 Alright, how am I going to get started? I've got a good number of slides. So, welcome, everyone, to this last talk of the Science Circle presentation season. I'm honored to be able to talk again and to, again, continue this dialogue about thinking of Darwin's evolutionary theory updated with all the modern research and modern thought that goes behind it. So, again, talking about the role of sexual selection, and just to remind you, I'm Stephen Gager. I used to be a college instructor and now doing research in the private sector. So, like my updating Darwin part one, I'm going to use as a scaffold for this talk another really well done and entertaining documentary called the Science of Sex Appeal. This was aired and I think produced by Discovery Channel back in 2009. And it does just two things really well in terms of science documentaries. One, it actually takes you through the experimental design and conclusions. And I think for documentaries where a lot of science is telling you what we know from the science. They don't necessarily take you through how the science was done and I think they did this really well. And two, it's actually really entertaining. So, even though there's a lot of science that is covered here, they do these little intermingled vignettes that are couples talking about their relationships related to the science. And so, anybody here who's seen, when hearing that sally, that is a wonderful little part of that that they kind of throw in here in that same type of idea. So, but of course what I do is try and give you a little bit more and some background and some perspective from a scientist as compared to just say watching it straight through on the TV. Which again, I do recommend you watch it. It's available as far as I can tell really only on Amazon and you have to purchase it. They used to be on Netflix, but it's not there anymore. All right, so just as a reminder and a backdrop talking about Darwin's theory of evolution is that there's this selective process in which there is variation among organisms and species. And again, individuals and species have this capacity to reproduce. And then there's selective pressures, things that cause some individuals to be more successful at reproducing. Either in most cases due to death, but in other cases due to say competition. And those that in general over time, those with the best genes passes on to their offspring. And again, it's very easy to figure this out. The ones that are the best hunters, the ones that are the strongest, the ones that are the fastest or have the best eyesight. These are all things that make very physical sense for how this works. But I just remind you that things like disease resistance is also a very important factor in survival of you and passing on your genes. Now, the strength of evolution in one of the driving forces, and this is illustrated by Darwin's finches from the Galapagos Islands, is that in order to really be able to take advantage of more resources and not compete as much against other individuals within a species, as individuals diversify. And this is an example where beak size, strength, shape can allow some finches to take advantage of different food resources. And so, again, the large ground finch, which is, say, one species, if individuals within that that ground finch started eating cactus or other men started eating buds or other men started eating insects, then there's less competition for food. And this is one of these things that can drive species into evolving separately. Again, accumulating traits that allow them to survive, but it's actually something that is diversifying individuals. Now, and this is, there's a concept here known as niche overlap, and that is how much competition you have for resources between two species and how good your computer species determines survival. Now, one of the areas, though, where niche overlap, this concept is 100%, where there's the most competition, is actually within the species. And this is a concept that Darwin, and again, a lot of people, historians of science credit Darwin as really coming up with some very smart lateral thinking to even come up with this idea, is that, I'll just quote here, when the males and females of any animal have the same general habits of life, but different structure, color, or ornaments, such differences have been mainly caused by sexual selection. That is, individual males have had, in successive generations, some slight advantage over other males in their weapons, means of defense, or charms, and have transmitted these advantages to their male offspring. And again, how does this fit into evolution? And of course, it is that the result is not death to the unsuccessful competitor, but few or no offspring. So again, he proposed this idea that competition within a species for mates is very important for determining the evolution and progress of a species. Now, I do want to say that this concept has been built upon and found numerous examples in the animal world so that it is not in any way disputed. This is something that there are wonderful model organisms showing this, showing how, for example, the peacock tail is an example of sexual selection, the lion's mane behavioral mating habits. And if you remember my last talk, we talked about the fruit fly, which has this mating dance in order to attract a mate. So, but I think, again, to make this a little more entertaining in terms of science dialogue, we're going to talk about humans. And what of course has really allowed humans to be a great model organism for this are a lot of new technologies. And you'll see some of these mentioned during the, during my talk if you watch the documentary. They're taking saliva swaps. This is a way of measuring hormone levels, basically sequencing DNAs, so you know what gene somebody has. There's this, computers are a great thing. They can do this eye tracking and also basically creating figurines and models of movements and shapes. And Photoshop, again, one of the best ways that we can alter perceptions of reality and change reality to what we want. And then brain scans, neurophysiology. You can actually see what the brain is doing in real time. It's just this amazing thing as you provide different things. And of course, we'll talk a little about chemical isolation and air delivery for certain things. And so, you know, Susan asks, you know, what this means to defense or charm as advantages? Where is the problem solving ability in that? Again, he's just mentioning some examples. And of course, intelligence and the ability to interact with the environment, hunt prey. There are any number of things that we can talk about as advantages. But I just want to be clear that for today's talk, we're going to focus on sexual selection. We can come back to it at the end. Okay, well, like, okay, so if I was talking about, you know, learned behavior, and again, one thing I want to keep in print here is that learned behavior is still determined by the genetics of the ability to learn behaviors or the ability to incorporate information from your environment and turn that into action. So in the way there is this nurture, but there is still a genetic basis for how well one can interact and be nurtured. Okay, so another little basic reminder of some physiology in humans. And what you see here on the left is the pelvis of a male. And on the right, the pelvis of a female. And the important thing being highlighted here is that the female pelvis needs to be in essence wider and also able to accommodate in a more circular fashion the passage of another human being's head from inside to outside the body. And again, that circumference or that diameter is typically in the range of 10 centimeters. And so the ability to actually also have this elasticity in the pelvis and all of the musculature that helps push any human head out of a body are all very important aspects that are, again, physiologically different between men and women. And this is an important thing I want to point out. There's a term here called sexual dimorphism. And so sexual dimorphism is when males and females of a sexually reproducing species have different physiology. And this is one way which is here. And just also another key reminder that I have here at the bottom is that in homosapiens and males, the burden of reproduction is much higher females in so many ways. And if you guys want to throw in a local chat some examples of that, I'll start it off by saying, hey, nine months of carrying around an extra amount of weight inside the body is one. Anybody want to put in their two cents? How about, you know, production of milk, lactation, glands for breast, and then also breastfeeding for, you know, one to two years? And there are things that they get sacrificed during that period of time. Again, these all are things happening to do with ramping up and changing the physiology of the body to support, again, another life. So the key thing here also to remind you that is that while there's a lot of investment by the female for having a child, there's also kind of, there's also a reasonable development in many types of species of pair bonding where the male staying around to help raise a child is actually also an important aspect that develops in some species, although not necessarily all of them. So that's something to keep in mind, especially with humans. Okay, so one of the other dimorphisms in the females is the menstrual cycle. And what this is, is a preparing of the uterus in order to be able to bear an offspring, to be able to nurture and support it, that occurs on a cyclical major that has nothing to do with the phases of the movement. And then if the implantation and pregnancy does not commence as not successful, then it basically sheds and restarts. Now, one of the key things, and this relates a lot to how we understand biology from this documentary, is that we can measure where women are in the menstrual cycle by measuring their hormone levels. And so this diagram shows in estrogen, follicle-stimulating hormone, glutamate-stimulating hormone, progesterone, these are all things that can be measured. So we actually know this. And what's really important about this, is that we think about successful reproduction and mating, is that there's really a span of about four days in which copulation with the male can lead to successful offspring. So there's this very narrow time. And one thing, or one way that evolution works, is that evolution over time can try and optimize the behaviors of a female that can make them different in this period of time, the fertility phase, as compared to other aspects of the cycle. And in fact, mammals are, humans are pretty fascinating. We are one of the very rare organisms that just are on a constant ovulation cycle. Many mammals actually just stimulate ovulation only after they have sex, whereas we are ones where the cycles, in fact, there aren't necessarily any clear, prominent, obvious displays. Again, anybody who has lived in a neighborhood with cats, cats seem to know when other ones are ready to mate and be fertile and, you know, those things are happening. So, again, we do have this thing that's a little bit different than a lot of other mammals out there. Okay, and then the last concept, and this is a concept I come back to many times when I talk about biology. And I hope people can recognize Dr. Strange Love, that, of course, the whole point of a doomsday machine is lost if you keep it a secret. Why didn't you tell the world A? And again, the point here, a doomsday machine is that if you're attacked, then you basically deploy the doomsday machine automatically. You can't stop it, and it destroys the entire world. But if your opponent doesn't know you have it, then they don't know that that's a deterrent to bear attacking you in the first place. And this type of concepts is important also in biology, that, for example, if you are a species that is poisonous, it's not enough to just be poisonous. You also have to tell other species that you're poisonous. And you have to do it in a way that's detectable by the other organisms. So, again, there's this interplay of display and detection that is, again, a key fundamental concept in biology. And, of course, this also has to do with mating behaviors, mating habits. A lot of them are visual. When we think about visual species, some of them are chemical and in fact, in many cases, there's this combination. Okay, so any questions about the basis of what sexual selection, how it's different than natural selection is before we get started? Yeah, there's a question about genetic determinants of pair bonding in a link, and I will hopefully remember to come back to that at the end. All right, so I'm going to go ahead and talk about the science of sex appeal. All right, so one concept, this is something that was shown with Kendra Schmidt, a biostatistician, where she was looking at this concept of the golden rule, sorry, the golden ratio, and it's approximately a two-thirds ratio, where the ratio of the small, or the size of the small stick, the ratio of that to the bigger stick is equal to the ratio of that, sorry, the intermediate stick to the large stick, so two-thirds. And she found that when she asked people to rate the attractiveness of faces, that she also could correlate that with how much they displayed various golden ratios in say the distance between the eyes to the size of the eye, and that's what's shown here on the top right. And so this actually becomes a way of statistically modeling the attractiveness and actually being able to, in a sense, understand the underlying physical features of the face that are correlated with attractiveness. And she came up with this model system, again, being a scale of 1 through 10, where someone like Kurt Dunlis comes out as a 7, again, so again, anything above a 6 is rated highly attractive. And this is a picture of one of her volunteers, where the rating is, again, a little bit lower, and more the range of a 4. And so what's important to keep in mind about this type of rating scale is that now with the power of Photoshop, we can actually take the same face and basically very precisely change those ratios within a face in a way to then re-survey people to ask them about rating attractiveness. Okay, now concurrently with this work, Lisa Dabrine was basically trying to take averages of faces and trying to really determine what are the underlying features that display male-ness versus female-ness. Now, again, I think in your own mind, if you were to think, if you were to look at any given face, you look at that and say, that's a male face or that's a female face. In some cases, you think about very specific individuals. You actually can't have this ambiguity. Again, sometimes if you watch movies or plays, people try to take advantage of this ambiguity, try to, say, use makeup on a male to appear more female. And so, again, she has this power to say, what is a male-ness type feature versus a female-ness feature? And her experiment was this, that she had these individuals and the middle pictures, oh, yeah, actually, let me ask a question. In terms of rating the opposite sex, which one looks the most attractive to you? Now, you don't have to answer a local chat or anything, but just take a quick look and say, oh, the guy on the right or left is what I find more attractive or the woman on the right or left is more attractive than to me. Sorry, I have to cough a second. So, what was actually done in the experiment? And sorry, I should mention that the picture in the middle is just the natural person's face. Okay, and the original human middle, and, again, using these computer algorithms, they created a more feminized face by moving to the right, and they created more masculinized faces on the left. And when they surveyed people, in general, people found about 68% of the time when they were given a choice of the faces, they picked the one that was, again, a man would pick the more feminized face and a woman would pick the more masculinized face. And so, again, one thing to go back to and remind you is that these facial features and developments occurs or is highly modeled and influenced by the surges of hormones during puberty. So, again, very young boys don't look very masculine, right? They don't have a lot of the square jaw and other features. The roundness of some girl's faces and the placement of the eyebrows, like kind of the placement of the eyebrows and the fleshy parts of a woman's face, those things change, again, as they go through puberty. So, again, these are things being modeled and influenced by sex hormones. Okay, in addition, in terms of thinking about sexual attractiveness, let me ask you a question. Does this woman look attractive? So this is going to be a little bit like going to the optometrist. Which looks better? Picture one or picture two? Let me go back. Picture one. Here's picture one. Oh, I've got my back bone somewhere. Okay, picture one. Picture two. Yeah, so Sydney points out that in picture two, her eyes are even. And in fact, it's not just that. If you actually look at picture two, if you look at it very closely, how it was made was they just took a central line of symmetry and they're just basically copied what we're perceiving as the left side of the face onto the right. So if you now look at the hair, if you look very specifically at the hairstyle, it's basically perfectly mirror image of the left-hand side. And so, again, the rating of symmetric faces is higher than asymmetric faces. Okay, so let's go through one more example where I think this was, again, still Kendra Schmidt. She took the man's face and the woman's face. Well, I'm sure she did more than one each. And basically, again, use Photoshop to, again, objectively quantify the amounts of symmetry in the face using, again, a bunch of very specific individual points. And she surveyed people on a college campus. Which one do you find more attractive? Now, she told them these were identical twits and they even put them in different clothes. You know, those are in different clothes. They're the same person, but we're in different clothes. And we're just asking you, which one do you find more attractive? Which one do you find more attractive? This is true for both males and females. You can look at both and say, which one's more attractive? And, again, if you know where I'm going with this, you can actually look at the image ahead of time to figure out which one would, in general, be the correct answer. Yeah, so they are saying the woman on the left for the man sitting here saying the bottom right. And in fact, that's agreeable. That what was done with the Photoshop images was, the woman's face on the left was basically artificially symmetrized and the one on the right was officially skewed in terms of symmetry. And that kind of the opposite was face. Symmetric face was preferred by 8 out of 10 people. 8 out of 10 people referred to this. And what this actually is, again, symmetry in and of itself is not necessarily what is some sort of ideal artistic feature of a face. What the research says is that the more properly programmed your hormonal surges were during development, the more likely you are to be symmetric. Okay, so symmetry is not some sort of aesthetic quality. What it actually is, is a marker, an indicator of a properly carried out developmental program by good genes. Okay, now again, there are other things that can influence symmetry, right? There's things like nutrition, there are things like getting your face punched out and having to get surgery. But as a broad indicator of this programming, this type of genetics, and again, good nutrition through youth as well, and not just say in utero, but also during the surges of hormones in math and puberty that symmetry is something that says, hey, good genes. One other example of these modifications about hormones can affect things is here's a woman's face. And again, I couldn't get this without the text involved. But there's ovulation 14. So again, another optometry situation. Do you prefer one? Or would you prefer two? Yeah, no, I'm giving this in time. Hopefully everyone has a chance to realize these. Well, again, these were taken on different days. So the researchers attempted to make her hairstyle and make up the exact same between the two days. The two different times they took the picture. Okay, we'll go back to number one. Number one, number two. Yeah, Cog points out it's interesting that her skin glows more in the second picture. And what the research says is that in general, if you ask men which one was more attractive, it would be number two. And this is both a detection and display that the surges of hormones that are occurring are important for, say, developing the uterus, are also trying to display that this is a fertile period for her to men. And so to some degree, what's probably happening is there's a little bit more water content in her skin. There might be also a suppression of immune responses in terms of things like acne or things going on skin. And yeah, Aurora mentions it looks like there's a blur filter applied. It does, it really does, but they did not apply one. This was just a natural picture. And so these things that are occurring are, again, trying to create this image of vitality and youthfulness and that's associated with this. But it's really just a display. Your first face were to turn purple, right? That's what baboon butts do, right? Where you try and change coloration during the right phase of your fertility or when you're fertile. That one could easily say let's just have our faces turn purple when we're fertile, but that's not how it works. Okay, another interesting set of research is this ability to... Oh, okay, so Aurora mentioned something and that talking about birth control, the pill, where it's a largely a large constant dose of progesterone. There are some things where the pill knocks off the ability to display and detect these things, which they do mention in the documentary. I don't know more details about it than that. So let's just move up to the side. But it is something that, again, the birth control pill, these changes in hormone levels do make certain differences in how the cycle works. Okay, sorry, I have a dry throat today. Okay, so another interesting technology is asking, well, what's the physicality that draws your eyes, right? What do you look at? And so this is some technology where they're using basically things that scan your eyes and then can tell you on an image where your eyes are looking. Again, this is something that you have in a variety of, like, even, I think, game boxes now. And it's a way for people who are, say, paralyzed to actually be able to communicate by looking at various letters on a keyboard. And you can track this, too. And so here's an example of me looking at it on this image. And the blue dots represent, again, some of the key areas in the amount of time the focus is spent in various areas. So, of course, looking at the face, scanning across the breast. And so one of the accumulated blocks of knowledge from this is that a researcher, again, her name was Kerry Johnson, although it couldn't find her on the web, she developed these models that she tried to make them basically generous in terms of, say, hairstyle, clothing. And that's what she's seen the top right. She asked people, is something a male or female? Does that look like a male or female to you? That's a way of saying, what are standard, basic male versus female characteristics? And something we know from physiology and something that she saw in these models is that this ratio of the waist to the hips is something that is very indicative of the female. And again, this comes back to the idea that women develop in a way that they have wider pelvises. And so this is, of course, something that would be a normal developmental program of reproductive success. Now, what was actually very interesting, though, right? So that was generally tracked with what you'd expect. But one of the interesting aspects of her research was that she asked men what was the ideal shape. It ends up being this 5 to 1, this 0.5 to 1 to 2 ratio of waist to hips. Now, if you look at that, you're probably thinking, that does not look healthy. How could you breathe? And again, is there a certain fashion trend from, say, Europe in the past few hundred years that this is reminiscent of? Yeah, of course that's right. The whole idea, of course, was to really cinch up the waist to basically recreate this ratio. So again, this is something that fashion has been doing for a long time, is trying to recreate and make women more attractive in an artificial way by taking advantage of these things that our brains think of as being most attractive. Now, the conclusion from the research was the idea that, well, if you think about a model in motion and you think about how men actually evaluate a woman's, say, pelvis and waist, it's not when they're just standing there. It's actually when they're walking, right? That, again, if you think of these standing pictures of a woman walking past the guy, he turns around and looks at her. He's actually walking, watching her walk. And that's a part of the movement to the display. So in the research, two years ago, it says, can a woman with a narrow waist be indicative of someone who eats less and costs less to feed? I'm not aware of any sort of sexual selection modeling that says that that would be necessarily a valued or desired trait over just obvious physiological factors. All right, so the experiment here was they took volunteers and they put them on a treadmill and said to half the women, you know, we're putting you on a treadmill and what we're going to have is a person evaluate your walking gait, you know, for whatever reason. Is it a good gait or a bad gait? And then the other half of volunteers, they said to them, you're going to walk in this treadmill and then you're going to be evaluated for how sexy you walk. So this is one of these mind games that have a great research example where the subject really doesn't know what's being evaluated. And so the results of the research were showing that women told that they'd be monitored for their gait. They kind of walk normally, you know, a little bit stiff, straight back, but the women that were told they were being evaluated for sexiness were shifting and walking in a way that was accentuating their butt movement. And so this type of thing is that there's this subconscious, or maybe in some cases they were conscious, but this subconscious idea that in the right environment for that situation that you're going to try and accentuate and display your wares in a way because you are told that that's actually something being looked at. And this was also true for men, this was not true just for women, but for men in the case that men told that they were being evaluated for their sexiness of their walking. They put a lot more of that swagger, that swagger look that you have. And just since we're here in Second Life, I do want to mention that, you know, one thing that we do in Second Life is that we wear animation overwriters, right? And we actually can choose what sort of gait we have when we're walking around. And so one thing to keep in mind is that when you have these choices of this, you have different types depending on your Second Life situation. Here in Science Circle, you're not necessarily trying to attract a mate, you're focusing on other things. But you actually might be choosing different animals when you're in different situations, different islands. All right, so another great research study. And this was, again, this idea of the mating game. How do you actually choose and evaluate a mate, especially when you have competition around? And so the experiment here, that was correct, is taking volunteers and basically desexualizing them as much as possible. They put them in very boring clothes, they covered up their hair, and what they actually gave them was a number, right? So these numbers that are pasted on the forehead is saying the smaller the number, the more desirable the person is. And the game you're playing is trying to get the best you can, get the best number that you can. And what was interesting, of course, is that any given volunteer did know what their own number was. So what this experiment was really trying to evaluate is, within this, like, mixing and matching, do people have this capacity to not just to kind of get a sense of what their own attractiveness gives? And that way they're trying to trade, or they're trying to acquire the best thing that they can, given what their own number is, even though they don't know what their number is, but they can evaluate and take a guess at that based on their interactions with others. Okay, so the results were that people do tend to number match, that if you looked across this in multiple trials, the number matching was very close. So you see a pairing here of a 10 and a 9, and a matching up of a 2 and a 3. Now they actually did this, and they replayed this experiment, where they actually took the volunteers and asked them to evaluate the physical attractiveness of the opposite sex, and then told them, you know, take off their hair stockings, walk around, try and smile, you know, do all those things that you do, and pair off. And in fact, what they showed is that this pairing mechanism or number matching of basically, you know, acquiring and pairing off at your own rating was actually consistently seen within these trials. And so I think this is important here, is that of course your strategy, of course, would always be to trade up as much as you can to acquire a higher number, but that you do have the sense and evaluation of what you are or are not going to have in the end. There's one thing I want to say about this, of course, that one thing that they're not doing in this trial is trying to use makeup, hair coloring, other things that we artificially do to our perceived attractiveness that are in a sense artificial. But of course, in the real world, these are all things that do happen. And again, part of trying to trade up. Okay. But in terms of physicality, there are other things I don't want to say at all maybe as well, but what someone looks like. Okay. So here's another quick example. Again, other features that, again, do we necessarily associate these with this mating game and how do we know that they work this way in sexual selection? And so this research group is basically taking voice recordings and asking others to evaluate which voices they find more attractive. Now what they would do, of course, is take the same voice and just use, you know, audio software to change what it is. So it's not that it's a different person's voice. It's the same person's voice, but just modulated differently. And of course, deeper male voices were preferred by females and higher-pitched voices were preferred by males. So higher-pitched female voices were preferred by males. Now I got a typo there. Now, what is this actually trying to say? Is that one thing that, the reason why men have deeper voices is because testosterone disproportionately compared females lengthens the larynx during puberty. But so again, is there any value to, per se, having a deep voice in and of itself? No. But what it is, it's a display of the hormonal surge that is maleness. And so again, I don't think it's necessarily just having a deep voice because of course, really tall people have naturally deep voices because they have very large larynxes. So I think there's a little bit more subtlety to this. And I've listened to some research that suggests it's the case. It's not merely a matter of, you know, what frequency your voice is working at. And so for example, if you think of something like Andre DeGiant, who had acromegaly, if somehow deep voices, he had a very deep voice, if deep voices were somehow to become a very strong sexual selection and sexual advantage, then if he were to be more successful reproducing, he would also be carrying on a disease staging. This is one thing to keep in mind. I saw, I'm trying to respond to something that they said in text a little bit ago about the costs of how sexual selection works. And there are times where, if somehow the perception of a sexual trait becomes too strong in a population, that there are any, say, physiological downsides to that, then that can be carried along and can actually lead to fitness defects. There are some interesting subtle things about the voice research. It's that female, the preference of a female for the deeper voices is actually influenced by where she is in a menstrual cycle. Again, there's this little bit of physiology she's keen into. But also the female's voice pitch that she's displaying is also influenced by her menstrual cycle. So women that are in that fertility phase will tend to actually accentuate and up the frequency of their voice to be a higher pitch. So I think that's kind of an interesting bit of research as well. Okay, so let's wait for a minute. Let's think about other factors that are really important for having successful offspring. And this is one of, again, another one of my favorites from the research. Here, three men is just, again, they're rating from that study just looking at their physical attractiveness. So we have the nine, the four, and unfortunately, not even a number, all they said was, here's the guy with the lowest rating. So she goes for him for agreeing to still be in the documentary. Now, what they did with these women is they, I'm sorry, with these pictures of the men, then associated what their professions were. And can anybody guess what effect how much money they'd be making what they do would influence their attractiveness? Sorry, Arianna, I don't know who Edith Piaw is. Yeah, so here we go. If you take a nine and turn him into a retail clerk that only earns $23,000 a year, he very quickly becomes a four. And you take someone who's a four and make him a music industry executive earning a quarter million dollars. He becomes an eight. And you take the lowest physical attractive guy and turn him into an entrepreneur with earning even more money. He becomes a 10. And so, a Sydney points out what this is really saying is that women, they, of course, they physiologically evaluate how they, what their mating success can be. But they definitely have, because they have such a huge investment and because they're trying to get the best they can for their offspring because of their strong investment, they want someone who can also strongly support them. And again, in older, you know, pre-civilization trades and how many people didn't have incomes, then, of course, where a man's status was in some sort of system would, of course, be very determined as to that as well. And so, again, I think if you think about the Indian caste system, that's the type of thing where, they force marriages within a caste. There would still be this, like, if they're an ancient, more caste system in older man, then you'd be trying to trade up in caste as well. Okay, so, what are some of the, what's some of the next research? So, they spend a lot more time in the documentary on the first parts. So, I'll go through these a little more quickly with fewer slides. But this one here, and this is something that you might have asked yourself, what's the deal with women smelling men's t-shirts? Again, this was made the popular news every once in a while. And the idea behind this research is that, and what they were doing in the experiment was having men wear shirts, get them all sweaty, and then they, again, contain the smell within jars and ask women to smell them. Now, in general, when, oh, so, Berygon also points out something interesting too. In primates, the female will mate with high status, low status males, especially if the low status males have certain physical characteristics that are very attractive. And that's one thing is that men males don't necessarily know who their offspring are. So, that's something that, again, women still can create diversity physically. And then, especially if the first mate, the one who was a good provider, can then raise this other offspring, even if it's not theirs. Okay, but let's go back to the smell research. And they asked women to rate the smell. Now, in those cases, women did not find this very attractive. But in a small number of cases, they found women that during their fertility phase would find the occasional shirt actually attractive smelling. And so, what was the underlying feature here? There's a guess that the researchers had, which was that when they took a look at the DNA of the men versus the women, where there was this attraction signal, they found that the diversity of the major histocompatibility complex was higher. And I don't want to go through the biology of major histocompatibility complexes, but the bottom line is that it's been shown that an individual who has more diverse of these molecules, and these are highly polymorphic, they are variable within the human population, the more diverse they are, the more fit you are. You have a better immune system and it also correlates with longer, healthier life spans. And so, what the researchers are concluding is that somehow there's a signal and detection via sweat. Again, via the compounds that you find in the combination of sweat and the bacteria that are in armpits and on the body, they somehow signal this diversification of MHC classes. And of course this leads to healthier offspring. But again, a signal detected specifically when a woman is fertile. It's like in Wisconsin, this is known as pheromones. Pheromones are something that are well documented in insect species and other organisms, but still somewhat controversial within humans. Yeah, and again, I think one thing that you think about, I actually told this to a student one time when I was teaching, it's like, you know, if you can find that your guy smells nice to you, that you just like to smell, everything else will work out. Just everything else works out if you'd like to smell. There actually is a kind of flip of the situation where, I might have actually double clicked here, that there are these compounds that researchers have detected in females in these copulins and the copulins what they show in this research, they're feeding these copulins to men through contained air and asking them to rate the attractiveness of females. And what actually happens is, they lose the ability to distinguish attractiveness. So women that were formerly being invaded as 8, suddenly becomes 5, women who were 3 are also becoming 5s, that there is some sort of physiological effect of these copulins, which again, I will just mention, not probably a word you hear very often in those conversations that are derived from vaginal secretions. Yeah, Aurora asks, was that really the best sample source? Again, you think this, I don't think they are necessarily, they know these compounds exist, but in terms of trying to purify large quantities for these experiments, you end up usually just providing a mixture of these smells. So again, I don't know that you can go to Sigma Aldrich now and buy copulins as some sort of specific compound, but again, a lot of times you just have to go with kind of a raw source that you know is the origin of them. So speaking of brain physiology, there is a lot that we now know about how the brain reacts, and the chemicals are important for this. Oh, sorry, sorry, so Aurora, again, just because an experiment they're driving from vaginal secretions that doesn't mean that in a social situation like a bar or whatever, that copulins can only be detected from that source, right? That would be a very awkward, of course, social situation. What's actually going on is that there are levels of copulins that are coming out of sweat, coming out through the air. These things have to be something that are aromatic, but just for experimental purposes they derived them from a higher concentrated source if that was the confusion. And so again, something we now know is that in many ways that early phases of being attracted to someone really is this related to dopamine. And again, dopamine is something that we know is related to addiction. And again, I put addiction in quotes because I think that you want to be cautious of acclaiming something like dopamine as a sexual behavior response to, again, how it also could be triggered by, say, things like cocaine or with also now known sugar. But again, people have monitored brain scans and found this ventral and tegmental area where when women or men are just in those very early periods of less than desire being somebody new, these things are firing, right? These are things that our brains are doing physiologically. Neurons are firing to say, hey, this person is great, right? And that's probably because the brain is integrating the system of saying, you know, we've subconsciously detected all these things. And you know, your consciousness probably not good at evaluating mates as we are at all the things that have been occurring during millions of years of evolution. So we're going to fire neurons and try and tell you, hey, keep hanging out with this person, keep getting with this person. And so but interestingly, of course, in organisms that have, where there whatever reason over evolutionary time has selected a pair bond, where they get the combination of the male sticking around with the female to more successively raise offspring, they've actually found these physiological responses that lead and help drive this pair bond. So an example up here is looking at vasopressin, which is this compound that's actually involved in other roles of physiology in the form, actually are involved in the constriction and vasodilation of blood vessels. But this is a common theme in biology where one compound can be used for multiple roles within the body. And that they actually see differences in activity between the promiscuous vol brain versus the monogamous vol brain. And what they also talked about in terms of humans, they had this couple that have been together for, I think like 30 years, they're a really cute little couple I know what the guy thinks is Peter. And again, they've taken couples like this and looked at their brain and tried to understand what is this long-term love? What is the brain physiology of long-term love? And so there's this region of the brain that was the caudate nucleus, which seems to be involved and is fired in these longer pair bonding situations. But what's actually interesting about this particular couple and the research that was being done by Lucy Brown and Helen Fischer is that in some of the individuals you actually see that dopamine has come back. That dopamine has been searched at a constant level. So these feelings of like addiction and satisfaction for your mate is something that comes back. Because actually this is something, anybody here, there's a Marilyn Monroe movie which is a concept of marriage that people, anybody offhand know the movie I'm talking about? This is something that's actually in marriage circles. Something known as the seven-year itch. And so this idea of the seven-year itch is something that the researchers were showing that what actually happens is within two people who have decided to have a monogamous relationship that dopamine levels can start to trail off in about four years. And so this idea of satisfaction is like addictive type quality is something that can fade. Again, people have suggested it has to do with the lack of novelty that's the same person over and over. And so the researcher was suggesting that what really occurs in these very long lasting pair bonds is that you have this like maybe constant novelty or something where people approach it in a way that they're always finding them interesting and new and so that other like attractions and what not do not get distracting. There are a lot of questions. There's this bias in thinking about research that because we've identified certain compounds that we know work really well doesn't mean there aren't tons and tons of other molecules or tons and tons of other states and molecules that in combination are very influential and important. Okay, so again, it's not all loving roses though like in the marriage game and this is something they talk about at the end of the video. They don't go too much into the research. It's that of course one thing we do have are mating signals with body motion and showing skin. Again, this is something that again in terms of modern scientific experimental design you can quantitatively measure these types of things by using motion capture as well as looking at photoshop images and looking at proportion of skins and what about. Okay, I'll try to come back to that in the conversation phase. I think this is good to realize that we do have this physiology but of course we, in terms of what we evaluate as being valuable in the mate and having successful offspring, there are other more complicated things going on. Okay, so again, what was interesting about this research was that they were showing that even married women during their fertility phase and I don't know if they necessarily measured the number of offspring that they would actually show these additional mating displacements during their fertility and so the concept here in this is still I think a bit theoretical out of the current research is but that married women still like the look of masculine men and are kind of like as we mentioned earlier with apes from the local chat is that there might still be this idea that for some women in terms of having successful offspring but they might still be in a mating game even though they've already are in a marriage or are already in a paragon leading the hazard is supposed to have offspring. Okay, so that kind of concludes I think the main pieces of research from the video. There actually are a couple other little items and tidbits that I picked up that I want to talk about before we just conclude and that is this next one is an interesting one where there's this paper, this research site and this is actually done by business people these are economists where they looked at the fact that strippers or pole dancers and lap dancers were elevated their earnings were elevated during their fertility phase so again, they were measuring this, they were measuring the exchange of money it's something we can quantify as the exchange of money so suggesting that again there's both maybe a combination of both the extra movement and display to be more sexual from the women and then perhaps also the males picking up on these signals to then say I'm going to give you more money I'm going to show you how much more I could say how much money I have to do this. So again coming back to the idea of the mating signals again the only effect that this particular documentary talked about in terms of birth control was that the ability for women to pick up on the scent of an MHC class diverse male was lost again, I don't know the documentary did not go into that research more and it gets something that you know, you can always start looking up but I don't know of hand either okay, and then another little interesting thing that I will mention is oxytocin so again, talk about chemicals talk about hormones the oxytocin is something that has been put out in popular media quite a bit as well that again, we know it's involved in pair bonding we know it's involved in feelings of trust involved in feeling of relationship both for men and women and I don't want to go much into but this is one of the ones where you know there's a lot of interesting quantitative data you can put into this to really understand the physiology about oxytocin effects men and women but this is one where the ability to detect the surgeons of oxytocin again, in women especially during fertility, post fertility or post birth you can actually measure these things and then of course the last thing we'll talk about again these factors, all these hormones physiology and again there's a bit of text from Dar what are other things that are indicative of success especially, remember we're now in a culture where our brains might want to adapt to things that aren't just physiological they're not just the cast system that's just some guy's strength or some kind of surge maybe other things like intelligence or maybe other things like humor and so this is again, this is a time this is highlighted I think most recently with that what are the SNL Pete Davidson who again, let me just say it's a part of his bit to remind everyone in the audience that he's an unattractive guy well I find him really funny in Silent Live he's engaged this week or last week to Ariana Grande again a woman considered I think of music industry again, an example of a very pretty young woman so these guys are now engaged and so the idea of human intelligence is something that's also been for this time, remember a lot of this research that's kind of basic biology was done in the early 2000s and so we're still in that phase of research again, post the timing of this documentary which is now nine years old of what we actually now understand is these interactions that occur between males and females alright so just in summary I just want to remind people to point out that this is actually kind of important stuff that the way we interact with people the way we're trying to be evolutionary successful and the way we've been programmed the way our physiology, our brains or genetics has programmed us from basically the dawn of being a male or maybe just and also maybe being a primate these are things that drive our behavior and so we're reminded that attractiveness is this display of developmental correctness in fitness and that of course you have to have these ability to detect this in the opposite sex and those fires in our brains are a rating system genetic diversity, something that we know is important for offspring success is something that is basically something that can be put out there displayed and detected and these are things that we can actually detect physiologically with both neurochemicals and brain scans that we really just understand this well now that our species in general has a strategy of pair bonding to raise what are difficult to deal with in many ways offspring up through the age of 18 and now in some cases still stand at home through the age of 55 that these other types of changes and differences are things that can affect culture and interaction alright so I will conclude there and thank you all for your attention hope you enjoyed it again I think this is something that when Darwin proposed the theory of evolution you know there's a lot we've learned since then and so it's important in the conversations about what we think of this evolution there's a lot more we know yeah thank you for coming thanks for coming today Mike, Baragon Serena again thanks to Chantal and Josson, Jess for organizing and hosting yeah I okay so the documentary doesn't really cover you know the concept of homosexuality and I think I'm also going to just purposely bypass what could ultimately be a very difficult conversation but I think that thanks for coming Aurora yeah I again from a basic biological programming point of view homosexuality strictly enforced does not lead to successful offspring and so I think the way one thinks about that concept from biological perspectives is very complicated but certainly and I don't know but I would presume that again let's say your brain's behavioral status update is that you do find same sex men as a man you find men attractive what are the things that lead to the things you find most attractive and I think you know when you think about again my very basic understanding of the gay community that there are very feminine looking men that are considered attractive there's also the concept of the bears which are very, very masculine looking men that are considered very attractive so it would surprise me if there's something where within a gay individual it's either going to attract, the brain might attract to find more masculine attractive or more feminine attractive depending on maybe some sort of middle state of what you really consider yourself to be does that make sense? yeah so I think Synergy kind of points out this idea that you know intelligence, how does intelligence mean you know mating preference and selection and chances of success and I have two ways of thinking about that that one the things that make us intelligent what we consider like human intelligence those may just be reflective of things that have to that were related also to say good hunting skills in primates before civilization so intelligence may be a way of displaying that you know we have lots of traits and capacities but again I think with modern ways of thinking that you know your success as a professional in today's society Western society is so linked in many ways to cognitive capacity and not just intelligence, maybe also social ability, emotional intelligence that these are things that are going to maybe evolve and develop in a slightly different way sorry, Synergy mentions how homosexual men have moms are very fecund I think there's this one model for how again there is data showing that 4th, 5th, 6th and subsequent children from the same mom have a higher prevalence of homosexuality sorry the male offspring the male offspring from the same mother have this tendency and so one thing I do get concerned about is that that's not a genetic component it could be something where the amount of nutrition, the amount of supportive environment, or maybe even just the age of the mother have these effects on the likelihood of homosexuality in the male offspring they're not a female, I actually looked this up because I had a question from somebody about that a few months ago and the data does not support that homosexuality in daughters has anything to do with birth order and there's this concept so Spina Bifida is a very more clear obvious example where as the spine is developing this one area doesn't finish closing and so you have a bad development and that's actually related to a lack of folate in the mother's diet during pregnancy and so you can imagine that either A having multiple children has kind of changed her physiology or she's older so her folate levels are as high or maybe she's just so distracted by having multiple children that she's not getting adequate nutrition and so these are things that I think birth order is something people are trying to understand a little better but we don't necessarily have a strong chemical physiological understanding of everything that happens differently oh okay so I missed the early part of the conversation one thing that's pretty amazing about humans is that we have this capacity to be very adaptable to different environments we're not like the best at almost anything but we're very good at a lot of things again I'm not sure these are things that definitely have trends of natural selection to that one so I'm not sure I don't want to go too much into that in a conversation about sexual selection any other things I can clarify? any burning questions from the talk are there any orders associated with pair bonding in men? anyone in the sense of a woman trying to that a man is detecting a woman's fertility cycle or something by smelling I'm not aware of any one thing I will say is that there are a lot of visual signals that women display and that men are detecting and I think one thing we kind of generally feel about men is that they do tend to be very visual and so it may be that this physiology of smell is not as important but it may also just be something that we haven't quite found the right example or found or detected it in women being presented to men in the fashion season acts bias but yeah so perfumes and colognes are kind of a kind of interesting topic right? that we definitely associate certain things with smell that are good and bad and so clearly smell doesn't have this key feature of what we do in our tech but in terms of as far as what I know the current research is that women are really trying to detect some degree of this interaction between males and females so one thing that body sprays and diodes will do is they will limit the growth of the bacteria that are on men and so again women do have smells again don't get me wrong women do have smells and you can definitely say that a woman absent any sort of fragrance smells good or bad and so I believe Susan that there is something related to that but I don't know the science behind it or if anything has been specifically detected well you know perfume my understanding of perfume in terms of our most recent western civilization is that once humans started living together in high concentration densities things must have smelled really bad because basically the streets were the bathrooms people didn't have opportunities to shower very often because now the access to water was limited to like outside the house and yeah bathing was unpleasant right so of course people use perfumes to mask smells related to dirtiness and so of course should use that for that purpose and that would be a part of a mating game and selection of people who can afford good perfumes would be more attractive but I don't know I don't know people who wouldn't essentially use fragrances to try and be attractive to the absence of sex or to try and not be disgusting to everybody would be another way of putting that but I think there are some oddball things like when I think of a woman wearing very flowery fragrance I do have a sense of femininity to flower smells right I would not wear you know I don't know a smell I would not wear a violet perfume myself to try to make myself attractive to the opposite sex and I don't see why a woman would wear like letter the scent of letter to be attractive to me because there are these like cognitive associations we do have but I think there's one video for you just like if men could just rub money smell on them maybe that would help out chocolate would be a great perfume my favorite smells scent is vanilla I don't think I have any sort of necessary sexual attraction to that scent but I don't like the smell so if you're introducing something that makes somebody feel happy then maybe that is something that if you get this like it's like Pavlov's Dollars Incense that if you have this association of happiness with a person then that starts creating that type of you know allure to me yeah I'm smelling like I don't know rosemary the thing I just want to point out our physiology is kind of meant to detect certain physiological signals so artificial sense well they may play roles in some sort of degree of happiness or associations I don't know that there's a lot of data suggesting that they are specifically genetically favored for detection thanks everyone thanks again for coming thanks for your channel all these documentaries are great I recommend watching lots of documentaries I think I am going to go off voice have a good day everyone