3. Behavioral Evolution II 

Netflix doesn't even have anything as binge-worthy as this guy's videos.

"Can't afford college but can't afford ignorance either" Comment on lecture 1 of this series. Thank you Stanford. This is priceless. And Sapolsky's conversational and apparently free flowing style is insanely engaging!!

I'm amazed how he doesn't stop to think what he's saying. He's so versed in the matter, all these matters, that he just flows through it. It's amazing and awe inspiring.

I’m so unbelievably happy to be part of a generation where you can learn about anything and everything, basically for free, at this high of a level. It is a beautiful thing to share these things, and for a prestigious university as Stanford to give it out for free, that’s just amazing. Thank you!

Man Im really stressing about this midterm

00:42:44 Imprinted Genes 01:16:17 Criticisms 01:20:34 Adaptationist Fallacy 01:30:21 Punctuated Equilibrium 01:32:11 Political Critiques

Getting to this third lecture I'm realizing part of the appeal of this prof is how effectively he communicates. He delivers information efficiently (hardly wastes any spoken words) while not being dry, and without constantly checking notes, it's very impressive.

Some good news: in the decade since this video, the population of mountain gorillas has increased. It's still tiny (over a thousand gorillas) but they're still around.

I am so grateful he provides a critique to end the lecture. Whenever I learn bout something and it seems really convincing and mind-blowing, I always immediately look for the a critique of what I just absorbed, otherwise you run the risk of getting carried away with one perspective instead of weighing the points of multiple perspectives.

Sapolsky is the greatest lecturer I have ever seen. I am not a student of human behaviour but this guy makes me want to change the subject what I study! I read comments about his style being more teenager-like and less "professional", but what I see is a highly intellectual person engaging students with "student-like" speech. Obviously, he could give a lecture with more professional terms and without humour, but that at the end of the lecture, you would sit there thinking the same like after every lecture. "There is this guy, talking like a non-human and expects me to understand everything." We need more people like him who instead of trying to push down 100% of the facts on students throat focuses on engaging the audience with funny, easily understandable language and 98% of the facts. My personal opinion, that 2% loss of facts worth the exchange. This is my subjective opinion, but considering that during his videos I am not able to stop it for a second and constantly laughing and being amazed by all these things, his style is so human that is indescribable. I wish I had teachers like him from 1st grade...

"Many hands make the itch less scratchy." - Robert Sapolsky Brilliant!

"the males fall for it" is my new reply to people when they start questioning my knowledge

I'm surprised that this is free and very grateful they are. Thank you Stanford University :)

It's truly stunning that he can go through an entire lecture without once hesitating or saying erm.

The fact that there is so much positivity , creativity and thurst for knowledge in these comment sections makes me hopefull for the future of humanity.

This happened a decade ago and this information is still so damn relevant and he is so well spoken. It induces genuine interest and attention.

whoever said "Man is the only creature that kills for pleasure." must have never had an indoor cat.

Aaaaah...lectures without homework. Doesn't get any better than this :) *sits back in cheap plastic chair*

I'm very grateful to both Stanford and Dr. Sapolsky for making this publicly available. Dr. Sapolsky's lecture style is amazing. I'm hooked! Kudos!

His calm demeanor is so comforting in the academic field

The information in these lectures is fascinating, but I'm equally impressed by Sapolsky's ability as a lecturer. I haven't had a biology course (or many science courses at all) since I was in my mid teens, and he still manages to make all this information totally digestible. I don't know if his writing style is similar, but I'll definitely look into buying some of his books.

Dude, those last 10 minutes were intense.

I'm a brazilian with access to Stanford university lectures, I feel privileged.

These lectures are addicting. No feeling matches the power you feel when you're armed with new knowledge!

I am appalled on how many subtle and amazing jokes and irony this man made that were not caught by the audience, in part 1 and 2 as well. All in all, this is amazing , I would have sold my soul to have such a teacher in my Uni years. He is one of a kind. Presence, discourse, likability, and of course out of this world knowledge.

How could you possibly take notes in a class like this? This guy is just an endless stream of interesting knowledge.

Lecture Three Notes 1 Hour 36 Minutes 58 Seconds Link to other lectures of the series: ru-vid.com/group/PL8DarU8p0CpeH0FZwIdq6jiMXAa_dsb1E Minutes 1-10: - The professor discusses what will be on the midterm/final and states the specific chapters and passages that need to be read are specified on the handout that was passed out in the last class. - Next the professor reviews the major points of the last lecture. The major point being inevitable logic and how it is based off the building blocks of individual selection, kin selection and cooperative altruism. - The professor then notes the patterns of inevitable logic that have been identified in tournament and pair bonding species (and continues to do so for the first sixty minutes of class) 7:55 Minutes 11-20: - The professor reports that the work done on Lauinger monkeys by Sara Hrdy in the 1970’s identified that humans are not the only species to kill or commit infanticide. Infanticide is the killing of an infant before its first year of life is fulfilled. The professor clarifies that these murders have a pattern. - The professor specifies patterns are that the murderers tend to be males and the prey murdered by the males are most often children of other males and that these murders are committed in an attempt to enhance their chances to pass on their genes. Therefore, these animals were working from the standpoint of individual selection. A few animals that follow these patterns are mountain gorillas, lions, and various species of monkeys (such as Langer monkeys, Vervet monkeys and Pygmy monkeys) - The professor then gives additional examples of how other species (horses 19:18 and rodents 19:37) practice infanticide. Minutes 21-30: - The professor gives additional examples of how varies species practice inevitable logic and its building blocks. Langer Monkeys 22:20 and Savannah Baboons 26:50. Minutes 31-40: - The professor discusses sex ratio fluctuations as it pertains to individual selection and social context 31:36 The example the professor provides primarily states that having a daughter is a Conservative Strategy because a daughter is less calorically taxing. Thus, females are born in times of high vulnerability. Having a male is physically more taxing which typically results in only high-ranking species taking the hit to produce a male because it is not a Conservative Strategy it is a Risky Strategy. - The professor discusses role of kinship amongst various species and how polyandry and adelphic polyandry may be present in these roles. 36:50 (The specific example given is in lion prides and humans. When there are two male leaders of a lion’s pride it is usually adelphic polyamory. That is the two leaders are brother’s aka adelphic polyamory. In humans this can be seen when one woman marries a multitude of brothers. Adelphic polyandry amongst humans usually occurs in agriculturally impoverished areas. The logic of why humans and lions practice adelphic polyandry are the same. The logic is kin selection. It is to increase the chances of passing down genetic coding.) Minutes 41-50: - The professor briefly discusses intersexual competition as it pertains to individual selection 41:53 - The professor discusses imprinted genes (a concept developed in the 1990’s) and reproductive strategies of imprinted genetic mechanisms regarding individual selection 43:09 (Methylation is the genetic mechanism that causes imprinted genes. In simpler terms Methylation is what makes genes work differently ergo imprinted genes. Imprinted genes work differently depending on which parent they come from. Imprinted genes from males usually are all genes that enhance fetal growth by making receptors more sensitive to insulin like growth factor. Imprinted genes that come from females are all usually genes that slow down genes that decrease fetal growth by making receptors less likely to find insulin like growth factor.) - The professor highlights that a lot of the of imprinted genetic mechanisms used between partners are destructive to the reproductive longevity of the females in that partnership. 47:45 Minutes 51-60: - The professor clarifies you do not find imprinted genes in pair bonding species. Imprinted genes are found in tournament species and those that fall in a category of a hybrid between tournament and pair bonding species aka humans. - The professor addresses research done by William Rice of Santa Cruz on the sperm competition amongst flies. Sperm of certain flies kill sperms of other males. However, the toxins of the sperm are also toxic to the female flies in which they are ejaculating in. House flies are not a pair bonding species so this makes sense from an investable logic point of view. 52:22 - The professors introduce the concept of an animal leaving its initial community at puberty. Specifically, he discusses how in the chimp species females leave and in baboons males disperse at puberty. Therefor the males of chimp groups are all brothers and the females of baboons are all sisters. - The professor then asks, based on this information which species have more male on male aggression, chimps, or baboons? The answer is Baboons. The next question is which species have more advanced and productive war patterns. The answer is chimps. This is because there is more kinship in chimps than baboons. 56:05 Minutes 61-70: - So the professor spent the first sixty minutes of class discussing different scenarios in which the building block of inevitable logic comes into play, now, the professor attests that group selection (behaving for the good of the group) also comes into play within the world of inevitable logic but only under a few circumstances. Those circumstances include the Founder Effect and a more Generalized Founder Effect - The professor begins to discuss the Founder Affect. 1:00:32 The Founder Effect= Something happens that isolates a small subset of a population. The sections go about reproducing and the population with less people will be more inbred. Levels of corporation will be higher in the group with more inbred occurrence. So, there is a high level of corporation due to kin selection. The high productivity of the small subset of people develops is so advantages that that behavior turns into an adaptable gene which enters the major population. To put it simply, the mass productivity amongst the inbred founder population drives larger populations to cooperative altruism in order to try to become equally if not more so productive. - The professor then begins to discuss A Second Scenario in which group selection can come into play. 1:07:44 Generalized Founder Effect = You have got chickens with an array of traits one aggressive chicken lays a lot of eggs and one pacific chicken lays little eggs. The aggressive chicken lays a lot of eggs that produce babies and the passive chickens do not. This results in a lot of aggressive chickens that attack each other. This leads to low fertility rates amongst the aggressive subset of chickens. So now we are in this very important world where figuratively “group A can dominate group B but where groups of B will dominate groups of A.” So the group of aggressive chickens could together take out the pacific chickens, bust individually isolated from the other group the aggressive group of chickens (group A) would likely kill each other off leaving the passive group of chickens alive and ready to pass on their genes. Minutes 71-80: - The professor addresses the work of David Sloan Wilson “Darwin’s Cathedral” where he analyzes clusters of new religion over time and highlights how they are based in the found effect, group selection like properties and inbred cooperative strategies. - The professor begins to discuss Multi-Level Selection 1:11:09 Multi-Level Selection = Sometime selection is entirely dependent on one gene. - The professor moves on to discuss that when predicting behavior remember that social behavior is dictated by acting in whatever way one must in order to maximize the potential in passing down there gene which may be thwarted by kin selection and then by cooperative altruism and at times (but rarely group selection). - The professor then goes about addressing the popular criticisms given to the tenants he just stated/listed above. The criticisms negating the primary tenants of inevitable logic which are as follows: heritability, adaptiveness, and gradualism. Minutes 81-90: - The professor addresses the criticism against heritability 1:20:08 - The professor addresses the criticism against adaptiveness and discusses adaptative fallacy 1:20:35 The professor addresses the criticism of adaptiveness by Steven Jay Gould (Harvard Paleontologist) and Richard Luyeton (Harvard molecular geneticist). The two Harvard men said that behavior did not adapt because of adaptiveness but because they are spandrels. Spandrels are the unavoidable spaces between arches. So, the two Harvard men were essentially saying that some developed behavior has no explanation, it is just there. - The professor addresses the criticism against gradualism 1:30: 22 Minutes 91-106: - The professor addresses punctuated equilibrium. 1:31:08 Punctuated Equilibrium = The argument that there can be moments of stagnancy followed by great change with no gradual nature present aka “the hypothesis that evolutionary development is marked by isolated episodes of rapid speciation between long periods of little or no change.” - The professor clarifies who the harshest critics of this theory really are 1:33:38 - The professor clarifies that although there are a lot of hot takes on why inevitable logic is wrong the most popular criticism is that is justifies immoral behavior.

This is the best thing about Internet , knowledge seekers like us will be forever grateful to Standford and Professor. You have no idea how you r changing the lives of people across globe. Love from India🙏

Wow, I only looked him up because I purchased his new book and since I can't get enough of him..I love his interdisciplinary critical realist approach. Thanks ever so much for sharing his amazing lectures.

Jesus, my French final is tmrw and haven't started reviewing in because I have been binge watching this, I can't put this down

His beard has its own class at harvard advanced beardonomics

This is absolutely fascinating. Putting this on youtube makes the world a better place, thank you.

I just finished the third lecture in 3 days, understood every single point, I have taken soo many notes, learnt them by heart, whats amazing is that i am going to finish all lectures and hopefully understand everything- what a privilege it is to have these videos, sapolski is a legend

"Whoa, what a guy!"

It’s incredible that I, an Indiana core maker, can learn about behavioral evolution from a Stanford professor all while I work. This is truly the Information age.

Came for the knowledge, stayed for the B E A R D

The lecture starts @3:14

if you are binging this, he stops summarising last lecture at 11:57

"Calvin and his sidekick Hobbs..." I very much appreciate how seamlessly the small little winks are woven into these already very interesting and entertaining lectures!!!

Thank you so much Stanford University for this amazing opportunity, and prof. Sapolsky for making such an enjoyable lecture series.

This is the BEST Professor on RU-vid because of his brilliance, humor and knowledge. Human Behavior is mostly ignored in all societies. Is it not?

This is the most interesting lecture I've had in years thanks Stanford for sharing this, much obliged

I feel so privealged to watch this for free. He's an amazing lecturer and what I appreciate most is how fluid he's explaining such a complex subject in a digestible way. Incredible!

Nothing like getting back from a hard day at school and watching school

I'm studying human behavioral biology at Stanford

this was recommenced for me for quite some time and corona made me watch it. omg. I am a master student and I have seen good lectures, by all means. Specially in the masters, professors are super excited to share their knowledge (not just the boring basics) and are soo into it. but even compared to the professors who I adore and love and learned so much from, Mr Prof Sapolsky is taking to another level! Thanks so much, Standord!

18:02 Glad to say that there are currently 1000 estimated mountain gorillas in the wild today, as of december 202O. Go conservation!

1:14:07 : I wish Jordan Peterson would've taken this class before writing about how about lobster society determines our hierarchical structures

Such a great professor. I could just listen to him all day.

This lectures are gold. His teaching is so incredible - almost like narrating a story.

Second time listening to the whole playlist, now doing it while coding, so that I can feel smart by proxy while being dumb at my job XD

I wish they hadn't cut the ending off so abruptly :(

Form and content at their best in the classroom. My interest in biology is near nil and I always hated behavioural studies. But this is quite a different level of teaching and I cannot get enough of this lecture series. my alternative was watching the next episode of the crown but this guy here is even more fascinating.

This is 10 years old and I have looked forward to this video all week. Hope you are well, Professor Sapolsky.

I have listened yesterday the 1st part, today I have scheduled this 2nd one. Congratulations. I have learned so much on these classes and the style of speech, and keeping the audience focused by many small jokes. Sincerely, MD dr. Dávid Cs. L.

Wow!! This guy is a TERRIFIC lecturer!! He knows his stuff so well that he can just stand and deliver without any notes at all and without even pausing for breath!! Fascinating subject. Thank you to Stanford U.

Why keep stopping these videos in the middle of his sentences?

I love how well thought out and balanced his lectures are. He presents a logical idea and then disembodies it with the opposing critique. This emphasizes the notion that he brought up earlier that behavior is enormously complex and cannot be explained by single phenomena. This principle branches out to so many human behaviors...racism, generalizations, preconceived notions, judgement of others, etc that plague our society. These are all factors of what I consider primitive cause-and-effect, correlation without causation brands of human thinking and not taking into account that the individual is not capable of such deductive thinking based off the information at hand.

I love how he always brings in National geographics to the discussion XD

I love listening to Sapolsky. First saw him in a documentary, 'Stress, Portrait of a Killer', and then came across these lectures. I am not in the field but have always had a fascination with watching and analyzing animal behavior. I have been listening to these while working and am going to read the books he suggests. Hmm...maybe I should go back to school...

not me actually failling my exams but going through 3lectures of human behaviourial biology in a row and loving it

The last 5 mins were at least mind boggling. Thanks for the free lectures Stanford!

Can I just watch these kinds of videos for a living

Watching this series through for the second time. :) Just as enjoyable as the first time. I'm so happy that these lectures are available online.

ON SAPOLSKY'S VERY SPECIAL SPEAKING STYLE - 790 words, April 23d, 2022 What impresses most listeners first about Sapolsky, even more than his messianic beard, is his passionate speaking style, like a speeding locomotive rushing towards some goal. This is never small talk, but an interrupted flow of statements, citations of facts, constantly referring to what he calls “the literature”, the sum of published papers in the scentific journals related to his topic. He sounds as if he never pauses to catch his breath, even though he does, quite imperceptibly, and does not seem to need to prepare in his mind his next sentence (unlike for instance Obama). This continuous flow of speech is mind-boggling. He is not acting as if he were following a set text that had become intimately mastered for having been repeated year after year. His method is a bit freer. He just needs to grab a key word, a concept, a fact, and that single lead is enough to set him off into a non-stop discussion of the point for as long as he has time. And those lead concepts are all spelled out in the notes spread in front of him on the desk. He needs a simple glance from afar to end the current point with a resonant "OK" and launch the new segment. He knows the whole extent of each point, and all the related tangents, so well that he can freely let his mind navigate in multiple directions and tangents in that vast territory without losing the thread of his destination and without having to control or edit what comes next. A few times, he realizes he is drifting too far afield, catches himself, and switches directions. But this self-correction is nearly instantaneous, a second or two. He is more like a geyser, or a torrent, than a river. His speech is not so much a flow as a continuous eruption, with many branches that all return to the point.. And I think there’s more to it than just being thoroughly familiar with his subject, or even an ease due to repeating the same points year after year. Beyond knowledge and memory, I suspect there’s a neural engine in his brain that sets his speech into motion with enough energy to go on for one or two hours without taking a break. And this engine does not start in first gear, but in fourth. The source of this energy is a personal neurological trait distinct from memory. Watch Barack Obama, who also knows his subject very well, and rehashes the same points of his intellectual life over and over during his public career. However, at the opposite of Sapolsky, Obama mentions a fact, an idea, and then stops, letting it sink, while surveying his audience to judge if they are imbibing his words, and appreciate their weight. It is not that Obama is hesitating, not at all. Like Sapolsky, Obama knows very well what target he is aiming at, but he takes his time. The mountain is there and he knows exactly how to climb it, and all the ways that get to the summit. But he is not in a hurry to speed towards his goal. Whereas Sapolky is driven by his inner engine to rush forward at full speed, as if subject to a mental force that keeps accelerating his output. This is an unstoppably driving engine that Obama does not have, and does not need. I have watched Sapolsky’s 25 lectures of this Stanford Un. course twice, with some lectures more than twice. I have also watched most of the seminars given to the public and posted on RU-vid, and some more than once. The same mental engine is at work in every one of his oral deliveries. At some point when he was starting to adib on his subject, he murmured to himself, “I’ll stop now because I feel a coming”, that is, he is feeling his engine continuing to spin on its own, and is concerned about getting carried by this engine too far, too long considering the time allotted to his presentation . At some point I’ll come across that moment again and will note exactly the word he used. All this to say that Sapolsky’s very idiosyncratic style is not just due to his intimate knowledge of his subject, which he has mastered without any doubt like any expert does, but to a special, personal brain trait which I compare here to a kind of spontaneous speeding engine that just needs to be jump started. Sapolsky must know the neurobiological description of his own trait and which parts of the brain are involved. This should be the object of a special investigation: What is the neurobiology of Sapolsky's own brain?

Stumbled on this by accident and was about to move on, but couldn't. I became transfixed with the content, and by his tone and delivery. Excellent, relevant, very interesting. Thanks for this. I'm going to go back and watch the videos leading up to this one.

Sapolsky is such a fantastic teacher and lecturer. I am hooked. I have not ever found anything so fascinating and completely agree with other comments that Netflix has nothing as binge-worthy. Thanks Dr Sapolsky and Stanford for making this available to all.

Wow, what a great man and professor, what a detailed info on what to focus on regarding exams. This is how university should be, educative, inspiring, encouraging studying and evolutionary thinking. Deeply grateful for this lecture!

I wish all lecturers made thier stuff available so anyone has access to Learning.

another comment in the first part of this lecture said this is binge-able and they’re so right. he even has the call backs to things that came up before, the foreshadowing to things that’ll come up later, and the amazing cliffhanger at the end of an episode that makes you want to go straight in to the lecture. amazing

I recently had an eye surgery, so I cannot even look at the screen, and yet could not resist listening to your lecture, Thank you.

During the last ten minutes, I have been thinking of the sociopolitical implications of the lecture. Dr. Sapolsky did not disappoint.

I'm so happy that these got posted. I love learning about stuff like this!!

This year I’m taking lecture courses at Stanford and Yale. Life is good.

I am a 72 yo. I find this subject fascinating . Makes a lot of sense. I just downloaded his book Behave which was written maybe 5+ years after this lecture series. I am looking forward to the new discoveries and his analysis.

I like this professor a lot! His communication style is exemplary!

Holy Bill Waterson,nobody in that class got the Calvin and Hobbes joke!

It's rare that someone who knows so much is also so good at explaining what they know so well to others. I started watching this 2 weeks ago and have now watched perhaps 30 hours.

You can tell how well he understands the material by how simply he explains it. Great mind.

Some humans are natural born teachers....Sapolsky is one of those human beings.

another great lecture as a whole -- esp everything from 1:13:00 onwards is insanely packed with deep knowledge and insight. great stuff

I plan to watch all his lectures on RU-vid. Sapolsky makes the subject matter interesting and easy to understand.

I grew up on PBS and Marlon Perkins . I brought home a dozen books from the library every week when I was young but if I had the internet and Stanford lectures and all of the education available for free when I was young ,, I would have ate this up, played repeatedly until I could quote it paragraph by paragraph until I understood every bit and who knows where I might have gone . I hope that there are kids today actually studying and gaining knowledge and not just taking selfies & tik toks and planning their LOOK AT ME life plans.

Every evolution biologist should have a Darwin beard.

my god, i'm tempted to skip out on my own classes so i can binge this

As someone who never had the opportunity to obtain a college education, specially of this magnitude! I am extremely grateful for this RU-vid channel! This professor is amazing! Thank you!

This is one gem that deserves millions of views man, thanks for uploading this

Thank you for making these lectures accessible to the public. My son and I are learning quite a bit from them.

i paused so many times just to let it all fall in to place.and I’m still pausing

I like how his lectures get Dark and sexual mixed wity humor and rationally.. as an instructor , he is a Master teacher! Keeping you intrigued while giving so much knowledge in such little time.. amazing

You're the coolest animal I've ever met professor

1:27:00 There was a theory where the size of the Kiwi's eggs were a spandrel. For those who don't know, kiwi's eggs are the biggest in terms of relative body ratio with mother. If you look at the egg inside a kiwi, it is so hard to imagine all the other vital organs fitting there. (About 20% to 25% of the mother body weight). Some might argue that the explanation for these enormous eggs were a family heritage. The family of kiwi is the same as ostriches, Emu, Ema, etc.. so, maybe, they "shrank" to be more adaptable for their Island environment, and maybe the egg is more of a heritage than an adaptation . Of course, there are some advantages, like how developed the newborn is. But is so much investment for breeding, it becomes really problematic when you are trying to repopulate a species to take them out of risk of extinction.

Hi, I hope someone read this comment, it will be usefull to organize the information. You guys could have on the video description like those links with the time so when you click you go back to the video part of it, each one dividing whenever the teacher changes the subject or part of the subject, maybe even the teacher can tell you the time... idk... Just because they are big videos ( big timeline ) and its really hard to find the right spot if you missed a subject or a part of a subject. Please thumbs this if you think it would help so can see the comment. Always and always GREAT content, we need to make the world a better place, lets live peacefully and positively. Thanks for such great videos!

This is gold. Pure gold. Can't express my gratitude. This is better and more entertaining than any documentary.

It is my duty to thank Stanford and this magnificent guy Robert Sapolsky these incredibly good lectures. Thank you very much.

1:05:48 I listened to this and I suddenly understood that he's talking about "familism", "amoral familism" (which is typical of Italian Mafia families) and "corruption". All these concepts have "reciprocal altruism" in them (beyond good or bad meaning).

Thanks for uploading and making all these priceless lectures available for all of us to see, I'm watching them from Mogadishu, Somalia..

I feel like this whole lecture can be called “life, uh, finds a way.”

This guy is such an awesome speaker, he’s knowledgeable and has a good sense of humour, makes difficult topics super simple

I'm really enjoying. This makes you rethink everything. History, culture, emotions, languages... System thinking rules.