I love this man. The world is a better place because of him. Thank you for making it possible for the rest of us to have a chance to listen to his lectures.
I'm still amazed for having the opportunity to see this classes here. There's no Black Mirror season that can overcome the existential feeling after seeing one of these lessons. Thank you Mr. Sapolsky!
"There's no Black Mirror season that can overcome the existential feeling after seeing one of these lessons." I think I know what you mean now, but reading this first was super weird. Thought you watched Black Mirror to take your mind off existentialism.
@Adrian Nguyen For both parents actually, because a more available second parent means less stress for the mother as well, and better bonding with the new born child for everybody.
Forever grateful to Dr. Sapolsky and Stanford for this priceless opportunity to learn. Watching these lectures makes me realise I haven't had a whole lot of good teachers in my life.
After listening to this talk one might come to the conclusion that maternal leave, before and after birth, would be a good idea because stress for the mother does seem to have an influence on the developing child.
While you have a fair point, there seems to be more to it from what I can tell. Remember that there are many types of stress, along with many different types of ways people *react* and *respond* to stress. There's eustress, too (happy/positive), like marriage, family reunions, a new dream job, etc., yet even the positive stress can have similar effects to the body on a chemical level as negative stress. Different hormones are generated in response to all of the different stresses, and the responses people have to all the stresses depend on a myriad of factors. Whether one's perspective is to view stress as a constructive opportunity for overcoming a challenge versus a debilitating and insurmountable obstacle; whether one under stress has a good support system composed of great friends/family/lovers versus a dysfunctional set of people who agitate that stress, versus having no support system at all; whether one under stress is of a higher economic class and can therefore afford more/better healthcare, vacations, quality food, dietary systems, classes, etc., versus a lower economic class with little if any access to the above and more; whether one's race, ethnicity, culture, family structure, or religion is the same or different from the majority of the social demographics and community around you *and* whether that difference or sameness has any potentially ugly consequences (racial hatred, religious bigotry, ethnic inequality, cultural insensitivity, intolerance of LGBTQ people, and even ignorance regarding immigration and emigration--regardless of country/nation)... (etc., etc.) As professor Sapolsky has explained in this fascinating course so far, there is no single "bucket" that provides the best convenient answer to human behavior. Prenatal environmental and sensory factors are another realm among many facets of the whole vastly-faceted topic. So, just as with many other policies in many other realms, maternity leave really ought to be a *choice* one can make and accept *without* academic or professional penalty, at least to be "fair" and account for the fact that people and their circumstances are so vast and varied. Admittedly, this particular lecture really got me thinking about how my mother's pregnancy might have been, and wishing I could ask her about it. If anyone out there is wondering the same stuff, don't wait to ask! Our parents don't stay around forever... Lastly, it's great to watch this lecture series with you all, whether you're watching now or had years ago. :-D
Yep. My OB blames my stress level at work on my severe oligo and therefore an emergent induction. This is just one example of course, but the U.S.’s idea of an adequate idea of maternity leave of 6 weeks after birth (and many resent even that) is cruel and unusual punishment for a health condition a woman “chooses to let affect her career.” Some women can and want to work up until the moment they pop; I thought I did, but my pregnancy was hard. I really wish I had had the option of antenatal leave like in Canada and Europe.
After introductions, both Congolias took the wrong freeway exit and fell in unexpected love with each other. They disguised themselves and ran away together to start a new life...
the idea that boys and girls are treated and raised the same at the time of middle school is so ridiculous i laughed out loud when the study claimed that. glad he addressed how ludicrous that was.
reminds me of how the academically gifted guys in my class would be offered more advanced math learning, but me who was also a top student but female often got brushed aside and told it was "too much" for me
Since I was a child, I always saw doctors and teachers like some of the best and and most valuable elements for our societies; until privatization (and corruption, on fashion this days ) started to infect those institutions.. So, this postings, free to watch for everyone, is a much needed renovation of faith. Thank you Stanford University. Thank you Professor Sapolsky. Love, Respect, Admiration, and Gratitude to our Good Educators.
"until privatization (and corruption, on fashion this days ) started to infect those institutions" In sad contrast, I remembered when it was all "good enough for government work". We used to make jokes about it. I remember Government schools that taught us not to question authority, to be obedient servants, to raise our hands and say "One" or "Two" to go to the bathroom. I live in a State with some of the most ruthless Teachers Unions in the US. Teachers who retired at fifty. Privatization is a form of fascism. Private prisons are nasty places.
28:11 Increased chances of developing Schizophrenia by the environment 58:06 Dutch Hunger Winter causing metabolic syndrome 1:08:22 Anxiety levels are dependant on fetal development, not genetics 1:18:27 Lamarckian Trait: environmental change on genes getting inherited
I came here from Russian channel Very Dider that translated all parts of these lections. Robert Sapolsky is the one of the best teacher I have ever met. It's enough ordinary comment, but the sense a little bit different. I haven't had the opportunity to be taught by some perfect teacher. Thank you, Robert, for your work very much. And thank a lot for interviews you give to channel Vert Dider regularly. Bless everyone!!!
lol I do something similar. I slide my phone under my pillow with the timer selected to stop when episode is over. Turn the volume up just enough that I can hear it and follow along. What’s equally important as the actual topic is the delivery. The voice and or cadence of lecturer/podcast host is key. Sapolsky lectures are golden, I would also suggest another podcast/channel that has become my go to for bedtime is “voices of the past.”
Look forward to listening to the podcasts direct from Stanford university. Makes me feel like I am part 〽️ of the class ! Thank you Professor Sapolsky.
I love how he completely demolishes all the methods people use to just assume it was genetic. No wonder people with more knowledge become less and less confident in the certainty of their positions.
heritability does mean genetic causality, that's the entire purpose of it. In twin adoption studies, we find that, despite being reared apart into different households, children grow up to be more similar to their biological relatives than their adoptive relatives based on a pattern of genetic similarity (ie. MZ siblings are more similar to each other than DZ siblings are). Sapolsky is arguing that environment can influence heritability which is true but in the case of twin studies, environments are controlled for and thus we get heritability estimates like 40 60 or 80 %. You can look into research on the Scarr-Rowe effect which is the lowering of heritability due to lower SES. It's failed replication alot and seems to not to be prevalent.
@@einmuffin6063 On average, the similarity between the personality of adopted children and their parents is around zero. Whatever those environmental influences are, it's not nurture.
@@einmuffin6063 The burden of proof is on those who believe pre-natal environment is a likely cause of within-between group differences. As Tom Franklin mentioned before, we see that twins reared apart into different households grow up to be more similar to their blood siblings than adoptive siblings.
I'm watching this guy on all my days off this weekend. Jesus, the data with the puberty and moms was like he was reading my mind on what information I wanted to hear next. What a great speaker. So fluid and calm.
TLDR: Genetic and environmental factors both play a role in influencing behavior, and can have long-lasting effects on physical and mental development, even across generations. 1. 00:00 🧬 Genes and environment both contribute to behavior, and can be studied by comparing monozygotic and dizygotic twins, as well as gender differences. 1.1 Behavior genetics is a field that can provide insight into the heritable components of behavior, but is also subject to criticism. 1.2 Behavior genetics looks for patterns of shared traits among individuals with differing degrees of shared genes to infer genetic influences. 1.3 By controlling for environment, we can examine relatives who share the same environment but differ in the amount of genes they share, to infer something about genetics. 1.4 Behavioral traits shared to a greater extent in monozygotic twins than dizygotic twins can be attributed to their greater genetic similarity and/or environmental similarity. 1.5 Monozygotic twins that split during the first five days after conception have their own placenta, while those that split between days five and 10 share one placenta, resulting in more similar IQs than bichorionic twins. 1.6 Genes and environment both play a role in producing gender differences, even when environment is the same. 2. 15:11 🧠 Adoption studies have found that having a biological parent with schizophrenia and being raised in an adoptive household with a schizophrenic parent increases the risk of a schizophrenia diagnosis by up to 17%. 2.1 Boys have higher average math scores than girls, with a 13:1 ratio at the highest IQ range. 2.2 A study published in Science found a 13:1 ratio of boys to girls in the highest math achievement, suggesting biological differences, but this was later disproven due to differences in educational environments. 2.3 Adoption studies compare shared traits between biological and adoptive parents to study the genetics of behavior. 2.4 Kety conducted a large study in Denmark to investigate the genetic component of schizophrenia in adopted individuals. 2.5 Having a biological parent with schizophrenia and being raised in an adoptive household with a schizophrenic parent increases the risk of a schizophrenia diagnosis by up to 17%. 2.6 The difference between 1 and 9 is about 10%. 3. 30:23 🧬 Comparing identical twins separated at birth can reveal the extent to which genetic factors influence traits such as IQ, introversion/extroversion, and aggression. 3.1 Kety's landmark study showed definitive evidence of a heritable basis to psychiatric disorders, leading to adoptive studies on heritability of various traits such as IQ, criminal behavior, and alcoholism. 3.2 Prenatal environment has long-term effects, and paternity uncertainty can complicate genetic studies attributing traits to biological parents. 3.3 Adoption is non-random, and identical twins separated at birth provide the best possible circumstance for behavior genetic studies. 3.4 Identical twins separated at birth provide a powerful approach to study the effects of environment on behavior, as seen in the bizarre stories of Tom Bouchard's 40 pairs of re-united twins. 3.5 Twin studies have found that IQ, introversion/extroversion, and aggression are all about 50% heritable. 3.6 Comparing monozygotic and dizygotic twins separated at birth can control for non-random placement in adoptive homes and reveal the extent to which identical genes influence traits. 4. 42:33 🤱 Prenatal environment can have long-lasting effects on physical and mental development, even influencing future generations. 4.1 All babies, regardless of sight, share the same motor pattern of smiling socially around the same age. 4.2 Environment does not begin at birth and prenatal environmental effects can be enormously influential. 4.3 The assumption that environment begins at birth has been challenged by recent research on prenatal environment and its effects on the fetus. 4.4 The age at which you reach puberty is affected by the age of the mother when she gave birth and the number of siblings in the womb, due to differing estrogen levels. 4.5 Prenatal stress can lead to a smaller brain, decreased learning abilities, increased anxiety, and difficulty recovering from stress as an adult. 4.6 Prenatal environment can cause non-genetic inheritance of traits, such as elevated glucocorticoid levels and a thinner cortex, which can be passed down for up to five generations. 5. 54:22 🤰 Fetuses exposed to famine during the third trimester of pregnancy develop a thrifty phenotype, leading to a 19-fold increased risk of obesity, hypertension, diabetes, and metabolic syndrome in adults, as well as anxiety disorders in their grandchildren. 5.1 During the Dutch Hunger Winter of 1944, 40,000 people starved to death due to food being diverted to Germany by the Nazis. 5.2 Fetuses exposed to famine during the third trimester of pregnancy develop a thrifty phenotype, which is a metabolic programming to store nutrients efficiently. 5.3 Individuals exposed to famine in the second to third trimester of fetal development have a 19-fold increased risk of obesity, hypertension, diabetes, and metabolic syndrome as adults. 5.4 The Dutch Hunger Winter study showed a 19-fold increase in anxiety disorders in adults due to elevated stress hormones during fetal life. 5.5 The grandchildren of Dutch Hunger Winter fetuses are born with a milder version of the Dutch Hunger Winter phenomenon due to their thrifty metabolism. 5.6 Epigenetic changes in genes related to insulin have been identified in Dutch Hunger Winter babies. 6. 01:02:27 🤰 Prenatal exposure to hormones, nutrition, and sensory stimulation can have multigenerational effects on traits. 6.1 Prenatal exposure to estrogen and phytoestrogens can increase the risk of estrogen-dependent breast cancer, and prenatal learning can be demonstrated in rats. 6.2 Fetuses can learn to recognize and prefer flavors they were exposed to in the womb, as well as hearing their mother's voice. 6.3 Newborns prefer hearing The Cat in the Hat, as measured by increased sucking motions, compared to a random collection of sentences, but the same effect does not occur when fathers read it aloud to the mother's belly. 6.4 Geneticists have found that prenatal effects of hormones, nutrition, and sensory stimulation can have multigenerational effects, and a study by Darlene Francis showed the power of these effects through an adoption study of rats bred for different levels of anxiety. 6.5 Early experience can influence the nature of a pregnancy, resulting in different anxiety levels in the fetus. 6.6 Cross-fostering studies suggest that prenatal environment has an effect on traits, and this is complicated by the possibility of misattributed paternity. 7. 01:10:31 🐣 Newborn chicks have a heritable tendency to peck at their feet, which can lead to changes in physical traits, personality, and even evolutionary legacies. 7.1 Mitochondria, the powerhouse of the cell, have their own DNA which is related to their function, supporting the hypothesis that they were once independent organisms. 7.2 At fertilization, the mother contributes a disproportionate share of DNA, including mitochondrial DNA and transcription factors, which can be used to trace evolutionary legacies. 7.3 Environmental toxins can disrupt the activity of transcription factors, resulting in heritable non-expression of a gene, creating a Lamarckian trait. 7.4 Environmental perturbations can cause Lamarckian inheritance of traits, ranging from subtle to substantial, that are not related to the amount of genes or DNA inherited from each parent. 7.5 Physical traits, such as height, that are heritable from parent to offspring can cause people to be treated differently, leading to changes in personality. 7.6 Newborn chicks have a heritable tendency to peck at their feet, which indirectly leads to their ability to find and eat grubs. 8. 01:26:06 🧠 Early experiences can cause lifelong changes in the brain, with multigenerational consequences. 8.1 Political party affiliation is 70% heritable, and is linked to a personality difference of how people feel about ambiguity, with conservatives being more ambiguity-averse. 8.2 Genetic differences in neurobiology of pain sensitivity can lead to heritability of aggression. 8.3 Epigenetic changes can cause lifelong differences in gene expression and multigenerational inheritance of non-genetic traits. 8.4 Picking up a rat for three minutes and putting it back has positive effects on its brain and health, while taking it away for an hour and a half has negative effects. 8.5 Variability in rat mothering styles is reflected in the neonatal handling phenomenon, which produces better outcomes in pups and is multigenerational. 8.6 Early experience can cause lifelong changes in the brain, which can be reversed by later experiences, and can have multigenerational consequences. Summary for th-cam.com/video/e0WZx7lUOrY/w-d-xo.html by www.eightify.app
taelyar chickens can be bitches. We’ve raised them. They pick at the weaker ones too pulling out their feathers probably so the rooster wont mate with it and wont pass on bad genes lol
Sometimes some scent in the room triggers some allergic reaction and I can't stop coughing out of nowhere. Cough cough cough. I Go out and drink water until it gets better. I wish I had the confidence of that person to just not care LOL
I live in Rexdale Toronto Canada. A really rough part of town. I don’t know how or why I’ve stumbled upon these videos and this class but I’m hooked. I’ve watched every lecture I have notes. I took a course at Stanford, that’s what I’m telling people now.
One correction: Sperm cells do have mitochondria that power up the flagellan motion. BUT everything below the Acrosome (Sperm "head") is left outside at the moment of fertilization.
@@katiie7 no. cellular conjugation is super rare, even in like cells. there would have to be a like cell and then it would probably only affect that single kind of cell in the body. like 1 in a quadrillion chance.
My grandmother was a supermom she took extreme care of my mom when she was pregnant . She took great measures to get water for my mom when we had drought .
I haven't slept in a couple night because I keep watching these lectures. woohoo sleep deprivation! just like a real live Stanford coed. I'm feeling smarter already!
One of the most amazing aspect of these lectures is how ideology influenced scientific thought but how science is constantly looking to correct that bias. The ball is now in your court, economics! How will you fix the pervasive (and often times perverse) biases in your field?
zanzeh teh hero Ha, the irony of your comment is that the scientific consensus supports the twin studies he dismisses. Think about it, his conclusion was that all of the numerous studies showing the same pattern really only prove that the pre-adoption environment typically has more of an impact on a human personality than all the environmental effects of the decades that follow combined. His best case scenerio still claims that many non-genetic, but unalterable biological processes, like prenatal hormone exposure (which in many cases are determined entirely by the mother's DNA) might be the cause. He's desperately trying to cling to a the Gouldian view that evolution didn't set any anchor points for our personalities, or "evolution stopped at our shoulders," as Judith Rich Harris mocks (whose work the prof cited out of context to support his theory). The reality is, that while our DNA does code for variable responses, there is a surprising amount of predictability for when, where and how genes will be coded. It's very unlikely that we are the only sexually dimorphic species on the planet that does not have any personality differences between the sexes. And all evidence suggests otherwise. Here's a better analysis from professors around the world: m.th-cam.com/video/41ryusHlrgw/w-d-xo.html
Great Moose Detective Umm, that’s exactly what Professor Sapolsky says. He never disputes the claim that there’s genetics factors for personality, he simply says there’s many variables to it that can all affect the way the genes are expressed. I have no idea what you’re talking about.
@@Psychol-Snooper He repeatedly suggests the studies are inconclusive and completely ignores their importance for the rest of the series. He could not have dismissed them anymore than he did. And, twin studies are a particularly poor place for the professor to highlight the importance of non-genetic factors. His need to insert such poor reasoning is itself demonstrative of the relative weakness of the point he makes.
Thank you, Prof Dr Sapolsky. I am grateful to you for having made your insightful lectures available to the public. I feel privileged to have had the opportunity to listen to this lecture (and others in the series).
Yes - great way to audit Stanford Biology. I have a Doctor of Music degree, I’m 55, and have been teaching guitar in college for decades, but now this makes me want to add another major! Haha!
This lectures are amazing. I could of never learned this at my community college, well probably, but the way that professor Sapolsky lectures is concise and to the point. Thank you for these lectures. They are priceless.
In the last ~20 years we have learned that epigenetic / non-genetic effects can be quite powerful as he mentions here. I think this realization has implications for how we should think about society and morality. If we know that (presumably innocent) children can suffer before being born due to the parent's poor conditions socioeconomically, I think we have a justification for a basic floor for well being (such as food and healthcare). That's because by denying these things to those in need, punishes innocent (unborn) children, and indeed makes it more likely to continue a negative cycle.
@@JohnMoseleyyou say your absolutely unfounded assumption all while you prefer the innocent unborn babies to be murdered so why do you try to act as if you care about the child?
@@laurawillingham1965 Because I do, Laura. I care about actual living children having access to good education, nutrition, and healthcare, and clean air and water, all things that are diminished by right-wing economic, environmental and social policies. It's amazing to me how many of the people behind these policies describe themselves as Christian. I don't believe that's what they are. If the Christ they claim to believe in and follow ever really did come back, he'd be as severely critical of them as he was of the Pharisees: 'They taught about God but did not love God - they did not enter the kingdom of heaven themselves, nor did they let others enter. They preached God but converted people to dead religion, thus making those converts twice as much sons of hell as they themselves were. ... They taught the law but did not practice some of the most important parts of the law - justice, mercy, faithfulness to God. ... They professed a high regard for the dead prophets of old, and claimed that they would never have persecuted and murdered prophets, when in fact they were cut from the same cloth as the persecutors and murderers: they too had murderous blood in their veins.' I can throw roughly the same question back at you: if you care so much about the wellbeing of children, do you support the kind of left-wing policies that are actually aimed at giving them a better life? Or do you only care about forcing women pregnant with foetuses that don't yet have consciousness to carry them to term whether they want to or not?
@@JohnMoseley again I say why do you try to PRETEND to care about the very ones you prefer to be murdered? You try to shift focus away from the fact that you would rather murder innocent unborn humans than allow them to live at all. You claim those who try to defend their lives wouldn't care about them as YOU are the one who wants them murdered! Your false and completely unfounded claim runs completely opposite of actual facts. You have to be completely oblivious to all reality if you haven't realized all the charitable work done by Christians in this nation and worldwide. Were it not for the services and resources provided by Christians, there would be FAR more suffering worldwide. YOU are the one who wants innocent humans murdered yet you want to view yourself as CARING???? Please!
@@laurawillingham1965 I'm sorry, I don't know how to explain my position to you any better than I have. Your anger doesn't strike me as very Christian. Try to be a bit more forgiving, as Christ teaches. He didn't say it would be easy, but it's worth it. Have a good day.
What people don't realize is that the "The Beatles" t-shirt he is wearing is increasing the evidence that this guy is the lost sibling of John Lennon. Pictures of Lennon with a fully grown beard let me arrive at no other conclusion.
@@martisole6249 I think the joke was just how random that fact was or that the point was going nowhere. Or maybe it was about triplets being armadillos lol.
I was trained by a theoretical biologist, but I am not a biologist or a psychologist. I like Dr. Sapolsky's lecturing method, it is dynamic and insightful.
It's interesting that most of the criticisms he mentions about the field are actually mentioned in Robert Plomin's 1990 book (and Plomin is probably *the* behaviour geneticist). The field isn't about elevating genes or environment in determining individual behaviour (which is mostly ridiculous) but asking about genetic contributions to individual differences. In a population, what amount of variance in that trait covaries with allelic variation?
I am leaning the same way. But I am also painfully aware that statistics is a heavily flawed concept. There is no winning. Perhaps truth will always both sides of a dice
@@4philipp yup, it's so interesting how two different people can "prove" something in opposite directions, both backed by statistics, and both can sound credible.
@@buttscooter420 he took that page down after Robert Downing Jr had to cancel his invitation due to the controversial primate psychology tweets Sapolsky made in 2007.
This is soo fascinating, Mr. Sapolsky explains everything perfectly and makes me just want to know more. Thanks for making this lessons open to access.
1:00:29 He means "Leningrad" (Currently St. Petersburg). Leningrad was under siege during World War II and the only way food was able to come into the city was in trucks on top of the ice which covered Ladoga lake in winter. This was a very dangerous endeavor as many trucks broke through the ice and drowned... Stalingrad (Currently Volgograd) was completely destroyed by German bombardment. It was Germans who were "under siege" or rather surrounded by the Red Army under Stalingrad, and faced starvation, but since they were mostly male and couldn't get pregnant - they don't matter as much to a Behavioral Biologist LOL OK I didn't really expect Sapolsky to know the World War II, The Eastern Front "bucket" ;-)
See, by the winter of '42, the whole city was surrounded by the massed Sixth Army. It was pressing and pressing. The Russians couldn't hold on much longer. Many wanted to submit. Those kids have no idea whatsoever of what went on at Stalingrad. Although I can in no way compare my struggle reading it with that of the Red Army, it has been a very big read.
Understanding Behavior Genetics and Genetic Influence on Behavior 00:16Introduction to behavior genetics and evolutionary psychology 01:36Shift to molecular biology and support for punctuated equilibrium 05:02Challenges and approaches in behavior genetics 08:28 Genetic and Environmental Influences on Identical and Fraternal Twins 16:51 Gender Differences in Math Skills and Genetic Influence 25:16 Genetic and Environmental Factors in Schizophrenia 33:41 Comparison of Genetic and Prenatal Effects in Behavior Genetics 42:06 Influence of Prenatal Environment on Behavioral Traits 50:31 Impact of Prenatal Stress and Nutrition on Brain Development and Metabolism 58:54 The Impact of Prenatal Programming on Adult Health 1:07:19 Genetic Inheritance and Prenatal Effects 1:15:41 Inheritance of Traits and Behavior: The Influence of Transcription Factors and Indirect Genetic Effects 1:24:05 Inheritance of Non-Genetic Traits and Epigenetic Changes 1:32:28 The Impact of Neonatal Handling on Maternal Behavior and Genetic Expression
The video script discusses the impact of neonatal handling on maternal behavior and its effects on offspring's size, health, and intelligence in rats. It also explores the influence of prenatal environment on behavioral traits, genetic inheritance, and epigenetic changes with multi-generational consequences. The script highlights the complexity of genetic and environmental influences on behavior and traits, including the impact of stress and hormonal exposure during fetal development. Understanding Behavior Genetics and Genetic Influence on Behavior Introduction to behavior genetics and evolutionary psychology Shift to molecular biology and support for punctuated equilibrium Challenges and approaches in behavior genetics Genetic and Environmental Influences on Identical and Fraternal Twins Identical twins share more genes and environment, while fraternal twins share less genes and environment. Behavioral traits in twins can be attributed to genetic influences and shared environment. Differences in genetic and environmental influences can affect traits and behaviors in twins. Gender Differences in Math Skills and Genetic Influence Study showed significant difference in average IQ between girls and boys, with boys having higher IQ. Boys also scored higher on math SATs, with a 13 to 1 ratio of boys to girls in highest math achievement. Adoption studies and genetic influence on schizophrenia were explored by Seymour Ketty at Harvard. Genetic and Environmental Factors in Schizophrenia Adopted individuals more likely to share schizophrenia trait with biological parent than adoptive parent. Study in Denmark showed a 9% incidence of schizophrenia in individuals with biological legacy of schizophrenia. Adoptive studies on heritability of various traits showed strong genetic component. Comparison of Genetic and Prenatal Effects in Behavior Genetics Prenatal effects can be measured by the percentage of shared traits with biological parents. Paternity uncertainty and non-random adoption placements complicate genetic studies. Identical twins separated at birth provide a powerful approach for behavior genetics studies. Comparison of monozygotic and dizygotic twins helps control for non-random adoption placements. Influence of Prenatal Environment on Behavioral Traits Behavioral traits can occur in the absence of learning or environmental experience. Examples of universal motoric patterns shared among all humans, regardless of prenatal environment. Prenatal environment, including hormonal exposure and maternal age, can influence later behavioral traits. Impact of Prenatal Stress and Nutrition on Brain Development and Metabolism Prenatal stress leads to smaller brain and thinner cortex in rats, affecting learning abilities and anxiety levels. Stress during pregnancy can result in smaller brain region that regulates stress response, leading to elevated glucocorticoid levels. Fetal exposure to starvation during Dutch hunger winter leads to metabolic programming, increasing risk of obesity and metabolic disorders in adulthood. The Impact of Prenatal Programming on Adult Health Prenatal programming occurs in the second to third trimester of fetal development. Exposure to stress hormones during fetal life can lead to increased likelihood of anxiety disorders as an adult. Prenatal exposure to estrogen derived from phytoestrogens may lead to a small but consistent increased risk of estrogen-dependent breast cancer later in life. Fetuses can learn and remember sensory experiences from the prenatal environment, impacting their preferences after birth. Genetic Inheritance and Prenatal Effects Prenatal environment influences anxiety levels, not genetic traits. Mitochondrial DNA is exclusively inherited from the mother, impacting genetic inheritance. Transcription factors in the cytoplasm of eggs come from the mother, affecting gene expression. Inheritance of Traits and Behavior: The Influence of Transcription Factors and Indirect Genetic Effects Transcription factors from the mother and father have different significance in gene expression. Environmental toxins can disrupt the activity of certain transcription factors, leading to non-genetic inheritance of traits. Indirect genetic effects, such as physical traits, can influence behavior and personality. Inheritance of Non-Genetic Traits and Epigenetic Changes Inheritance of social rank is not based on dominance traits, but on genes related to feather color. Newborn chicks' tendency to peck at their toes is a heritable trait, not the ability to find grubs. Political party affiliation, ambiguity tolerance, and aggression have genetic and indirect genetic influences. Epigenetic changes can lead to multi-generational inheritance of non-genetic traits. Neonatal handling of rats can influence brain size and life expectancy across generations. The Impact of Neonatal Handling on Maternal Behavior and Genetic Expression Neonatal handling causes dramatic changes in maternal behavior based on rat handling. Variation in rat mothering styles affects offspring's size, health, and intelligence. Epigenetic changes caused by maternal behavior have multi-generational consequences.
Love these lectures, 100p, as a dizygotic twin myself i can definitely confirm I grew up in a completely different environment than my twin, different primary school, different length of time spent w the rest of the family, more neglect etc
This guys is a great professor. This is my current ADHD obsession. Normally at this point I could have bailed out and found something else, but I can’t stop!!
omg he is fantastic! This is for myself personally the first time I have ever herd a person use a mathmatical approach towards actually proving how nature and nurture both play roles statistically towards a persons mental, and emotional health. I am sorry if i was not well spoken, or informed. This is just my opinion thus far.
I love this so much. esp, rn, I need a teaching and learning scientific community. I love going over fundamental courses, esp when they evolve so rapidly. my current solace is bracing my base knowledge so I can go buck wild on the virology ❤ thank you
Science update: though most mitochondria come from the mother, the father does contribute some mitochondria to the embryo, so mitochondrial dna is only overwhelmingly matrilineal not completely.
@@turbulence5691 Mostly. However we have learned there are exceptions to the rule that could change dates, rates, and how some haplotypes were inherited. They really don't have this new info assimilated into the big picture but our views have been rapidly shifting in molecular biology the whole time. Check this out. www.the-scientist.com/news-opinion/fathers-can-pass-mitochondrial-dna-to-children-65165
@@HotPinkst17thanks for the article man, btw i found a couple articles still talking abt Mitochondrial Eve from 2020 (the discovery came at around 2018 i think) www.thegreatcoursesdaily.com/mitochondrial-eve-the-mother-of-all-human-beings/ So I think for most practical purposes, they're maternal
Thanks for the update. I really wish they would do an updated version of this series, or maybe even just a video that explains all of the discoveries made since these videos were created.
Sapolsky mentions the adoption studies carried out in my home country, Denmark, by Thomas Bouchard. These dealt with schizophrenia. He fails to mention adoption studies carried out by Teasdale and Owen, also in Denmark, and later referred to by Bouchard. These were about intelligence. They were studies of adopted-away full-siblings, half-siblings, and unrelated children. All were boys, born between 1938 and 1947. Then they got the draft board records of intelligence tests of these boys when they were young adults (I know these intelligence tests; i was born in 1949 and tried the same tests). The data treatment gave as a result a 0.04 percent influence of environment, and a staggering 0.96 percent heritability of intelligence test results - the highest ever obtained. Why would intelligence be genetically determined to such a vast extent exactly in Denmark? The Danish society at that time was ethnically very uniform. Also, there had been a long period of social upward movement in the parent generation, so that everybody intelligent enough to rise socially, had done so. The intellectual environment was very uniform - very few children went to private schools. We all went to public schools, and the school system was the same everywhere. Nobody was very poor, and schools in relatively poor districts were no different form other schools. There was only one (public) television channel, so everybody saw the same programs in television. We all read the same Donald Duck magazines, etc. etc. The whole intellectual environment was extremely uniform. So how could there be any influence of environment on intelligence? Well, there was no influence, and practically all differences in intelligence were genetic. This, of course, would not be true in societies with large social differences. For instance, an earlier study (around 1950) of attained level of education in Norway showed a large effect of environment - children from remote parts of the vast country did not have the same chance of a higher education as children from larger cities, even if they were intelligent. So there was not yet the extreme social mobility which later characterized all Scandinavian countries. Now, why should Sapolsky have mentioned this? Because the students get the impression that intelligence is very much about environment, with the implications that differences in intelligence are unjust, some children getting better chances in life than others. But he Danish results indicate that you may eradicate all social injustice, and there will still remain large differences in intelligence, which cannot be removed in any way whatsoever. So even though part of the differences in intelligence in more socially stratified societies, like USA, may be ascribed to some sort of social injustice, the main point is that there will always remain large differences in intelligence which can never be removed, not matter what social engineering you may carry out.
Did they control for intelligence of the biological parents & household you grew up in? Even if society is uniform, parents aren't. If your household consists of more intelligent people, you learn more from them and can get better help with homework & co.
While I understand your point, there are too many aspects to be considered that aren't demonstrated to have been controlled for in your explanation of that study. Parents loading higher in different cognitive acuities, i.e. higher verbal intelligence, spatial-relational, etc, would have varying influences on their children. Personality of parents is another factor to be considered; more open parents versus more conscientious parents - children with parents who loaded higher in trait openness would perform better on most cognitive batteries (including creativity questionnaires) as these parents will be more likely to expose their children to more content of varying aspects. Temperamental variances explain for behavior and performance outcome better than IQ does. Loading higher in trait Conscientiousness has a strong correlation with performance (for example: fiscal success, grades) and very high levels of trait Openness has a negative correlation to grades but positive correlation with fiscal success. IQ can't be changed significantly by environment (no jumps in 10+ points, that hasn't been shown, but variations of up to 2 to 5 points have been) The environment will have a notable affect on the individual (diet, sleep quality...). But you can't transform someone with an IQ of 90 to someone with an IQ of 140.
@Bumblesnuff buffallobath The Rise of China directly contradicts the environmental hypothesis. China suffered Revolution Warlords, Invasion, Civil War, Invasion again, Mao, Famine, closure of universities and as soon as they adopted market economics, (and then not even fully ) they began developing. Why can't Mozambique do this? Why not Senegal? The Congo? Peru? Laos? Easy: they're dumb. Same for South Korea: war leveled every city in the country, then military dictatorship until 1990. Both countries developed because the people are smart. We have data from China 1986-87: their IQ was 99.7. Not even a generation after Mao and they were as smart as Western Europeans, even tho their environments were far poorer. Twin and adoption studies today show parenting doesn't matter. ENvironmental hypotheses fail to predict anything. Genetics does.
@@mykah3317 Yes.....5 to 10 points on IQ are negligible. In the 60s and70s we tried to develop culture Free IQ tests in hopes that certain populations would then score much higher than on the Weschler or Stanford Binet...scores were not higher in the populations when those tests were used. Then we spent decades trying to social engineer smarter school children through Head Start programs...millions upon millions of dollars spent high amounts of energy spent on follow up studies were we able to raise IQ and also academic achievement but enhancing environment.nooooo. THere was a SMALL positive effect for two years five years later the effect was gone. Huge energy spent because se oh so WANTED a,different outcome.
“Boys in the Johns Hopkins Center for Talented Youth Program had higher math aptitude and were vastly overrepresented at the highest echelons of scores” I remember going to that program myself, another problem with this study is that using those scores is NOT anything even remotely resembling a randomized sample, it’s kids with very rich parents who were normally selected at an early age for “gifted” programs.
(50:00) When the fetus is exposed to stress hormones (mother is stressed) it can cause the brain to be smaller- especially the part which turnes off the stress response - more prone to anxiety - problems with learning
Another issue is that most non-hearing people are not completely deaf. They can hear their own voice. They can hear loud low frequency sounds such as music, explosions, etc. truly deaf people, who have no perception of sound whatsoever are fairly rare.
These lectures are qmazing. Thank, you, Stanford University, for uploading them for us. Dr Sapoksky is a very special kind of lecturer. If course, I'd only expect the highest standards from Stanford. In around 2007 I downloaded a series of lectures on the Historical Jesus by a Professor Sheehan of Stanford. They were the most interesting set of talks and also of the highest quality.
Science evolves. We have to remember that each discovery was groundbreaking at the time. The more data is available the more nuanced the research can continue
So incredibly interesting, I kept having memory flashbacks of several animal baby cases that I have experienced. I have seen good and bad cow moms, good and bad cat moms, I've had abandoned calves and kittens being hand reared, I've had adoptees of kittens and heard of adoptees of calves which I hope to witness sometime. I have had calves stay with mothers but be support fed by bottle in the first 2 weeks because of nursing issues so they were handled as young but not later. I've had newborn calves imprint on me as I saved their life over the span of several hours, I have seen calves where they lost the mother before weaning age, I have also seen calves stay with mom too long as well seen lots of twins, I've seen the passing down of stress sensitivity... it goes on and on and I remember so many effects on developing personality from all these situations. I keep my eyes on differences and it interests me deeply!
A behavior like whomever is clicking their pen neurotically while recording this. But I digress, just happy to be given these sit ins in the first place. Namastay
His collection of lectures is responsible for millions of us who didn't go to college, to go to college, at least for this series. Does anyone have the list of books that he mentioned for each assignment?
More ones, more ones? Ok, that was good grammar. More ones. Haha, love this dude. I'm totally amazed by his way of explaining the complex studies in a playful manner.
![BOWKYLION - วิงวอน (ex-change) [Official MV]](http://i.ytimg.com/vi/cLdnZWDaO-w/mqdefault.jpg)
I love this man. The world is a better place because of him. Thank you for making it possible for the rest of us to have a chance to listen to his lectures.
Lies again? Wolves British German
@@NazriB ocoxcoxoxocoocgx
@@Ruthybwn what's your insta?
@@NazriBput the drugs down, obese person
I love how Robert everytime he introduces a new way of genetic research he hypes up as much as posible only for demolishing it a minute later
I know it’s like a roller coaster ride. A really fun one.
He really knows how to create an action-packed plot with this content.
I like his way of teaching
helps me learn, and know to question my sources even when this is the best knowledge i have right now:D
He's honest about Science.... he does not worship Science, he uses science.
I'm still amazed for having the opportunity to see this classes here. There's no Black Mirror season that can overcome the existential feeling after seeing one of these lessons. Thank you Mr. Sapolsky!
Dr. Sapolsky
@@martys9972 Princess Sapolsky
"There's no Black Mirror season that can overcome the existential feeling after seeing one of these lessons." I think I know what you mean now, but reading this first was super weird. Thought you watched Black Mirror to take your mind off existentialism.
Ve4ry true, We are extremely lucky.
@Adrian Nguyen For both parents actually, because a more available second parent means less stress for the mother as well, and better bonding with the new born child for everybody.
Forever grateful to Dr. Sapolsky and Stanford for this priceless opportunity to learn. Watching these lectures makes me realise I haven't had a whole lot of good teachers in my life.
Him telling me I am a female rat fetus: Me nodding in total agreement: of course what else would I be
😂
Thick.
Yes ahahahahaha
Wtf is wrong with you? xD
@Abdullah Lochlan Get blocked scam spammer. xD
After listening to this talk one might come to the conclusion that maternal leave, before and after birth, would be a good idea because stress for the mother does seem to have an influence on the developing child.
That thought did cross my mind
+DeletedDelusion something Sanders is adamantly calling for
While you have a fair point, there seems to be more to it from what I can tell. Remember that there are many types of stress, along with many different types of ways people *react* and *respond* to stress. There's eustress, too (happy/positive), like marriage, family reunions, a new dream job, etc., yet even the positive stress can have similar effects to the body on a chemical level as negative stress.
Different hormones are generated in response to all of the different stresses, and the responses people have to all the stresses depend on a myriad of factors. Whether one's perspective is to view stress as a constructive opportunity for overcoming a challenge versus a debilitating and insurmountable obstacle; whether one under stress has a good support system composed of great friends/family/lovers versus a dysfunctional set of people who agitate that stress, versus having no support system at all; whether one under stress is of a higher economic class and can therefore afford more/better healthcare, vacations, quality food, dietary systems, classes, etc., versus a lower economic class with little if any access to the above and more; whether one's race, ethnicity, culture, family structure, or religion is the same or different from the majority of the social demographics and community around you *and* whether that difference or sameness has any potentially ugly consequences (racial hatred, religious bigotry, ethnic inequality, cultural insensitivity, intolerance of LGBTQ people, and even ignorance regarding immigration and emigration--regardless of country/nation)... (etc., etc.)
As professor Sapolsky has explained in this fascinating course so far, there is no single "bucket" that provides the best convenient answer to human behavior. Prenatal environmental and sensory factors are another realm among many facets of the whole vastly-faceted topic. So, just as with many other policies in many other realms, maternity leave really ought to be a *choice* one can make and accept *without* academic or professional penalty, at least to be "fair" and account for the fact that people and their circumstances are so vast and varied.
Admittedly, this particular lecture really got me thinking about how my mother's pregnancy might have been, and wishing I could ask her about it. If anyone out there is wondering the same stuff, don't wait to ask! Our parents don't stay around forever...
Lastly, it's great to watch this lecture series with you all, whether you're watching now or had years ago. :-D
+Galactoid Overdos
Yep. My OB blames my stress level at work on my severe oligo and therefore an emergent induction. This is just one example of course, but the U.S.’s idea of an adequate idea of maternity leave of 6 weeks after birth (and many resent even that) is cruel and unusual punishment for a health condition a woman “chooses to let affect her career.” Some women can and want to work up until the moment they pop; I thought I did, but my pregnancy was hard. I really wish I had had the option of antenatal leave like in Canada and Europe.
"People who are taller are treated better and considered more attractive, he says bitterly"
I love this guy.
As a stout dwarvish human I found it funny
He could have said as bitterly something alike about serious scientists.
not sure this apply to girls too...
I love his dry sense of humor
Not if you’re a woman! Men and women will continuously feel intimidated and belittle your femininity .
He's just spewing knowledge at the pace of a train and I'm here absorbing it like sponge and it all feels good
@@VideographerExperience On the table and his laptop. He rarely looks at them though.
I agree "like sponge"... he makes it easy :)
@@nereidayares3387 bathing in the light of his insights
'Feynman effect'
@@fionafiona1146 900ㅐ00
Thank you for these lectures Robert Sapolsky and those people who enable us to watch these videos :)
Well said!
At least something initially funded using enormous US military budget that actually turned out to be useful to humans world-wide.
it is 2020 and sleep easy, 2016 friend... Trump is voted out. Easy, easy; I know.
I've taken so many classes at Stanford for FREE - Thanks youtube and Standford!
I love this lecturer. He's just fantastic to listen to. Keeps it interesting, fast paces but easy enough to keep up with.
Dr. Sapolsky, thanks VERY much for putting these lectures online! You are an incredibly engaging lecturer.
I'm now personally invested in the lives of Wolfie, Schmuel and both of their wives, named Congolia.
After introductions, both Congolias took the wrong freeway exit and fell in unexpected love with each other. They disguised themselves and ran away together to start a new life...
.
the idea that boys and girls are treated and raised the same at the time of middle school is so ridiculous i laughed out loud when the study claimed that. glad he addressed how ludicrous that was.
reminds me of how the academically gifted guys in my class would be offered more advanced math learning, but me who was also a top student but female often got brushed aside and told it was "too much" for me
Since I was a child, I always saw doctors and teachers like some of the best and and most valuable elements for our societies; until privatization (and corruption, on fashion this days ) started to infect those institutions.. So, this postings, free to watch for everyone, is a much needed renovation of faith. Thank you Stanford University. Thank you Professor Sapolsky. Love, Respect, Admiration, and Gratitude to our Good Educators.
Shut up, and just learn pronoun.
@@haze6647 8ggc7ggggggcgygģģygģgģģģgyģg
@@haze6647 7ģgģggggggggggggggguggg
"until privatization (and corruption, on fashion this days ) started to infect those institutions"
In sad contrast, I remembered when it was all "good enough for government work". We used to make jokes about it. I remember Government schools that taught us not to question authority, to be obedient servants, to raise our hands and say "One" or "Two" to go to the bathroom.
I live in a State with some of the most ruthless Teachers Unions in the US. Teachers who retired at fifty.
Privatization is a form of fascism. Private prisons are nasty places.
28:11 Increased chances of developing Schizophrenia by the environment
58:06 Dutch Hunger Winter causing metabolic syndrome
1:08:22 Anxiety levels are dependant on fetal development, not genetics
1:18:27 Lamarckian Trait: environmental change on genes getting inherited
Thank you so much! I love it when people do topical bookmarks -- I used to be a TH-cam bookmarker myself. I find it really helpful, and I thank you.
@@LJO_Hurts_Pianos Glad it helped : )
Thank you!
THANK YOU
16:27 Sex and IQ 1980s flawed experiment
I came here from Russian channel Very Dider that translated all parts of these lections. Robert Sapolsky is the one of the best teacher I have ever met. It's enough ordinary comment, but the sense a little bit different. I haven't had the opportunity to be taught by some perfect teacher. Thank you, Robert, for your work very much. And thank a lot for interviews you give to channel Vert Dider regularly. Bless everyone!!!
u cool
I'm binge-watching his videos. He's an amazing speaker.
You should check out Manolis Kellis on Lex Fridman's podcast, its biology but I love the way he talks
Sapolsky is a great lecturer! Very interesting stuff. Paradoxically I watch this before going to sleep, nothing gets me as tired as long lectures!!!
Cannot agree more love his video but most of the time I listen before bed. I learn so much from him.
lol I do something similar. I slide my phone under my pillow with the timer selected to stop when episode is over. Turn the volume up just enough that I can hear it and follow along. What’s equally important as the actual topic is the delivery. The voice and or cadence of lecturer/podcast host is key.
Sapolsky lectures are golden, I would also suggest another podcast/channel that has become my go to for bedtime is “voices of the past.”
Look forward to listening to the podcasts direct from Stanford university. Makes me feel like I am part 〽️ of the class ! Thank you Professor Sapolsky.
I love how he completely demolishes all the methods people use to just assume it was genetic. No wonder people with more knowledge become less and less confident in the certainty of their positions.
heritability does mean genetic causality, that's the entire purpose of it.
In twin adoption studies, we find that, despite being reared apart into different households, children grow up to be more similar to their biological relatives than their adoptive relatives based on a pattern of genetic similarity (ie. MZ siblings are more similar to each other than DZ siblings are).
Sapolsky is arguing that environment can influence heritability which is true but in the case of twin studies, environments are controlled for and thus we get heritability estimates like 40 60 or 80 %.
You can look into research on the Scarr-Rowe effect which is the lowering of heritability due to lower SES. It's failed replication alot and seems to not to be prevalent.
@@TheElderTK How do these twin adoption studies control for pre natal environment? How do they control for indirect genetic effects?
@@einmuffin6063 On average, the similarity between the personality of adopted children and their parents is around zero. Whatever those environmental influences are, it's not nurture.
@@einmuffin6063 The burden of proof is on those who believe pre-natal environment is a likely cause of within-between group differences.
As Tom Franklin mentioned before, we see that twins reared apart into different households grow up to be more similar to their blood siblings than adoptive siblings.
I'm watching this guy on all my days off this weekend. Jesus, the data with the puberty and moms was like he was reading my mind on what information I wanted to hear next. What a great speaker. So fluid and calm.
TLDR: Genetic and environmental factors both play a role in influencing behavior, and can have long-lasting effects on physical and mental development, even across generations.
1. 00:00 🧬 Genes and environment both contribute to behavior, and can be studied by comparing monozygotic and dizygotic twins, as well as gender differences.
1.1 Behavior genetics is a field that can provide insight into the heritable components of behavior, but is also subject to criticism.
1.2 Behavior genetics looks for patterns of shared traits among individuals with differing degrees of shared genes to infer genetic influences.
1.3 By controlling for environment, we can examine relatives who share the same environment but differ in the amount of genes they share, to infer something about genetics.
1.4 Behavioral traits shared to a greater extent in monozygotic twins than dizygotic twins can be attributed to their greater genetic similarity and/or environmental similarity.
1.5 Monozygotic twins that split during the first five days after conception have their own placenta, while those that split between days five and 10 share one placenta, resulting in more similar IQs than bichorionic twins.
1.6 Genes and environment both play a role in producing gender differences, even when environment is the same.
2. 15:11 🧠 Adoption studies have found that having a biological parent with schizophrenia and being raised in an adoptive household with a schizophrenic parent increases the risk of a schizophrenia diagnosis by up to 17%.
2.1 Boys have higher average math scores than girls, with a 13:1 ratio at the highest IQ range.
2.2 A study published in Science found a 13:1 ratio of boys to girls in the highest math achievement, suggesting biological differences, but this was later disproven due to differences in educational environments.
2.3 Adoption studies compare shared traits between biological and adoptive parents to study the genetics of behavior.
2.4 Kety conducted a large study in Denmark to investigate the genetic component of schizophrenia in adopted individuals.
2.5 Having a biological parent with schizophrenia and being raised in an adoptive household with a schizophrenic parent increases the risk of a schizophrenia diagnosis by up to 17%.
2.6 The difference between 1 and 9 is about 10%.
3. 30:23 🧬 Comparing identical twins separated at birth can reveal the extent to which genetic factors influence traits such as IQ, introversion/extroversion, and aggression.
3.1 Kety's landmark study showed definitive evidence of a heritable basis to psychiatric disorders, leading to adoptive studies on heritability of various traits such as IQ, criminal behavior, and alcoholism.
3.2 Prenatal environment has long-term effects, and paternity uncertainty can complicate genetic studies attributing traits to biological parents.
3.3 Adoption is non-random, and identical twins separated at birth provide the best possible circumstance for behavior genetic studies.
3.4 Identical twins separated at birth provide a powerful approach to study the effects of environment on behavior, as seen in the bizarre stories of Tom Bouchard's 40 pairs of re-united twins.
3.5 Twin studies have found that IQ, introversion/extroversion, and aggression are all about 50% heritable.
3.6 Comparing monozygotic and dizygotic twins separated at birth can control for non-random placement in adoptive homes and reveal the extent to which identical genes influence traits.
4. 42:33 🤱 Prenatal environment can have long-lasting effects on physical and mental development, even influencing future generations.
4.1 All babies, regardless of sight, share the same motor pattern of smiling socially around the same age.
4.2 Environment does not begin at birth and prenatal environmental effects can be enormously influential.
4.3 The assumption that environment begins at birth has been challenged by recent research on prenatal environment and its effects on the fetus.
4.4 The age at which you reach puberty is affected by the age of the mother when she gave birth and the number of siblings in the womb, due to differing estrogen levels.
4.5 Prenatal stress can lead to a smaller brain, decreased learning abilities, increased anxiety, and difficulty recovering from stress as an adult.
4.6 Prenatal environment can cause non-genetic inheritance of traits, such as elevated glucocorticoid levels and a thinner cortex, which can be passed down for up to five generations.
5. 54:22 🤰 Fetuses exposed to famine during the third trimester of pregnancy develop a thrifty phenotype, leading to a 19-fold increased risk of obesity, hypertension, diabetes, and metabolic syndrome in adults, as well as anxiety disorders in their grandchildren.
5.1 During the Dutch Hunger Winter of 1944, 40,000 people starved to death due to food being diverted to Germany by the Nazis.
5.2 Fetuses exposed to famine during the third trimester of pregnancy develop a thrifty phenotype, which is a metabolic programming to store nutrients efficiently.
5.3 Individuals exposed to famine in the second to third trimester of fetal development have a 19-fold increased risk of obesity, hypertension, diabetes, and metabolic syndrome as adults.
5.4 The Dutch Hunger Winter study showed a 19-fold increase in anxiety disorders in adults due to elevated stress hormones during fetal life.
5.5 The grandchildren of Dutch Hunger Winter fetuses are born with a milder version of the Dutch Hunger Winter phenomenon due to their thrifty metabolism.
5.6 Epigenetic changes in genes related to insulin have been identified in Dutch Hunger Winter babies.
6. 01:02:27 🤰 Prenatal exposure to hormones, nutrition, and sensory stimulation can have multigenerational effects on traits.
6.1 Prenatal exposure to estrogen and phytoestrogens can increase the risk of estrogen-dependent breast cancer, and prenatal learning can be demonstrated in rats.
6.2 Fetuses can learn to recognize and prefer flavors they were exposed to in the womb, as well as hearing their mother's voice.
6.3 Newborns prefer hearing The Cat in the Hat, as measured by increased sucking motions, compared to a random collection of sentences, but the same effect does not occur when fathers read it aloud to the mother's belly.
6.4 Geneticists have found that prenatal effects of hormones, nutrition, and sensory stimulation can have multigenerational effects, and a study by Darlene Francis showed the power of these effects through an adoption study of rats bred for different levels of anxiety.
6.5 Early experience can influence the nature of a pregnancy, resulting in different anxiety levels in the fetus.
6.6 Cross-fostering studies suggest that prenatal environment has an effect on traits, and this is complicated by the possibility of misattributed paternity.
7. 01:10:31 🐣 Newborn chicks have a heritable tendency to peck at their feet, which can lead to changes in physical traits, personality, and even evolutionary legacies.
7.1 Mitochondria, the powerhouse of the cell, have their own DNA which is related to their function, supporting the hypothesis that they were once independent organisms.
7.2 At fertilization, the mother contributes a disproportionate share of DNA, including mitochondrial DNA and transcription factors, which can be used to trace evolutionary legacies.
7.3 Environmental toxins can disrupt the activity of transcription factors, resulting in heritable non-expression of a gene, creating a Lamarckian trait.
7.4 Environmental perturbations can cause Lamarckian inheritance of traits, ranging from subtle to substantial, that are not related to the amount of genes or DNA inherited from each parent.
7.5 Physical traits, such as height, that are heritable from parent to offspring can cause people to be treated differently, leading to changes in personality.
7.6 Newborn chicks have a heritable tendency to peck at their feet, which indirectly leads to their ability to find and eat grubs.
8. 01:26:06 🧠 Early experiences can cause lifelong changes in the brain, with multigenerational consequences.
8.1 Political party affiliation is 70% heritable, and is linked to a personality difference of how people feel about ambiguity, with conservatives being more ambiguity-averse.
8.2 Genetic differences in neurobiology of pain sensitivity can lead to heritability of aggression.
8.3 Epigenetic changes can cause lifelong differences in gene expression and multigenerational inheritance of non-genetic traits.
8.4 Picking up a rat for three minutes and putting it back has positive effects on its brain and health, while taking it away for an hour and a half has negative effects.
8.5 Variability in rat mothering styles is reflected in the neonatal handling phenomenon, which produces better outcomes in pups and is multigenerational.
8.6 Early experience can cause lifelong changes in the brain, which can be reversed by later experiences, and can have multigenerational consequences.
Summary for th-cam.com/video/e0WZx7lUOrY/w-d-xo.html by www.eightify.app
My takeaway from this is that chickens are racist
taelyar chickens can be bitches. We’ve raised them. They pick at the weaker ones too pulling out their feathers probably so the rooster wont mate with it and wont pass on bad genes lol
And some mother rats have better souls.
It is generally thought that we humans are smarter than chickens. I don't think chickens have an opinion on the subject.
@@johnries5593 How can somebody be called smarter if there is no such a thing as free will.
Chickens are just the reproductive organs of chicken eggs. How can they be racist?
That person who's coughing uncontrollably should go get a check up
Put a mask on
Ten years ago, they're probably long dead now lol
I am over an hour in and was so engrossed I hadn't even noticed the coughing :)
Sometimes some scent in the room triggers some allergic reaction and I can't stop coughing out of nowhere. Cough cough cough.
I Go out and drink water until it gets better. I wish I had the confidence of that person to just not care LOL
What in the fuck possessed you to write something like that ? Genetics?
These old lectures are the best thing
The images this man puts in my mind are incredible. Better than any T.V. documentary for sure.
A lot of really great information to mull over. Dr. Sapolsky is brilliant!
I live in Rexdale Toronto Canada. A really rough part of town. I don’t know how or why I’ve stumbled upon these videos and this class but I’m hooked. I’ve watched every lecture I have notes. I took a course at Stanford, that’s what I’m telling people now.
It’s part of their program, pray for you to make it out!!!
@@martind2731 elaborate please
One correction:
Sperm cells do have mitochondria that power up the flagellan motion. BUT everything below the Acrosome (Sperm "head") is left outside at the moment of fertilization.
VaeSapiens serious question, would a female be taking on his genes essentially if absorbing the sperm?
@@katiie7 no. cellular conjugation is super rare, even in like cells. there would have to be a like cell and then it would probably only affect that single kind of cell in the body. like 1 in a quadrillion chance.
@@katiie7 There are some rare cases of mitochondrial genes inherited from father, but I have never heard of the mechanism or if the process is known.
@@vodrzlo yeah, seems possible ... look: www.the-scientist.com/news-opinion/fathers-can-pass-mitochondrial-dna-to-children-65165
Females do better n math if an application is used.
My grandmother was a supermom she took extreme care of my mom when she was pregnant . She took great measures to get water for my mom when we had drought .
It doesn't matter what I fall asleep watching, this guy always ends up on my TV.
I haven't slept in a couple night because I keep watching these lectures. woohoo sleep deprivation! just like a real live Stanford coed. I'm feeling smarter already!
One of the most amazing aspect of these lectures is how ideology influenced scientific thought but how science is constantly looking to correct that bias. The ball is now in your court, economics! How will you fix the pervasive (and often times perverse) biases in your field?
zanzeh teh hero
Ha, the irony of your comment is that the scientific consensus supports the twin studies he dismisses. Think about it, his conclusion was that all of the numerous studies showing the same pattern really only prove that the pre-adoption environment typically has more of an impact on a human personality than all the environmental effects of the decades that follow combined. His best case scenerio still claims that many non-genetic, but unalterable biological processes, like prenatal hormone exposure (which in many cases are determined entirely by the mother's DNA) might be the cause.
He's desperately trying to cling to a the Gouldian view that evolution didn't set any anchor points for our personalities, or "evolution stopped at our shoulders," as Judith Rich Harris mocks (whose work the prof cited out of context to support his theory).
The reality is, that while our DNA does code for variable responses, there is a surprising amount of predictability for when, where and how genes will be coded.
It's very unlikely that we are the only sexually dimorphic species on the planet that does not have any personality differences between the sexes. And all evidence suggests otherwise.
Here's a better analysis from professors around the world:
m.th-cam.com/video/41ryusHlrgw/w-d-xo.html
Great Moose Detective
Umm, that’s exactly what Professor Sapolsky says. He never disputes the claim that there’s genetics factors for personality, he simply says there’s many variables to it that can all affect the way the genes are expressed. I have no idea what you’re talking about.
This is not science. This is bullshit
@@awhodothey Did he dismiss the studies? I took that he was just giving background of interdisciplinary disputes.
@@Psychol-Snooper He repeatedly suggests the studies are inconclusive and completely ignores their importance for the rest of the series. He could not have dismissed them anymore than he did.
And, twin studies are a particularly poor place for the professor to highlight the importance of non-genetic factors. His need to insert such poor reasoning is itself demonstrative of the relative weakness of the point he makes.
I really enjoy this prof. Very easy to follow; good genes in jeans...he works beside, not above, his pupils. Very refreshing. :)
The situation for defending environmental factors on behavioral outcomes has certainly shifted in narrative since when this lecture was published.
Thank you, Prof Dr Sapolsky. I am grateful to you for having made your insightful lectures available to the public. I feel privileged to have had the opportunity to listen to this lecture (and others in the series).
This professor is amazing. He teaches the lecture in a away that capture your attention
This course is awesome, for no credit. I'm a physician and enjoy this kind of subject. Appreciate the Prof Sense of Humor :)
I was thinking of sharing this particular lecture with my PCP
Yes - great way to audit Stanford Biology. I have a Doctor of Music degree, I’m 55, and have been teaching guitar in college for decades, but now this makes me want to add another major! Haha!
These lectures are a gift to humanity.
Cant.... stop.... listening....
We get all the juicy info that these studies took years to obtain. So amazing.
This lectures are amazing. I could of never learned this at my community college, well probably, but the way that professor Sapolsky lectures is concise and to the point. Thank you for these lectures. They are priceless.
Well, it is Stanford University, so don’t feel too bad about that.
This is what a knowledgeable and talented college professor does. Better pay attention!
I have woken up to this man spitting his knowledge through my tv speakers many times…
And I’m not saying it’s a bad thing
In the last ~20 years we have learned that epigenetic / non-genetic effects can be quite powerful as he mentions here. I think this realization has implications for how we should think about society and morality. If we know that (presumably innocent) children can suffer before being born due to the parent's poor conditions socioeconomically, I think we have a justification for a basic floor for well being (such as food and healthcare). That's because by denying these things to those in need, punishes innocent (unborn) children, and indeed makes it more likely to continue a negative cycle.
Whereas, to be blunt, 'pro-life' right-wingers want to preserve only the foetus's right to life, without any guarantee of its quality of life.
@@JohnMoseleyyou say your absolutely unfounded assumption all while you prefer the innocent unborn babies to be murdered so why do you try to act as if you care about the child?
@@laurawillingham1965 Because I do, Laura. I care about actual living children having access to good education, nutrition, and healthcare, and clean air and water, all things that are diminished by right-wing economic, environmental and social policies. It's amazing to me how many of the people behind these policies describe themselves as Christian. I don't believe that's what they are. If the Christ they claim to believe in and follow ever really did come back, he'd be as severely critical of them as he was of the Pharisees:
'They taught about God but did not love God - they did not enter the kingdom of heaven themselves, nor did they let others enter.
They preached God but converted people to dead religion, thus making those converts twice as much sons of hell as they themselves were.
...
They taught the law but did not practice some of the most important parts of the law - justice, mercy, faithfulness to God.
...
They professed a high regard for the dead prophets of old, and claimed that they would never have persecuted and murdered prophets, when in fact they were cut from the same cloth as the persecutors and murderers: they too had murderous blood in their veins.'
I can throw roughly the same question back at you: if you care so much about the wellbeing of children, do you support the kind of left-wing policies that are actually aimed at giving them a better life? Or do you only care about forcing women pregnant with foetuses that don't yet have consciousness to carry them to term whether they want to or not?
@@JohnMoseley again I say why do you try to PRETEND to care about the very ones you prefer to be murdered? You try to shift focus away from the fact that you would rather murder innocent unborn humans than allow them to live at all. You claim those who try to defend their lives wouldn't care about them as YOU are the one who wants them murdered! Your false and completely unfounded claim runs completely opposite of actual facts. You have to be completely oblivious to all reality if you haven't realized all the charitable work done by Christians in this nation and worldwide. Were it not for the services and resources provided by Christians, there would be FAR more suffering worldwide. YOU are the one who wants innocent humans murdered yet you want to view yourself as CARING???? Please!
@@laurawillingham1965 I'm sorry, I don't know how to explain my position to you any better than I have. Your anger doesn't strike me as very Christian. Try to be a bit more forgiving, as Christ teaches. He didn't say it would be easy, but it's worth it. Have a good day.
What people don't realize is that the "The Beatles" t-shirt he is wearing is increasing the evidence that this guy is the lost sibling of John Lennon. Pictures of Lennon with a fully grown beard let me arrive at no other conclusion.
98% genetic pair lol
Such a fascinating lecture.
"What we're going to pick up with on Wednesday .. make the last two hours basically irrelevant" nice one :D
Freaking sapolsky. "Armadillos give birth to 4 identical offspring at once. ....okay." :)
i didn't get it xd
@@martisole6249 I think the joke was just how random that fact was or that the point was going nowhere. Or maybe it was about triplets being armadillos lol.
I was trained by a theoretical biologist, but I am not a biologist or a psychologist.
I like Dr. Sapolsky's lecturing method, it is dynamic and insightful.
It's interesting that most of the criticisms he mentions about the field are actually mentioned in Robert Plomin's 1990 book (and Plomin is probably *the* behaviour geneticist).
The field isn't about elevating genes or environment in determining individual behaviour (which is mostly ridiculous) but asking about genetic contributions to individual differences. In a population, what amount of variance in that trait covaries with allelic variation?
I literally obsessed myself within mathematics because that was the only thing I had ever been introduced to that made logical sense to me
I am leaning the same way. But I am also painfully aware that statistics is a heavily flawed concept. There is no winning. Perhaps truth will always both sides of a dice
@@4philipp yup, it's so interesting how two different people can "prove" something in opposite directions, both backed by statistics, and both can sound credible.
Watching the first part of this as a dichorionic identical twin was mind blowing
it's fantastic that we can enjoy this great teaching guy: Thank you, Mr. Sapolsky, for your wonderful work and teaching.
How do I get this guy to join my dinner party , it would be epic
I'd love to know too!
I'm willing to bet some very wealthy and powerful people have asked the same question at some point or another.
Maltese Falcon
There's a 'Dinner Party Request' form on his website. He's a picky eater though.
@@awhodothey what's his website called? I didn't see it on Robert Sapolsky rocks or Stanford
@@buttscooter420 he took that page down after Robert Downing Jr had to cancel his invitation due to the controversial primate psychology tweets Sapolsky made in 2007.
This is soo fascinating, Mr. Sapolsky explains everything perfectly and makes me just want to know more. Thanks for making this lessons open to access.
1:00:29 He means "Leningrad" (Currently St. Petersburg). Leningrad was under siege during World War II and the only way food was able to come into the city was in trucks on top of the ice which covered Ladoga lake in winter. This was a very dangerous endeavor as many trucks broke through the ice and drowned... Stalingrad (Currently Volgograd) was completely destroyed by German bombardment. It was Germans who were "under siege" or rather surrounded by the Red Army under Stalingrad, and faced starvation, but since they were mostly male and couldn't get pregnant - they don't matter as much to a Behavioral Biologist LOL OK I didn't really expect Sapolsky to know the World War II, The Eastern Front "bucket" ;-)
"Many trucks broke through the ice and drowned..." the trucks drowned? Ohh nooo, poor trucks :(
See, by the winter of '42, the whole city was surrounded by the massed Sixth Army. It was pressing and pressing. The Russians couldn't hold on much longer. Many wanted to submit. Those kids have no idea whatsoever of what went on at Stalingrad. Although I can in no way compare my struggle reading it with that of the Red Army, it has been a very big read.
I believe he meant trucks can't drown. To drown means to inhale water and die. Trucks can sink
@May Day Or maybe it's you who has something wrong with them, if you aren't able to understand what humor is.
@May Day 😂Are you miserable?
Understanding Behavior Genetics and Genetic Influence on Behavior
00:16Introduction to behavior genetics and evolutionary psychology
01:36Shift to molecular biology and support for punctuated equilibrium
05:02Challenges and approaches in behavior genetics
08:28
Genetic and Environmental Influences on Identical and Fraternal Twins
16:51
Gender Differences in Math Skills and Genetic Influence
25:16
Genetic and Environmental Factors in Schizophrenia
33:41
Comparison of Genetic and Prenatal Effects in Behavior Genetics
42:06
Influence of Prenatal Environment on Behavioral Traits
50:31
Impact of Prenatal Stress and Nutrition on Brain Development and Metabolism
58:54
The Impact of Prenatal Programming on Adult Health
1:07:19
Genetic Inheritance and Prenatal Effects
1:15:41
Inheritance of Traits and Behavior: The Influence of Transcription Factors and Indirect Genetic Effects
1:24:05
Inheritance of Non-Genetic Traits and Epigenetic Changes
1:32:28
The Impact of Neonatal Handling on Maternal Behavior and Genetic Expression
The video script discusses the impact of neonatal handling on maternal behavior and its effects on offspring's size, health, and intelligence in rats. It also explores the influence of prenatal environment on behavioral traits, genetic inheritance, and epigenetic changes with multi-generational consequences. The script highlights the complexity of genetic and environmental influences on behavior and traits, including the impact of stress and hormonal exposure during fetal development.
Understanding Behavior Genetics and Genetic Influence on Behavior
Introduction to behavior genetics and evolutionary psychology
Shift to molecular biology and support for punctuated equilibrium
Challenges and approaches in behavior genetics
Genetic and Environmental Influences on Identical and Fraternal Twins
Identical twins share more genes and environment, while fraternal twins share less genes and environment.
Behavioral traits in twins can be attributed to genetic influences and shared environment.
Differences in genetic and environmental influences can affect traits and behaviors in twins.
Gender Differences in Math Skills and Genetic Influence
Study showed significant difference in average IQ between girls and boys, with boys having higher IQ.
Boys also scored higher on math SATs, with a 13 to 1 ratio of boys to girls in highest math achievement.
Adoption studies and genetic influence on schizophrenia were explored by Seymour Ketty at Harvard.
Genetic and Environmental Factors in Schizophrenia
Adopted individuals more likely to share schizophrenia trait with biological parent than adoptive parent.
Study in Denmark showed a 9% incidence of schizophrenia in individuals with biological legacy of schizophrenia.
Adoptive studies on heritability of various traits showed strong genetic component.
Comparison of Genetic and Prenatal Effects in Behavior Genetics
Prenatal effects can be measured by the percentage of shared traits with biological parents.
Paternity uncertainty and non-random adoption placements complicate genetic studies.
Identical twins separated at birth provide a powerful approach for behavior genetics studies.
Comparison of monozygotic and dizygotic twins helps control for non-random adoption placements.
Influence of Prenatal Environment on Behavioral Traits
Behavioral traits can occur in the absence of learning or environmental experience.
Examples of universal motoric patterns shared among all humans, regardless of prenatal environment.
Prenatal environment, including hormonal exposure and maternal age, can influence later behavioral traits.
Impact of Prenatal Stress and Nutrition on Brain Development and Metabolism
Prenatal stress leads to smaller brain and thinner cortex in rats, affecting learning abilities and anxiety levels.
Stress during pregnancy can result in smaller brain region that regulates stress response, leading to elevated glucocorticoid levels.
Fetal exposure to starvation during Dutch hunger winter leads to metabolic programming, increasing risk of obesity and metabolic disorders in adulthood.
The Impact of Prenatal Programming on Adult Health
Prenatal programming occurs in the second to third trimester of fetal development.
Exposure to stress hormones during fetal life can lead to increased likelihood of anxiety disorders as an adult.
Prenatal exposure to estrogen derived from phytoestrogens may lead to a small but consistent increased risk of estrogen-dependent breast cancer later in life.
Fetuses can learn and remember sensory experiences from the prenatal environment, impacting their preferences after birth.
Genetic Inheritance and Prenatal Effects
Prenatal environment influences anxiety levels, not genetic traits.
Mitochondrial DNA is exclusively inherited from the mother, impacting genetic inheritance.
Transcription factors in the cytoplasm of eggs come from the mother, affecting gene expression.
Inheritance of Traits and Behavior: The Influence of Transcription Factors and Indirect Genetic Effects
Transcription factors from the mother and father have different significance in gene expression.
Environmental toxins can disrupt the activity of certain transcription factors, leading to non-genetic inheritance of traits.
Indirect genetic effects, such as physical traits, can influence behavior and personality.
Inheritance of Non-Genetic Traits and Epigenetic Changes
Inheritance of social rank is not based on dominance traits, but on genes related to feather color.
Newborn chicks' tendency to peck at their toes is a heritable trait, not the ability to find grubs.
Political party affiliation, ambiguity tolerance, and aggression have genetic and indirect genetic influences.
Epigenetic changes can lead to multi-generational inheritance of non-genetic traits.
Neonatal handling of rats can influence brain size and life expectancy across generations.
The Impact of Neonatal Handling on Maternal Behavior and Genetic Expression
Neonatal handling causes dramatic changes in maternal behavior based on rat handling.
Variation in rat mothering styles affects offspring's size, health, and intelligence.
Epigenetic changes caused by maternal behavior have multi-generational consequences.
I loved this lecture. I'd love to have him for a professor.
Love these lectures, 100p, as a dizygotic twin myself i can definitely confirm I grew up in a completely different environment than my twin, different primary school, different length of time spent w the rest of the family, more neglect etc
just wonder, How does this have an effect on you?especially the neglecting part
Not only an incredible lecture but a piece of ASMR-joy too :)
Make that obnoxious crinkling noise stop! I hope it’s gone in the next video
This guys is a great professor. This is my current ADHD obsession. Normally at this point I could have bailed out and found something else, but I can’t stop!!
I made it through the last 5 in the last few days.
After this i'll be looking at pregnancies differently. And I wonder if my mom was stressed or how much and what kind of food did she eat
Or it could have been the grandmother you need to look at. As a European, the war generation has a huge influence on us.
This should be required viewing for all pregnant mothers.
A lot of things should be. 😂
14:10 "those who could not afford to buy Armadillos". This guy is hilarious. Great series.
Amazing lectures! I'm realy grateful for the chance to learn about human beghavioral biology
The best ending since ''Luke, I am your father'' or how that quote went
I've watched these six lectures back to back and I have to say this guy is really cool.
how cool ? btw who is in your pic ?
omg he is fantastic! This is for myself personally the first time I have ever herd a person use a mathmatical approach towards actually proving how nature and nurture both play roles statistically towards a persons mental, and emotional health. I am sorry if i was not well spoken, or informed. This is just my opinion thus far.
status of understanding why a behavior emerges: it's complicated...
I love this so much. esp, rn, I need a teaching and learning scientific community. I love going over fundamental courses, esp when they evolve so rapidly. my current solace is bracing my base knowledge so I can go buck wild on the virology ❤ thank you
"What we are going to see next class is the proof that these las two hours were absolutely irrelevant" HAHAHA
Drink everytime someone coughs.
Maaaannn that was annoying.
it sounds like a social contagion, memetic. or perhaps the coughs form a Morse code commentary on the lecture.
I died
Ahhhh, good old Robert Sapolsky... the best professor/stand up comedian combo out there
Ahoj
These lectures make my life better
I go to community college and this by far has been greatly more educational than most classes I have attended =)
That’s why Stanford comes with a price tag, and is challenging to get into!
Science update: though most mitochondria come from the mother, the father does contribute some mitochondria to the embryo, so mitochondrial dna is only overwhelmingly matrilineal not completely.
Thank you. I just got to that part and couldn't believe that the Sperm simply contributed the amount announced.
So does the theory about mitochonrial eve still hold?
@@turbulence5691 Mostly. However we have learned there are exceptions to the rule that could change dates, rates, and how some haplotypes were inherited. They really don't have this new info assimilated into the big picture but our views have been rapidly shifting in molecular biology the whole time. Check this out.
www.the-scientist.com/news-opinion/fathers-can-pass-mitochondrial-dna-to-children-65165
@@HotPinkst17thanks for the article man, btw i found a couple articles still talking abt Mitochondrial Eve from 2020 (the discovery came at around 2018 i think)
www.thegreatcoursesdaily.com/mitochondrial-eve-the-mother-of-all-human-beings/
So I think for most practical purposes, they're maternal
Thanks for the update. I really wish they would do an updated version of this series, or maybe even just a video that explains all of the discoveries made since these videos were created.
he mentioned/accredited so many female scientists!!! i love these lectures so much
Sapolsky mentions the adoption studies carried out in my home country, Denmark, by Thomas Bouchard. These dealt with schizophrenia. He fails to mention adoption studies carried out by Teasdale and Owen, also in Denmark, and later referred to by Bouchard. These were about intelligence. They were studies of adopted-away full-siblings, half-siblings, and unrelated children. All were boys, born between 1938 and 1947. Then they got the draft board records of intelligence tests of these boys when they were young adults (I know these intelligence tests; i was born in 1949 and tried the same tests). The data treatment gave as a result a 0.04 percent influence of environment, and a staggering 0.96 percent heritability of intelligence test results - the highest ever obtained. Why would intelligence be genetically determined to such a vast extent exactly in Denmark?
The Danish society at that time was ethnically very uniform. Also, there had been a long period of social upward movement in the parent generation, so that everybody intelligent enough to rise socially, had done so. The intellectual environment was very uniform - very few children went to private schools. We all went to public schools, and the school system was the same everywhere. Nobody was very poor, and schools in relatively poor districts were no different form other schools. There was only one (public) television channel, so everybody saw the same programs in television. We all read the same Donald Duck magazines, etc. etc. The whole intellectual environment was extremely uniform. So how could there be any influence of environment on intelligence? Well, there was no influence, and practically all differences in intelligence were genetic.
This, of course, would not be true in societies with large social differences. For instance, an earlier study (around 1950) of attained level of education in Norway showed a large effect of environment - children from remote parts of the vast country did not have the same chance of a higher education as children from larger cities, even if they were intelligent. So there was not yet the extreme social mobility which later characterized all Scandinavian countries.
Now, why should Sapolsky have mentioned this? Because the students get the impression that intelligence is very much about environment, with the implications that differences in intelligence are unjust, some children getting better chances in life than others. But he Danish results indicate that you may eradicate all social injustice, and there will still remain large differences in intelligence, which cannot be removed in any way whatsoever. So even though part of the differences in intelligence in more socially stratified societies, like USA, may be ascribed to some sort of social injustice, the main point is that there will always remain large differences in intelligence which can never be removed, not matter what social engineering you may carry out.
@John There are aspects that are close to socialist ideas, but Denmark was and is not a socialist country.
Did they control for intelligence of the biological parents & household you grew up in? Even if society is uniform, parents aren't. If your household consists of more intelligent people, you learn more from them and can get better help with homework & co.
While I understand your point, there are too many aspects to be considered that aren't demonstrated to have been controlled for in your explanation of that study. Parents loading higher in different cognitive acuities, i.e. higher verbal intelligence, spatial-relational, etc, would have varying influences on their children. Personality of parents is another factor to be considered; more open parents versus more conscientious parents - children with parents who loaded higher in trait openness would perform better on most cognitive batteries (including creativity questionnaires) as these parents will be more likely to expose their children to more content of varying aspects. Temperamental variances explain for behavior and performance outcome better than IQ does. Loading higher in trait Conscientiousness has a strong correlation with performance (for example: fiscal success, grades) and very high levels of trait Openness has a negative correlation to grades but positive correlation with fiscal success. IQ can't be changed significantly by environment (no jumps in 10+ points, that hasn't been shown, but variations of up to 2 to 5 points have been) The environment will have a notable affect on the individual (diet, sleep quality...). But you can't transform someone with an IQ of 90 to someone with an IQ of 140.
@Bumblesnuff buffallobath The Rise of China directly contradicts the environmental hypothesis. China suffered Revolution Warlords, Invasion, Civil War, Invasion again, Mao, Famine, closure of universities and as soon as they adopted market economics, (and then not even fully ) they began developing. Why can't Mozambique do this? Why not Senegal? The Congo? Peru? Laos? Easy: they're dumb.
Same for South Korea: war leveled every city in the country, then military dictatorship until 1990. Both countries developed because the people are smart. We have data from China 1986-87: their IQ was 99.7. Not even a generation after Mao and they were as smart as Western Europeans, even tho their environments were far poorer.
Twin and adoption studies today show parenting doesn't matter. ENvironmental hypotheses fail to predict anything. Genetics does.
@@mykah3317 Yes.....5 to 10 points on IQ are negligible. In the 60s and70s we tried to develop culture Free IQ tests in hopes that certain populations would then score much higher than on the Weschler or Stanford Binet...scores were not higher in the populations when those tests were used. Then we spent decades trying to social engineer smarter school children through Head Start programs...millions upon millions of dollars spent high amounts of energy spent on follow up studies were we able to raise IQ and also academic achievement but enhancing environment.nooooo. THere was a SMALL positive effect for two years five years later the effect was gone. Huge energy spent because se oh so WANTED a,different outcome.
“Boys in the Johns Hopkins Center for Talented Youth Program had higher math aptitude and were vastly overrepresented at the highest echelons of scores”
I remember going to that program myself, another problem with this study is that using those scores is NOT anything even remotely resembling a randomized sample, it’s kids with very rich parents who were normally selected at an early age for “gifted” programs.
(50:00)
When the fetus is exposed to stress hormones (mother is stressed) it can cause the brain to be smaller- especially the part which turnes off the stress response
- more prone to anxiety
- problems with learning
Another issue is that most non-hearing people are not completely deaf. They can hear their own voice. They can hear loud low frequency sounds such as music, explosions, etc. truly deaf people, who have no perception of sound whatsoever are fairly rare.
He is the Bob Ross of behavioural psychology
These lectures are qmazing. Thank, you, Stanford University, for uploading them for us. Dr Sapoksky is a very special kind of lecturer.
If course, I'd only expect the highest standards from Stanford. In around 2007 I downloaded a series of lectures on the Historical Jesus by a Professor Sheehan of Stanford. They were the most interesting set of talks and also of the highest quality.
It is interesting how he points out a whole field, behavior genetics, relies on some pretty dubious assumptions for their research.
This is only lecture 5...the understanding evolves through the 25
Science evolves. We have to remember that each discovery was groundbreaking at the time. The more data is available the more nuanced the research can continue
Still the best lecturer in his field of humanity sciences. Total respect 🙌
Love this guy, but that coughing is driving me crazy!
Professorapsky is a great speaker I can hear every single word
So incredibly interesting, I kept having memory flashbacks of several animal baby cases that I have experienced. I have seen good and bad cow moms, good and bad cat moms, I've had abandoned calves and kittens being hand reared, I've had adoptees of kittens and heard of adoptees of calves which I hope to witness sometime. I have had calves stay with mothers but be support fed by bottle in the first 2 weeks because of nursing issues so they were handled as young but not later. I've had newborn calves imprint on me as I saved their life over the span of several hours, I have seen calves where they lost the mother before weaning age, I have also seen calves stay with mom too long as well seen lots of twins, I've seen the passing down of stress sensitivity... it goes on and on and I remember so many effects on developing personality from all these situations. I keep my eyes on differences and it interests me deeply!
A behavior like whomever is clicking their pen neurotically while recording this. But I digress, just happy to be given these sit ins in the first place. Namastay
I'm so grateful for this . Thank you professor.
His collection of lectures is responsible for millions of us who didn't go to college, to go to college, at least for this series. Does anyone have the list of books that he mentioned for each assignment?
I love this series!
Very, very enjoyable. Love Dr. Sapolsky.
I am loving this class.
I'm viewing these in order. This is my favorite so far. I am so beyond fascinated. I would love a chance to have a conversation with this guy.
Bookmark: 58:06 (Dutch Hunger Winter)
More ones, more ones? Ok, that was good grammar. More ones.
Haha, love this dude. I'm totally amazed by his way of explaining the complex studies in a playful manner.
It’s only possible because he knows so much more then what he teaches.
What an amazing lecture !
soo complicated but so interesting thank God for Dr. Sapolsky
I'd love to hear a discussion / debate between him and Bruce Lipton
The Jesus yesss