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4 highlights from Stanford's Human Behavioral Biology course, available online for free
From understanding human aggression to epigenetics, Stanford University offers all 25 lessons of this fascinating course for free on YouTube.
- Stanford's Human Behavioral Biology course explores the interconnections between physiology and behavior.
- Most of the course is taught by Robert M. Sapolsky, a professor of biology, neurology, and neurosciences at Stanford, and also an author and contributor to Big Think.
- Check out some highlights from the course below.
Imagine a 40-year-old man in the U.S. who is leading a quiet, suburban life. He's been married 15 years and has two kids and two pets. One day at the office, a coworker says something about a baseball team, and our man takes exception. He punches his coworker in the face. This, according to everyone in the man's life, was unusual behavior. Then, three months later, his wife discovers he's been having an affair with a much younger woman. Finally, he absconds with thousands of dollars that he embezzled from his company, and his family never sees him again.
How could you explain what happened? A few possible options:
- He's a bonafide creep.
- He's going through a very immature mid-life crisis.
- He has a rare mutation in one gene in his brain.
This scenario is posed at the start of Stanford University's Human Behavioral Biology course, available for free on YouTube. The course is led by Robert M. Sapolsky, a professor of biology, neurology, and neurosciences at Stanford, and also an author and contributor to Big Think. Sapolsky notes that the behavior described above is exactly what you'd expect in somebody with a rare neurological disease caused by one genetic mutation.
Over 25 lessons, most of which clock in at around 90 minutes, the college course explores how physiology and behavior interact — or, how our thoughts, emotions, and memories can influence seemingly unrelated bodily processes, and vice versa. The entire course is available on this playlist, but listed below are a few highlights to get you started.
The limits of categorical thinking
In the first lesson of the course, Sapolsky quickly reads a bunch of phone numbers, and instructs the students to write down as many as possible. For the first few examples, Sapolsky breaks up the phone numbers into the familiar "123-4567" pattern of which we're accustomed. He then starts reading them in unusual patterns — "1-23-456-7" — in an attempt to confuse and disrupt categorical thinking patterns.
Sapolsky says that categorical thinking helps us make sense of the world and store information more easily. But he uses this example to get the class thinking about how paying too much attention to the boundaries in categorical thinking can cause you to lose sight of the big picture. (Sapolsky elaborates at 16:45 in the video.)
The "worst urban myth of evolution"
In the first lesson on behavioral evolution, Sapolsky introduces the class to applying Darwinian principles of evolution to behavior.
"The first thing we need to do is unlearn something we all learned back when, on all those National Geographic specials that would consistently teach us something about this aspect of evolution, and would always teach it to us wrong."
Another scenario: A herd of 2 million wildebeest is migrating toward greener pastures. The herd eventually comes to a river. It's teeming with crocodiles. The wildebeest stop. Then, one elderly wildebeest steps up to the riverbank, jumps into the water, and gets eaten by the crocodiles, creating an opportunity for the rest of the herd to safely cross.
Was this a heroic sacrifice? Sapolsky says that popular science programs like National Geographic have long claimed that animals tend to "behave for the good of the species," an idea described by group selection. But this is the "worst urban myth of evolution," he says.
If you look closely at the wildebeest scenario, you'd see something decidedly less heroic, the professor says: the herd is actually pushing the elderly wildebeest up to the front of the line. "All of the other ones are saying, 'Yeah, get the old guy on the river!' Sacrificing himself, my ass."
"Animals behave in order to maximize the number of copies of genes they leave in the next generation," Sapolsky continues. "Remember: not survival of the fittest, reproduction of the fittest."
What to ask about any scientific study
In 2007, scientists published a major study showing that first-borns tend to have higher IQs than their siblings. The researchers controlled for nearly everything you might think of: differences in parental investment, parents who only have one child, age of the children when tested, etc. Media outlets ran with study, but lost in much of the coverage was a simple question: How big of a difference did the study find? The answer: 2.3 points.
"You sneeze while you're taking an IQ test and have to wipe your nose for eight seconds afterward, and that's going to cost you 2.3 IQ points," Sapolsky says.
The study was a great example of how the results of a study can be impeccable and statistically reliable, and also unimportant. At the 9:30 mark in the 8th lesson, Sapolsky uses a "Chutes and Ladders" experiment to illustrate how to better interpret the results and methodology of scientific experiments.
Near the end of the course's first lesson on behavioral genetics, Sapolsky discusses how early experiences can shape long-lasting behavioral dispositions. These dispositions might appear to be genetically inherited. But Sapolsky notes that epigenetic research on rats shows that environmental factors — like mothering style — can influence how likely a pup is to express certain genes. Such genes might be responsible, say, for making receptors for stress hormones.
"Your early experience is going to cause life-long changes in your brain, which will make you more likely to reproduce the same experience for your offspring," Sapolsky says around 135:15 in the video below.
What's especially interesting is that this kind of epigenetic programming is reversible. Noting research conducted by Michael Meaney at McGill University's Douglas Research Centre, Sapolsky says:
"You have a baby rat who spends the first of its infancy with some totally terrible, negligent, distracted mom," but if you put that pup with a nurturing mom, "you can change the epigenetic pattern."
Sapolsky notes how this kind of epigenetic programming looks and operates similar to genetics.
"All of this has two themes has two themes going on: Early experience causing really persistent differences in how this stuff works long after, and experience later on having the potential to reverse some of this. All of this stuff, once again, [could be] mistaken for genetic. What we have here is what appears to be a genetic style of what sort of mother rat you are, and it's not genes, it's the mothering style setting up the offspring for being a similar type of mother."
To be sure, epigenetics is a complex field, and this is just a simple example of how the environment can influence gene expression. Throughout the entire course, Sapolsky routinely emphasizes that studying human behavior, or any scientific field, can be incredibly complex — so much so that it may seem like it's impossible to solve anything. But "even though it's complicated, you gotta do something," Sapolsky says.
Part of studying a complicated field requires accepting the limitations of your era, as Sapolsky describes with an analogy about archaeology:
"A wonderful cool thing I heard about in archaeology...[is that] when you excavate a site, what you're supposed to do is excavate about half of it," he says. "You leave the other half for people in the future, with better techniques and better understanding, and leave something in tact there to keep from your, sort of, blundering hands."
The course ends on a message about the assumed dichotomy between being compassionate and being scientific: "Go and do both," Sapolsky says.
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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>
It's hard to stop looking back and forth between these faces and the busts they came from.
- A quarantine project gone wild produces the possibly realistic faces of ancient Roman rulers.
- A designer worked with a machine learning app to produce the images.
- It's impossible to know if they're accurate, but they sure look plausible.
How the Roman emperors got faced<a href="https://payload.cargocollective.com/1/6/201108/14127595/2K-ENGLISH-24x36-Educational_v8_WATERMARKED_2000.jpg" ><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQ2NDk2MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyOTUzMzIxMX0.OwHMrgKu4pzu0eCsmOUjybdkTcSlJpL_uWDCF2djRfc/img.jpg?width=980" id="775ca" class="rm-shortcode" data-rm-shortcode-id="436000b6976931b8320313478c624c82" data-rm-shortcode-name="rebelmouse-image" alt="lineup of emperor faces" data-width="1440" data-height="963" /></a>
Credit: Daniel Voshart<p>Voshart's imaginings began with an AI/neural-net program called <a href="https://www.artbreeder.com" target="_blank">Artbreeder</a>. The freemium online app intelligently generates new images from existing ones and can combine multiple images into…well, who knows. It's addictive — people have so far used it to generate nearly 72.7 million images, says the site — and it's easy to see how Voshart fell down the rabbit hole.</p><p>The Roman emperor project began with Voshart feeding Artbreeder images of 800 busts. Obviously, not all busts have weathered the centuries equally. Voshart told <a href="https://www.livescience.com/ai-roman-emperor-portraits.html" target="_blank" rel="noopener noreferrer">Live Science</a>, "There is a rule of thumb in computer programming called 'garbage in garbage out,' and it applies to Artbreeder. A well-lit, well-sculpted bust with little damage and standard face features is going to be quite easy to get a result." Fortunately, there were multiple busts for some of the emperors, and different angles of busts captured in different photographs.</p><p>For the renderings Artbreeder produced, each face required some 15-16 hours of additional input from Voshart, who was left to deduce/guess such details as hair and skin coloring, though in many cases, an individual's features suggested likely pigmentations. Voshart was also aided by written descriptions of some of the rulers.</p><p>There's no way to know for sure how frequently Voshart's guesses hit their marks. It is obviously the case, though, that his interpretations look incredibly plausible when you compare one of his emperors to the sculpture(s) from which it was derived.</p><p>For an in-depth description of Voshart's process, check out his posts on <a href="https://medium.com/@voshart/photoreal-roman-emperor-project-236be7f06c8f" target="_blank">Medium</a> or on his <a href="https://voshart.com/ROMAN-EMPEROR-PROJECT" target="_blank" rel="noopener noreferrer">website</a>.</p><p>It's fascinating to feel like you're face-to-face with these ancient and sometimes notorious figures. Here are two examples, along with some of what we think we know about the men behind the faces.</p>
Caligula<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQ2NDk4Mi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY3MzQ1NTE5NX0.LiTmhPQlygl9Fa9lxay8PFPCSqShv4ELxbBRFkOW_qM/img.jpg?width=980" id="7bae0" class="rm-shortcode" data-rm-shortcode-id="ce795c554490fe0a36a8714b86f55b16" data-rm-shortcode-name="rebelmouse-image" data-width="992" data-height="558" />
One of numerous sculptures of Caligula, left
Nero<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQ2NTAwMC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1NTQ2ODU0NX0.AgYuQZzRQCanqehSI5UeakpxU8fwLagMc_POH7xB3-M/img.jpg?width=980" id="a8825" class="rm-shortcode" data-rm-shortcode-id="9e0593d79c591c97af4bd70f3423885e" data-rm-shortcode-name="rebelmouse-image" data-width="992" data-height="558" />
One of numerous sculptures of Nero, left
A popular and longstanding wave of thought in psychology and psychotherapy is that diagnosis is not relevant for practitioners in those fields.
Scientists regenerate damaged spinal cord nerve fibers with designer protein, helping paralyzed mice walk again.
- Researchers from Germany use a designer protein to treat spinal cord damage in mice.
- The procedure employs gene therapy to regenerate damaged nerve fibers that carry signals to and from the brain.
- The scientists aim to eventually apply the technique to humans.