p><p>Would such divisions emerge in the real world? The answer may depend on who's able to afford designer baby services. If it's only the ultra-wealthy, then it's easy to imagine how being a designer baby could be seen by society as a kind of hyper-privilege, which designer babies would have to reckon with. </p><p>Even if people from all socioeconomic backgrounds can someday afford designer babies, people born designer babies may struggle with tough existential questions: Can they ever take full credit for things they achieve, or were they born with an unfair advantage? To what extent should they spend their lives helping the less fortunate? </p>
Sexuality dilemmas<p>Sexuality presents another set of thorny questions. If a designer baby industry someday allows people to optimize humans for attractiveness, designer babies could grow up to find themselves surrounded by ultra-attractive people. That may not sound like a big problem.</p><p>But consider that, if designer babies someday become the standard way to have children, there'd necessarily be a years-long gap in which only some people are having designer babies. Meanwhile, the rest of society would be having children the old-fashioned way. So, in terms of attractiveness, society could see increasingly apparent disparities in physical appearances between the two groups. "Normal people" could begin to seem increasingly ugly.</p><p>But ultra-attractive people who were born designer babies could face problems, too. One could be the loss of body image. </p><p>When designer babies grow up in the "Genetic Pressure" series, men look like all the other men, and women look like all the other women. This homogeneity of physical appearance occurs because parents of designer babies start following trends, all choosing similar traits for their children: tall, athletic build, olive skin, etc. </p><p>Sure, facial traits remain relatively unique, but everyone's more or less equally attractive. And this causes strange changes to sexual preferences.</p><p>"In a society of sexual equals, they start looking for other differentiators," he said, noting that violet-colored eyes become a rare trait that genetically engineered humans find especially attractive in the series.</p><p>But what about sexual relationships between genetically engineered humans and "normal" people? In the "Genetic Pressure" series, many "normal" people want to have kids with (or at least have sex with) genetically engineered humans. But a minority of engineered humans oppose breeding with "normal" people, and this leads to an ideology that considers engineered humans to be racially supreme. </p>
Regulating designer babies<p>On a policy level, there are many open questions about how governments might legislate a world with designer babies. But it's not totally new territory, considering the West's dark history of eugenics experiments.</p><p>In the 20th century, the U.S. conducted multiple eugenics programs, including immigration restrictions based on genetic inferiority and forced sterilizations. In 1927, for example, the Supreme Court ruled that forcibly sterilizing the mentally handicapped didn't violate the Constitution. Supreme Court Justice Oliver Wendall Holmes wrote, "… three generations of imbeciles are enough." </p><p>After the Holocaust, eugenics programs became increasingly taboo and regulated in the U.S. (though some states continued forced sterilizations <a href="https://www.uvm.edu/~lkaelber/eugenics/" target="_blank">into the 1970s</a>). In recent years, some policymakers and scientists have expressed concerns about how gene-editing technologies could reanimate the eugenics nightmares of the 20th century. </p><p>Currently, the U.S. doesn't explicitly ban human germline genetic editing on the federal level, but a combination of laws effectively render it <a href="https://academic.oup.com/jlb/advance-article/doi/10.1093/jlb/lsaa006/5841599#204481018" target="_blank" rel="noopener noreferrer">illegal to implant a genetically modified embryo</a>. Part of the reason is that scientists still aren't sure of the unintended consequences of new gene-editing technologies. </p><p>But there are also concerns that these technologies could usher in a new era of eugenics. After all, the function of a designer baby industry, like the one in the "Genetic Pressure" series, wouldn't necessarily be limited to eliminating genetic diseases; it could also work to increase the occurrence of "desirable" traits. </p><p>If the industry did that, it'd effectively signal that the <em>opposites of those traits are undesirable. </em>As the International Bioethics Committee <a href="https://academic.oup.com/jlb/advance-article/doi/10.1093/jlb/lsaa006/5841599#204481018" target="_blank" rel="noopener noreferrer">wrote</a>, this would "jeopardize the inherent and therefore equal dignity of all human beings and renew eugenics, disguised as the fulfillment of the wish for a better, improved life."</p><p><em>"Genetic Pressure Volume I: Baby Steps"</em><em> by Eugene Clark is <a href="http://bigth.ink/38VhJn3" target="_blank">available now.</a></em></p>
Scientists discover burrows of giant predator worms that lived on the seafloor 20 million years ago.
- Scientists in Taiwan find the lair of giant predator worms that inhabited the seafloor 20 million years ago.
- The worm is possibly related to the modern bobbit worm (Eunice aphroditois).
- The creatures can reach several meters in length and famously ambush their pray.
A three-dimensional model of the feeding behavior of Bobbit worms and the proposed formation of Pennichnus formosae.
Credit: Scientific Reports
Beware the Bobbit Worm!<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="1f9918e77851242c91382369581d3aac"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/_As1pHhyDHY?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
The idea behind the law was simple: make it more difficult for online sex traffickers to find victims.
- SESTA (Stop Enabling Sex Traffickers Act) and FOSTA (Allow States and Victims to Fight Online Sex Trafficking Act) started as two separate bills that were both created with a singular goal: curb online sex trafficking. They were signed into law by former President Trump in 2018.
- The implementation of this law in America has left an international impact, as websites attempt to protect themselves from liability by closing down the sections of their sites that sex workers use to arrange safe meetings with clientele.
- While supporters of this bill have framed FOSTA-SESTA as a vital tool that could prevent sex trafficking and allow sex trafficking survivors to sue those websites for facilitating their victimization, many other people are strictly against the bill and hope it will be reversed.
What is FOSTA-SESTA?<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="723125b44601d565a7c671c7523b6452"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/WBaqDjPCH8k?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>SESTA (Stop Enabling Sex Traffickers Act) and FOSTA (Allow States and Victims to Fight Online Sex Trafficking Act) were signed into law by former President Trump in 2018. There was some argument that this law may be unconstitutional as it could potentially violate the <a href="https://constitution.congress.gov/constitution/amendment-1/" target="_blank">first amendment</a>. A criminal defense lawyer explains this law in-depth in <a href="https://www.youtube.com/watch?v=RoWx2hYg5uo&t=38s" target="_blank" rel="nofollow">this video</a>. </p><p><strong>What did FOSTA-SESTA aim to accomplish?</strong></p><p>The idea behind the law was simple: make it more difficult for online sex traffickers to find victims. FOSTA-SESTA started as two separate bills that were both created with a singular goal: curb online sex trafficking. Targeting websites like Backpage and Craigslist, where sex workers would often arrange meetings with their clientele, FOSTA-SESTA aimed to stop the illegal sex-trafficking activity being conducted online. While the aim of FOSTA-SESTA was to keep people safer, these laws have garnered international speculation and have become quite controversial. </p><p><a href="https://www.businesswire.com/news/home/20180321006214/en/National-Anti-Trafficking-Coalition-Celebrates-Survivors-Senate-Passes" target="_blank" rel="noopener noreferrer">According to BusinessWire</a>, many people are in support of this bill, including the National Center for Missing and Exploited Children and World Without Exploitation (WorldWE). </p><p>"With the growth of the Internet, human trafficking that once happened mainly on street corners has largely shifted online. According to the National Center for Missing & Exploited Children, 73 percent of the 10,000 child sex trafficking reports it receives from the public each year involve ads on the website Backpage.com."</p><p>As soon as this bill was <a href="https://www.pivotlegal.org/sesta_fosta_censoring_sex_workers_from_websites_sets_a_dangerous_precedent" target="_blank" rel="noopener noreferrer">signed into law</a>, websites where sex workers often vetted and arranged meetings with their clients could now be held liable for the actions of the millions of people that used their sites. This meant websites could be prosecuted if they engaged in "the promotion or facilitation of prostitution" or "facilitate traffickers in advertising the sale of unlawful sex acts with sex trafficking victims." </p><p><strong>The bill's effects were felt around the world — from Canadians being unhappy with the impact of this American bill to U.K. politicians considering the implementation of similar laws in the future.</strong> </p><p>Heather Jarvis, the program coordinator of the Safe Harbour Outreach Project (SHOP), which supports sex workers in the St. John's area, <a href="https://www.cbc.ca/news/canada/newfoundland-labrador/heather-jarvis-website-shutdown-1.4667018" target="_blank" rel="noopener noreferrer">explained to CBC in an interview</a> that the American bill is impacting everyone, everywhere: "When laws impact the internet — the internet is often borderless — it often expands across different countries. So although these are laws in the United States, what we've seen is they've been shutting down websites in Canada and other countries as well."</p><p>Jarvis suggests in her interview that instead of doing what they aimed to do with the bill and improving the safety of victims of sex trafficking or sexual exploitation, the website shutdowns are actually making sex workers less safe. </p><p>While <a href="https://gizmodo.com/the-uk-wants-its-own-version-of-fosta-sesta-that-could-1827420794" target="_blank" rel="noopener noreferrer">one U.K. publication</a> refers to FOSTA-SESTA as "well-intentioned but ultimately deeply-flawed laws," it also mentions that politicians in the United Kingdom are hoping to pursue similar laws in the near future. </p>
Has FOSTA-SESTA done more harm than good?<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTUxMzY5Ny9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY2ODUyNDc4OX0.dSEEzcflJJUTnUCFmuwmPAIA0f754eW7rN8x6L7fcCc/img.jpg?width=1245&coordinates=-68%2C595%2C-68%2C595&height=700" id="69d99" class="rm-shortcode" data-rm-shortcode-id="734759fa254b5a33777536e0b4d7b511" data-rm-shortcode-name="rebelmouse-image" alt="sex worker looking online for a job" data-width="1245" data-height="700" />
Is this really going to help, or is this bill simply pushing sex work and sex-related content further into the dark?
Credit: Евгений Вершинин on Adobe Stock<p>While <a href="https://www.businesswire.com/news/home/20180321006214/en/National-Anti-Trafficking-Coalition-Celebrates-Survivors-Senate-Passes" target="_blank">supporters of this bill</a> have framed FOSTA-SESTA as a vital tool that could prevent sex trafficking and allow sex trafficking survivors to sue those websites for facilitating their victimization, many other people are strictly against the bill and hope it will be reversed.</p><p><strong>One of the biggest problems many people have with this bill is that it forces sex workers into an even more dangerous situation, which is quite the opposite of what the bill had intended to do.</strong> </p><p>According to <a href="https://www.theglobeandmail.com/canada/article-anti-trafficking-activists-cheer-but-sex-workers-bemoan-shutdown-of/" target="_blank" rel="noopener noreferrer">Globe and Mail</a>, there has been an upswing in pimps sending sex workers messages that promise work - which puts sex workers on the losing end of a skewed power-dynamic, when before they could attempt to safely arrange their own meetings online. </p><p><strong>How dangerous was online sex work before FOSTA-SESTA? </strong></p><p><a href="https://www.beyond-the-gaze.com/wp-content/uploads/2018/01/BtGbriefingsummaryoverview.pdf" target="_blank" rel="noopener noreferrer">The University of Leicester Department of Criminology</a> conducted an online survey that focused on the relative safety of internet-based sex work compared with outdoor sex work. According to the results, 91.6 percent of participants had not experienced a burglary in the past 5 years, 84.4 percent had not experienced physical assault in the same period, and only 5 percent had experienced physical assault in the last 12 months. </p><p><a href="https://www.pivotlegal.org/sesta_fosta_censoring_sex_workers_from_websites_sets_a_dangerous_precedent" target="_blank" rel="noopener noreferrer">PivotLegal</a> expresses concerns about this: "It is resoundingly clear, both from personal testimony and data, that attacking online sex work is an assault on the health and safety of people in the real world. In a darkly ironic twist, SESTA/FOSTA, legislation aimed at protecting victims of and preventing human trafficking for the purposes of sexual exploitation, will do the exact opposite."</p><p><strong>Websites are also being hypervigilant (and censoring more content than needed) because they can't possibly police every single user's activity on their platform.</strong> </p><p>Passing this bill meant any website (not just the ones that are commonly used by sex traffickers) could be held liable for their user's posts. Naturally, this saw a general "tightening of the belt" when it came to what was allowed on various platforms. In late 2018, shortly after the FOSTA-SESTA bill was passed, companies like Facebook slowly began to alter their terms and conditions to protect themselves. </p><p>Facebook notably added sections that express prohibited certain sexual content and messages:</p><p style="margin-left: 20px;"><em>"Content that includes an implicit invitation for sexual intercourse, which can be described as naming a sexual act and other suggestive elements including (but not limited to):</em></p><p style="margin-left: 20px;"><em>– vague suggestive statements such as: 'looking forward to an enjoyable evening'</em></p><p style="margin-left: 20px;"><em>– sexual use of language […]</em></p><p style="margin-left: 20px;"><em>– content (self-made, digital or existing) that possibly portrays explicit sexual acts or a suggestively positioned person/suggestively positioned persons."<br><br> </em></p><p>Additionally, sections like this were also added, prohibiting things that could allude to sexual activity: </p><p style="margin-left: 20px;"><em>"Content in which other acts committed by adults are requested or offered, such as:</em></p><p style="margin-left: 20px;"><em>– commercial pornography</em></p><p style="margin-left: 20px;"><em>– partners that share fetishes or sexual interests"</em></p><p>Facebook wasn't the only website to crack down on their policies — the Craigslist classifieds section being removed and Reddit banned quite a large number of sex-worker related subreddits. </p><p><strong>Is FOSTA-SESTA really helpful?</strong> </p><p>This is the question many people are facing with the FOSTA-SESTA acts being passed just a few years ago. Is this really going to help, or is this bill simply pushing sex work and sex-related content further into the dark? Opinions seem to be split down the middle on this — what do you think?</p>
A leading British space scientist thinks there is life under the ice sheets of Europa.
- A British scientist named Professor Monica Grady recently came out in support of extraterrestrial life on Europa.
- Europa, the sixth largest moon in the solar system, may have favorable conditions for life under its miles of ice.
- The moon is one of Jupiter's 79.
Neil deGrasse Tyson wants to go ice fishing on Europa<div class="rm-shortcode" data-media_id="GLGsRX7e" data-player_id="FvQKszTI" data-rm-shortcode-id="f4790eb8f0515e036b24c4195299df28"> <div id="botr_GLGsRX7e_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/GLGsRX7e-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/GLGsRX7e-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/GLGsRX7e-FvQKszTI.js"></script> </div>
Water Vapor Above Europa’s Surface Deteced for First Time<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="9c4abc8473e1b89170cc8941beeb1f2d"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/WQ-E1lnSOzc?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Answering the question of who you are is not an easy task. Let's unpack what culture, philosophy, and neuroscience have to say.
- Who am I? It's a question that humans have grappled with since the dawn of time, and most of us are no closer to an answer.
- Trying to pin down what makes you you depends on which school of thought you prescribe to. Some argue that the self is an illusion, while others believe that finding one's "true self" is about sincerity and authenticity.
- In this video, author Gish Jen, Harvard professor Michael Puett, psychotherapist Mark Epstein, and neuroscientist Sam Harris discuss three layers of the self, looking through the lens of culture, philosophy, and neuroscience.