Muscular Strength By Gender and Race
2000 words
It’s a known fact that men are stronger, but how much stronger are we really than women? Strength does vary by race as I have covered here extensively. However, I took another look at the only paper that I can find in the literature on black/white strength on the bench press and found one more data point that lends credence to my theory on racial differences in strength.
Strength and gender
Men are stronger than women. No one (sane) denies this. There are evolutionary reasons for this, main reason being, women selected us for higher levels of testosterone, along with differences in somatype. Now, what is not known by the general public is just how much stronger the average man is compared to the average woman.
Miller et al (2008) studied the fiber type and area and strength of the biceps brachii and vastus lateralis in 8 men and 8 women. They were told to do two voluntary tests of strength, using elbow flexion (think biceps curl) and knee extension. (Note: I am assuming they are exercises similar to biceps curls and knee extension, as the authors write that they had custom-made equipment from Global Gym.) They also measured motor unit size, number, and activation during both movements.
The women had 45 percent smaller muscle cross-section area (CSA) in the brachii, 41 percent in the total elbow flexor, 30 percent in the vastus laterus, and 25 percent smaller knee extensors. The last point makes sense, since women have stronger lower bodies compared to their upper bodies (as you can see).
Men were significantly stronger in both upper and lower body strength. In the knee extension, women was 62 and 59 percent of male 1RM and maximal voluntary isometric contraction (MVC) respectively. As for elbow strength, women were 52 percent as strong as men in both 1RM and MVC. Overall, women were 70 and 80 percent as strong as men in the arms and the legs. This is attributed to either men’s bigger fibers or men putting themselves into more physical situations to have bigger fibers to be stronger (…a biological explanation makes more sense). However, no statistical difference between muscle fibers was found between gender, lending credence to the hypothesis that men’s larger fibers are the cause for greater overall upper-body strength.
The cause for less upper-body strength in women is due the distribution of women’s lean tissue being smaller. Women, as can be seen in the study, are stronger in terms of lower limb strength and get substantially weaker when upper-body strength is looked at.
Other studies have shown this stark difference between male and female strength. Men have, on average, 61 percent more total muscle mass than women, 75 percent more arm muscle mass, which translates approximately into a 90 percent greater upper body strength in men. 99.9 percent of females fall below the male mean, meaning that sex accounts for 70 percent of human variation in muscle mass and upper-body strength in humans (Lassek and Gaulin, 2009). Women select men for increased muscular size, which means increased testosterone, but this is hard to maintain so it gets naturally selected against. There is, obviously, a limit to muscle size and how many kcal you can intake and partition enough kcal to your growing muscles. However, women are more attracted to a muscular, mesomorphic phenotype (Dixson et al, 2009) so selection will occur by women for men to have a larger body type due to higher levels of testosterone.
Strength and race
The only study I know of comparing blacks and whites on a big three lift (bench pressing) is by Boyce et al (2014). They followed a sample of 13 white female officers, 17 black female officers, 41 black male officers and 238 white male officers for 12.5 years, assessing bench pressing strength at the beginning and the end of the study. The average age of the sample was 25.1 for the 41 black males and 24.5 for the 237 white males. The average age for the black women was 24.9 and the average for white women was 23.9. This is a longitudinal study, and the methodology is alright, but I see a few holes.
An untrained eye looking at the tables in the study would automatically think that blacks are stronger than whites at the end of the study. At the initial recruitment, the black mean weight was 187 pounds and they benched 210 pounds. They benched 1.2 times their body weight. Whites weighed 180 pounds and benched 185 pounds. They benched 1.02 times their body weight. Black women weighed 130 pounds at initial recruitment and benched 85 pounds, benching .654 times their body weight. White women weighed 127 pounds at initial recruitment and bench 82 pounds, benching .646 times their body weight. Right off the bat, you can see that the difference between black and white women is not significant, but the difference between blacks and whites is.
At the follow-up, the black sample weighed 224 pounds and benched 240 pounds while the whites weighed 205 pounds benching 215 pounds. Looking at this in terms of strength relative to body weight, we see that black males benched 1.07 times their body weight while whites benched 1.04 times their body weight. A very slight difference favoring black males. However, there were more than 5 times the amount of whites in comparison to blacks (41 compared to 238), so I can’t help but wonder if the smaller black sample compared to the white sample may have anything to do with it.
Black women weighed 150 pounds at the follow-up, benching 99 pounds while white women weighed 140 pounds benching 90 pounds. So black women benched .66 times their body weight while white women benched .642 times their body weight.
Another thing we have to look at is black body weight compared to bench press decreased in the 12 years while white body weight compared to bench press was diverging with the black bench press compared to body weight.
Furthermore, this study is anomalous as the both cohorts gained strength into their late 30s (testosterone begins to decline at a rate of 1-2 percent per year at age 25). It is well known in the literature that strength begins to decrease at right around 25 years of age (Keller and Englehardt, 2014).
Another pitfall is that, as they rightly point out, they used skin caliper measuring on the black cohort. It has been argued in the literature that blacks should have a different BMI scale due to differing levels of fat-free body mass (Vickery et al, 1988). Remember that black American men with more African ancestry are less likely to be obese, which is due to levels of fat-free body mass. Since fat-free mass is most likely skewed, I shouldn’t even look at the study. I do believe that black Americans should have their own BMI scale; they’re physiologically different enough from whites—though the differences are small—they lead to important medical outcomes. This is why race most definitely should be implemented into medical research. The authors rightly state that when further research is pursued the DXA scan should be used to assess fat-free body mass.
Unfortunately, the authors did not have access to the heights of the cohort due to an ongoing court case on the department for discrimination based on height. So, unfortunately, this is the only anthropometric value that could not be assessed and is an extremely important variable. Height can be used to infer somatype. Somatype can then be used to infer limb length. Longer limbs increase the ROM, in turn, decreaseing strength. The missing variable of height is a key factor in this study.
Finally, and perhaps most importantly, they assessed the strength of the cohort on a Smith Machine Bench Press.
- The Smith Machine is set on a fixed range of motion; not all people have the same ROM, so assessing strength on a smith machine makes no sense.
- To get into position for the Smith Machine, since the bar path is the same, you need to get in pretty much the same position as everyone else. I don’t need to explain the anatomical reasons why this is a problem in regards to testing a 1RM.
- An Olympic bar weighs 45 pounds, but numerous Smith Machines decreases the weight by 10-20 pounds.
- Since the individual is not able to stabilize the bar due to the machine, the chest, triceps, and biceps are less activated during the Smith Machine lift (Saeterbakken et al, 2011)
Due to all of these things wrong with the study, especially the Smith Machine bench press, it’s hard to actually gauge the true strength of the cohort. Depending on the brand, Smith Machines can decrease the load by 10-30 pounds. Combined with the unnatural, straight-line bar path of the movement, it’s not ideal for a true strength test.
Conclusion
Gender differences in strength have a biological basis (obviously) and are why women shouldn’t be able to serve in the military and transgendered people shouldn’t be able to compete with ‘the gender they feel that they are’ (coming in the future).
The more interesting topic is the one on racial differences in strength. The untrained eye may read that paper and walk away assuming that the average black person is somehow stronger than the average white person. However, this study is anomalous since the cohort gained strength into their 30s when the literature shows otherwise. The biggest problem with the study is the Smith Machine bench press. It is not a natural movement and decreases muscle activation in key areas of the chest and triceps which aid in power while doing a regular bench press. Due to this, and the other problems I pointed out, I can’t accept this study.
Of course, height not being noted is not the fault of the researchers, but more questions would be answered if we knew the heights of the officers—which is an extremely critical variable. White males also gained more lean mass over the course of the study compared to blacks—47 percent and 44 percent respectively—which, as I pointed out, is anomalous.
There is more to HBD than IQ differences. I contend that somatype differences between the races are much more interesting. I will be writing about that more in the future.
Furthermore, for anyone with any basic physiology and anatomy knowledge, they’d know that different leverages affect strength. The races differ in somatype on average and thusly have different leverages. This is one out of many reasons why there are racial differences in strength and elite sports. Leverages and muscle fiber typing.
My points on racial differences in strength still hold; the anthropmetric data backs me up, elite sporting events back me up. My theory as a whole to racial differences in sports is sound, and this study does nothing to make me think twice about it. There are way too many confounds for me to even take it seriously when reevaluating my views on racial differences in strength. This study was garbage to assess absolutely strength due to the numerous things wrong with it. I await a more robust study with actual strength exercises, not one done on an assisted machine.
References
Boyce, R. W., Willett, T. K., Jones, G. R., & Boone, E. L. (2014). Racial Comparisons in Police Officer Bench Press Strength over 12.5 Years. Int J Exerc Sci 7 (2), 140-151.
Dixson, B. J., Dixson, A. F., Bishop, P. J., & Parish, A. (2009). Human Physique and Sexual Attractiveness in Men and Women: A New Zealand–U.S. Comparative Study. Archives of Sexual Behavior,39(3), 798-806. doi:10.1007/s10508-008-9441-y
Keller K, Engelhardt M. Strength and muscle mass loss with aging process. Age and strength loss. MLTJ. 2013;3(4):346–350.
Lassek, W. D., & Gaulin, S. J. (2009). Costs and benefits of fat-free muscle mass in men: relationship to mating success, dietary requirements, and native immunity. Evolution and Human Behavior,30(5), 322-328. doi:10.1016/j.evolhumbehav.2009.04.002
Miller, A. E., Macdougall, J. D., Tarnopolsky, M. A., & Sale, D. G. (1993). Gender differences in strength and muscle fiber characteristics. European Journal of Applied Physiology and Occupational Physiology,66(3), 254-262. doi:10.1007/bf00235103
Saeterbakken, A. H., Tillaar, R. V., & Fimland, M. S. (2011). A comparison of muscle activity and 1-RM strength of three chest-press exercises with different stability requirements. Journal of Sports Sciences,29(5), 533-538. doi:10.1080/02640414.2010.543916
Vickery SR, Cureton KJ, Collins MA. Prediction of body density from skinfolds in black and white young men. Hum Biol 1988;60:135–49.
Brain Size Increased for Expertise Capacity, not IQ
2000 words
One of the HBD’s supposed biggest findings is that IQ increases as a function of distance from the equator. The theory holds that those groups who experienced colder winters were selected for levels of higher g and they passed on their high IQ genes. Cold winter theory is supposed to explain why some races have higher levels of achievement and IQ than others. However, after a conversation with PumpkinPerson about cold winter theory and tool use, something clicked in my head: the real reason for the increase in brain size in peoples further from the equator wasn’t for IQ, but expertise capacity. I will go through the reasons how and why our brain size increased for the capacity for expertise and not IQ and hopefully put the cold winter theory to rest for good.
Tool complexity/use and brain size
PumpkinPerson is one of the biggest champions of the cold winter theory, writing: “I don’t even understand how one can believe in racially genetic differences in IQ without also believing that cold winters select for higher intelligence because of the survival challenges of keeping warm, building shelter, and hunting large game.” He wrongly assumes that climate theories are the only explanation for racial gaps in intelligence when other theories (such as differing types of sexual selection) could explain the gap just as well. However, since Rushton and Lynn have pushed this theory for 30+ years, it’s still engrained in the minds of some people. It is hard to change your views in the face of contrary data, but for those of my readers who are proponents of cold winters increasing IQ, I hope tonight I can sway you into believing that brain size increased as a function of climate and tool-making, not for IQ.
In his article he cites Richard Lynn (2006: 148), saying:
… hunter-gatherer peoples in tropical and subtropical latitudes such as the Amazon basin and New Guinea typically have between 10 and 20 different tools, whereas those in the colder northern latitudes of Siberia, Alaska, and Greenland have between 25 and 60 different tools. In addition, peoples in cold northern environments make more complex tools, involving the assembly of components, such as hafting a sharp piece of stone or bone onto the end of a spear and fixing a stone axe head onto a timber shaft.
I, of course, don’t doubt that peoples in cold northern environments need more (and complex) tools compared to those in tropical climes. But I look at it from a different point of view.
This is based on the research of Terrence (1983) and his study on time budgeting and hunter-gathering technology. The data does show that the number of tools correlates to latitude, but he leaves out that it also correlates with mobile and immobile and diet. That’s a pretty big factor. Of course, the type of animals around and what you need to do to kill/extract the meat involves a certain type of complex tool. In northern environments, a few more tools are needed to survive, so what? That doesn’t really mean anything. The whole brain-size/IQ latitude cold winter theory can be explained in another way.
Tool use increased our brain size throughout our evolutionary history, so with Arctic peoples living in cold climes where having a bigger brain is advantageous, they already had more neural columns for expertise capacity. The construction of complex tools increased brain size along with the colder climate. If tool use can explain part of the increase in our brain size over 3 million years, why can’t it partly explain why Arctic peoples—who use more (and complex) tools—larger brains over those further from the Arctic? Because brain size increased for expertise capacity, not IQ. Since they had bigger brains they were able to master the creation of complex tools, which further increased their brain size along with colder climates. Those who could make better tools could pass their genes, selecting for bigger brains.
Brain size increased for expertise capacity, not IQ
Table 3.1 in Torrence (1983) makes reference to technounits, a way to gauge the complexity of a particular item (Collard et al, 2011). Those in northerly climes do have tools with higher technounits, however, that’s showing that what is needed to construct the tools is a high capacity for expertise.
Skoyles (1999) posits that brain size increased for expertise capacity, not IQ. Bigger brains cause extreme complications during birth, calling for Caesarian sections (which is driving the evolution of bigger heads), so selection for bigger brains must have been advantageous in another way. Skoyles cites studies showing that microcephalics have brains in the average range of Erectus while having IQs in the normal/above average range. This implies that Erectus could have had IQs in our range, and that selection for bigger heads was caused by something else—the need for expertise.
Even then, the correlation between brain size and IQ cannot be invoked here. A .33-.4 correlation between brain size and IQ still leaves a lot of room for people to have brain sizes in the range of Erectus and still have above average IQs. Assuming a correlation of .51, that leaves 74 percent of the brain size/IQ correlation unexplained. This leaves a lot of room for other explanations for the remaining variance.
So if you think of the implications of Skoyles’ (1999) paper in regards to human races and the quote provided from Lynn (2006), you can look at it as Arctic peoples needed to be able to learn how to make complex tools which required a certain amount of expertise. Acquiring certain types of expertise does lead to certain local changes in the brain due to environmental demands, for instance in racecar drivers (Bernardi et al, 2013) and in taxi drivers in London who were “on The Knowledge” (Maguire et al, 2000). Tool use did cause increases in our brain size in our ancestral past, so the fact that Arctic peoples have bigger brains but lower IQs is explained by brain size being selected for expertise (their expertise to make their numerous tools) and cold climates but cold temperatures do NOT explain intelligence differences between the races.
Expertise
Indeed, there is evidence that ‘chunks’ form in the brain due to certain types of expertise (Gobet and Simon, 1998). In their study, Gobet and Simon showed that Chess masters used significantly more chunks, extending the chunking theory ” to take account of the evidence for large retrieval structures (templates) in long-term memory.” This study is direct evidence for Skoyles’ contention on “informational chunks (Skoyles, 1999) lending credence to the claim that people who master something have more information stored in their ‘chunks’.
Furthermore, high and low skill employees organize their conceptual knowledge about a problem differently (Lamberti and Newsome, 1989). Low-skilled workers performed much faster on the tasks that needed concrete information organization whereas high-skilled workers were better on the more abstract concepts. Overall, both high- and low-skilled workers processed the same information differently. This study has nothing to do with IQ itself, just how high- and low-skilled workers process information differently (which may come down to ‘chunks’ in the brain).
Chase and Simon (1973) show that the amount of information extracted during a memory and perception task is directly related to the amount of time the individual has played chess. They state that chess skill is “reflected in the speed with which chunks are perceived in the perception task and the size of the chunks in the memory task.” Of course, you can’t just throw anyone into a chess game who has never played before—IQ be damned—and expect them to do well. You need to hone your strategy and skill over time by noticing all types of moves, thinking ahead and guessing what your opponent will do ahead of time. This all takes time playing the game, and since people who have played longer can more easily tap into the ‘chunks’, this shows that chess skill is largely a function of time spend playing (note: IQ is still important, of course. Just, practice makes perfect and one with practice and a low IQ will beat someone with no/little practice and a high IQ).
Expertise does, indeed, take deliberate practice. Practice DOES make perfect.
Conclusion
Our brains increased evolutionarily speaking as to acquire more expertise. Bigger brains (and therefore bigger heads) cause problems with childbirth and so natural selection must have selected bigger brains since they increase expertise capacity. The fact that there are numerous people in the world with Erectus-sized brains and IQs in the normal/above average range lends credence to the claim. Erectus could have possibly had intelligence level near our own. But what really needs to be thought about here is this: It just so happens that the brain size increase corresponds with the beginnings of our modern gait and pelvis (Lieberman et al, 2006). The beginnings of cultural acquisition and transference began around that time (Herculano-Houzel and Kaas, 2011) and so our brain size would have increased due to cooking allowing us to have the energy for a bigger brain with more neurons.
Of course Erectus would need to become an expert with the new-found technology he acquired. Over time, the more ‘expert’ Erectus would have passed their genes on, both for increased brain size and expertise, and the hominin brain size then increased.
Looking at racial differences in brain size while thinking about how expertise capacity increases brain size and thinking about tool use/complexity of Arctic peoples is an alternate (and in my opinion) better theory of explaining racial differences in brain size. I obviously don’t believe that brain size differences cause IQ differences, the brain size differences are a function of climate and tool use/complexity. To make complex tools you need a sort of ‘expertness’, which, as Skoyles argues, causes brain size to increase. This explains the so-called anomalous Inuits with a brain size equal to that of East Asians but with an IQ in the low 90s.
Put simply, complex tools+cold winters+ cooked food=big brains. Cold climates DO NOT by themselves CAUSE higher levels of g. It’s just a correlation, it does not mean that it is causal. Big brains retain heat better in the cold whereas smaller heads cool better. That’s the reason for racial brain size differences, but climate and brain size in and of themselves do not CAUSE racial differences in IQ.
I now believe that sexual selection is a cause for racial differences in IQ, but that’s for another day.
References
Bernardi, G., Ricciardi, E., Sani, L., Gaglianese, A., Papasogli, A., Ceccarelli, R., . . . Pietrini, P. (2013). How Skill Expertise Shapes the Brain Functional Architecture: An fMRI Study of Visuo-Spatial and Motor Processing in Professional Racing-Car and Naïve Drivers. PLoS ONE,8(10). doi:10.1371/journal.pone.0077764
Chase, W. G., & Simon, H. A. (1973). Perception in chess. Cognitive Psychology,4(1), 55-81. doi:10.1016/0010-0285(73)90004-2
Collard, M., Buchanan, B., Morin, J., & Costopoulos, A. (2011). What Drives the Evolution of Hunter–Gatherer Subsistence Technology? A Reanalysis of the Risk Hypothesis with Data from the Pacific Northwest. Culture Evolves, 341-358. doi:10.1093/acprof:osobl/9780199608966.003.0020
Dr. John R. Skoyles (1999) HUMAN EVOLUTION EXPANDED BRAINS TO INCREASE EXPERTISE CAPACITY, NOT IQ. Psycoloquy: 10(002) brain expertise
Gobet, F., & Simon, H. A. (1998). Expert Chess Memory: Revisiting the Chunking Hypothesis. Memory,6(3), 225-255. doi:10.1080/741942359
Herculano-Houzel, S., & Kaas, J. H. (2011). Gorilla and Orangutan Brains Conform to the Primate Cellular Scaling Rules: Implications for Human Evolution.
Lamberti, D. M., & Newsome, S. L. (1989). Presenting abstract versus concrete information in expert systems: what is the impact on user performance? International Journal of Man-Machine Studies,31(1), 27-45. doi:10.1016/0020-7373(89)90031-x
Lieberman, D. E., Raichlen, D. A., Pontzer, H., Bramble, D. M., & Cutright-Smith, E. (2006). The human gluteus maximus and its role in running. Journal of Experimental Biology,209(11), 2143-2155. doi:10.1242/jeb.02255
Lynn, R. (2006). Race differences in intelligence: An evolutionary analysis. Augusta, Ga.: Washington Summit Publishers.
Maguire, E. A., Gadian, D. G., Johnsrude, I. S., Good, C. D., Ashburner, J., Frackowiak, R. S., & Frith, C. D. (2000). Navigation-related structural change in the hippocampi of taxi drivers. Proceedings of the National Academy of Sciences,97(8), 4398-4403. doi:10.1073/pnas.070039597
Torrence, R. (1983). Time budgeting and hunter-gatherer technology. In G. Bailey (Ed.). Hunter-Gatherer Economy in Prehistory: A European Perspective. Cambridge, Cambridge University Press.
Testosterone and Society
1050 words
In my last post on testosterone, I showed how the alarmism against having high testosterone is blown out of proportion. The hormone testosterone was extremely important in our evolutionary history, with skull changes that are affected by testosterone changing, indicating that it’s a cause of the rise of civilization. By looking at the skulls and skeletons of our hominin ancestors, we can infer how high the testosterone was due to changes in their skeletons over time. It seems that a decrease in testosterone was partly responsible for the advent of civilization, but too low of a dip is causing problems in the West.
Testosterone on its own is very important for male fertility, and confidence with there being no evidence showing causation in regards to prostate cancer. There are, however, large increases and dips and testosterone throughout evolutionary history. This can be inferred from looking at the skeletal remains of our ancestors.
One such study was completed by Cieri et al (2014). Cieri et al found that there was substantial feminization of Homo sapiens facial anatomy. Most notably there were reductions in average brow projection and the shortening of the upper facial skeleton. If you have knowledge of testosterone and its effects on the body, this is not surprising. Relaxing either testosterone or androgen sensitivity will cause softer, more feminized facial features over time. They argue that changes in craniofacial morphology reflects reduction in circulating levels of testosterone, “or reduced androgen receptor densities”, which, they argue “reflect the evolution of enhanced social tolerance since the Middle Pleistocene.”
The reduction in human craniomorphology coincides with larger populations from the Agricultural Revolution, which meant greater social tolerance and reduced aggression towards the group. Due to this, people were more altruistic to each other. Men that were more altruistic and had more pro-social behaviors, for instance, would be able to trade with other men in the band, which became sort of a fallback when they couldn’t forage any food. Over time, those men who could cooperate better (and had more feminized craniomorphology due to less circulating testosterone/androgen receptors).
Due to the selection of more pro-social behaviors, humans started becoming less aggressive and facial features became more feminized (due to less circulating testosterone/androgen receptors). Testosterone itself is correlated with aggressive behavior (Olweus et al, 1988) so with the selection against testosterone due to people who were more altruistic makes sense in this evolutionary context.
Cieri et al argue a good case—that the beginnings of behavioral modernity was due to selection against aggressive behavior, shifted towards pro-sociality. The fact that this began to occur around the Agricultural Revolution is no coincidence, in my opinion.
However, there seems to be a level of testosterone that a civilization needs to remain standing. Testosterone levels have reduced in the past two decades. Men are becoming more feminized, partly due to the environments we have constructed for ourselves. It’s in part due to the foods we eat/what we eat out of that is causing the drop. For instance, imagine being in an environment that destroys human testosterone levels. For instance, let’s say that a lot of the food we eat is made with/stored in a lot of BPA-containing storage. Over time, this would cause differing gene expression. People who are eating these testosterone-lowering foods will have children and, theoretically, pass on the genetically expressed genes to their children, in an epigenetic transference. Since those genes would then be advantageous in the environments we have constructed for ourselves, they would then get selected for. Once enough people get the gene in the population then it will reach fixation. That gene will then get selected in that population. If that gene is one that lowers testosterone, you will then begin to have a more feminized population (like we are seeing now, with men having lower levels of testosterone now than we did twenty years ago).
As I argued in my previous article on testosterone, what Rushton described in his 1988 paper was the Graeco-Roman elite did not breed due to having less circulating testosterone. As I have covered, low testosterone is correlated with having fewer children. As Rushton hypothesized, the elite did not breed while the lower classes did. We can look at it today and look at the ‘elite’ as upper-middle/upper class and look at the lower class, as, well the lower class. We do see the testosterone/class relationship today, with higher classes having lower levels of testosterone, vice versa for lower classes (Dabbs and Morris, 1990).
When looking at testosterone changes over time, fertility rates need to be looked at. Testosterone is down across the board all over the Western hemisphere, and it just so happens that the West is in a fertility crisis (with Europe having the lowest fertility in the world). Not surprisingly, testosterone is taking a dip in the West which is then having a negative effect on testosterone levels. This is due, partly, to the anti-testosterone environments that we have unknowingly (?) constructed for ourselves. To mediate these problems, we need to construct environments that keep testosterone levels raised as to side-step all of the horrible health problems associated with low testosterone, especially later in life.
So, since testosterone is the dominance/confidence/stress hormone, it’s clear that most men don’t put themselves into situations where the hormone would be heightened by the body. Testosterone levels do change throughout the day and depending on events that occur. If you’re around a lot of rowdy people, your testosterone will raise in response to the action around you. Testosterone rises significantly when in large groups and others around are committing violence and being destructive. This is natural, though. When this occurs, you’ll be at the ready for anything that happens, there will be no surprises. It’s a stress hormone, in that it rises mostly in stressful situations.
For society to form, there needed to be somewhat of a testosterone reduction throughout our evolutionary history. This allowed us to trade with each other and so, altruistic behaviors then were selected for. However, too much of a testosterone reduction within single populations leads to lower fertility, and, eventually, the fall of societies due to lower fertility rates. The key here is that we need to construct environments that encourage higher levels of testosterone. If something is not done, then Western society will fall sooner, rather then later (all things eventually come to an end; nothing lasts forever).
Evolution and IQ Linkfest II
1000 words
Why Grit Is More Important Than IQ When You’re Trying To Become Successful (Psychologist Angela Duckworth states that what matter for future life success isn’t IQ, SAT scores, or even graduating from a top college. What matters most for life success is a blend of perseverance and passion that she calls ‘grit’, in her book Grit: The Power of Passion and Perseverance. According to Duckworth, grittiness is passion, and being passionate about something will make you successful is persevering in the face of adversity; i.e., something not working out in your favor and you continue to go at it. She thought of two equations: talent x effort=skill, skill x effort=achievement. Talent is how quickly skills improve when effort is invested, whereas achievement occurs when you take the skills you acquired and put them to use. I’ll buy the book and read it and see what else she says.)
How Skill Expertise Shapes the Brain Functional Architecture: An fMRI Study of Visuo-Spatial and Motor Processing in Professional Racing-Car and Naïve Drivers (Brain functional architecture sustaining visuo-motor processing in racecar drivers “undergoes both ‘quantitative’ and ‘qualitative’ modifications that are evident even when the brain is engaged in relatively simple, non-demanding tasks.” Pretty much, get good at something, like really good, and your brain will change in size and mass.)
Acquiring ‘‘the Knowledge’’ of London’s Layout Drives Structural Brain Changes (Specific and enduring structural brain changes in adults “can be induced by biologically relevant behaviors engaging higher cognitive functions such as spatial memory.” Yet more evidence that becoming an ‘expert’ in something leads to substantial brain changes—which are permanent.)
Autism genes conserved during human evolution to make us smarter, say scientists (We were selected to be autistes since it was beneficial in our ancestral past. Autism is also associated with intellectual achievement.)
A model for brain life history evolution (As adult brain mass increases, so does skill, assumming the costs of maintaining brain mass and memories stay constant. This could be a cause for our larger brains. We know that our brains consume 20 ro 25 percent of our daily kcal, so in our evolutionary past, those who couldn’t amass the kcal to power the ever-growing brain would have died. González-Forero says that as we became proficient with tools, then our brain size began to increase. I have cited a few studies saying that over the past month.)
Lessons from Making Brain Soup (Learn about Herculano-Houzel and Lent’s 2005 Isotropic Fractionator—a machine that allows single cells in ‘brain soup’ to be counted as to get an accurate estimate of neurons.)
Numbers of neurons as biological correlates of cognitive capability (Body mass is a poor predictor of neurons, number of brain stem neurons estimates the capacity for processing bodily signals, mass of the cortex is a poor predictor of neuronal amount, the bird pallium packs more neurons than primate cortices of similar mass and finally the number of neurons in the cortex or pallium correlate directly with intelligence. Herculano-Houzel is blazing a new path in the field of neuroscience, with a novel way of looking at the brain showing that our brains are only scaled-up primate brains in terms of its neuronal composition.)
Creative People Have Better-Connected Brains, Scans Reveal (Highly creative people have more connections on the right and left sides of their brains, suggesting that creativity is biological in nature.)
Genetics Play a Role in Social Anxiety Disorder, Study Finds (Like most disorders, genetics plays a role. Whether it’s small or large, more often than not, genetics will always have at least a bit to say.)
Peer-review activists push psychology journals towards open data (An APA editor will not step down for stating that he won’t publish papers in which the authors don’t let their dataset become public. This is a great move. Why publish something that may possibly be garbage?)
We Look Like Our Names: The Manifestation of Name Stereotypes in Facial Appearance. (This is an interesting one, and one I’ve wondered my whole life since people have told me that ‘I don’t physically look’ how my name is. The researchers state that “facial appearance represents social expectations of how a person with a specific name should look.” Social tags influence one’s facial appearance.)
Greater insight into basic biology of pain will reveal non-addictive remedies (We need to better understand pain physiology, drug development and the individual response to pain in order to develop non-addictive drugs.)
Researchers Discover How Animals Measure Annual Time to Reproduce (The pituitary gland mediates when some mammals start reproducing. The length of the day is noticed in most animals by the pineal gland in the brain.
Does Cannabis Use Lower Your IQ? (No it does not. Recent longitudinal studies show that smoking marijuana does not lead to cognitive decline.
Reader’s Corner: Do we really understand animal intelligence? “Are We Smart Enough to Know How Smart Animals Are?” (We do not understand animal intelligence and we are not smart enough to know how smart animals are. We have an anthropocentric view of evolution, and thusly, we attempt to put our cognitive traits onto other animals when they are adapted for other areas. Herculano-Houzel’s research will begin to detangle this.)
Can Animals Acquire Language? (Evidence says no. However, I’m sure a few readers have heard of Koko the gorilla. She’s able to do sign language and has an estimated IQ of 75 to 95 on the Cattell Infant Intelligence Scale (pg. 99))
Dogs, toddlers show similarities in social intelligence (There is a g factor for dogs. The authors state that the similarities between child and dog intelligence could come down to ‘survival of the friendliest’. I’ll write about this soon.)
How Humans Became Intelligent (Cognitive neuroscientist and philosopher Daniel Dennet sees human consciousness as memetics and genetics. That is, we learn from others and what we are able to learn from others comes down to our genes. I will buy this book as well.)
The Testosterone and Fertility Conundrum: A Western Perspective
2750 words
Some people are scared of testosterone. This is no surprise, since a super-majority of people have no background in the human sciences. I’m sure plenty men know what it’s like to have low testosterone, just like some men know what it’s like to have higher T levels than average. What is the optimum level of testosterone? Why are some people scared of this hormone?
Rushton (1997) posited that r/K Selection Theory could be used to classify the races of Man on a spectrum, going from r-selection (having many children but showing little to no parental care) to K-selection (having fewer children but showing a lot of parental care). He stated that the traits of the races were also on the r/K spectrum, with the races having stark differences in morphology. Rushton’s application of r/K theory to humans isn’t completely wrong, though I do have some problems with some of his claims, such as his claims that the races differ in average penis size. He contends that testosterone is the cause for higher crime rates for black Americans and higher rates of prostate cancer in black Americans compared to white Americans.
However, in 2014, Richard et al showed that when controlling for age, blacks had 2.5 to 4.9 percent more testosterone than whites, on average. This cannot explain racial differences in prostate cancer. However, some people may emphatically claim that the races differ in average testosterone, with blacks having 13 percent higher free testosterone than whites on average. The citation that gets used the most to prove that blacks supposedly have higher testosterone than whites is Ross et al (1986), which is based on a sample of 100 people (50 black, 50 white). He claims that it’s when T levels are higher, so it’s a ‘better study’ even though the sample leaves a lot to be desired. A much more robust study showed that the difference was negligible, and not enough to account for the differential prostate cancer rates between the races.
Rohrmann et al (2007) show that there are no differences in circulating testosterone between blacks and whites in a nationally representative sample of American men. Mexicans had the highest levels. There were, however, B-W differences in estradiol production. They couldn’t confirm the other studies that stated that blacks had higher testosterone, possibly due to variations in age or using non-representative samples (that’s the culprit). Their nationally representative sample showed there was no difference in testosterone between blacks is whites, while the meta-analysis showed by Richard et al (2014) showed the difference was negligible at 2.5 to 4.9 percent higher rate of testosterone which doesn’t explain why blacks have a higher rate of acquiring prostate cancer.
The much more likely culprit for blacks having higher rates of prostate cancer, as I have written about before, are environmental factors. The two main factors are receiving less sunlight and diet. There is no evidence that higher levels of testosterone lead to prostate cancer (Michaud, Billups, and Partin, 2015). Contrary to those who say that higher levels of T cause prostate cancer, there is growing evidence that lower levels of T lead to prostate cancer (Park et al, 2015). Put simply, there is no evidence for testosterone’s supposed impact on the prostate (Stattin et al, 2013).
Differences in androgen/androgen receptors have been explained as a cause for racial differences in prostate cancer (Pettaway, 1999), however, these results haven’t been consistent (Stattin et al, 2003) and these differences in circulating androgen may possibly be explained by differences in obesity between the two populations (Gapstur et al, 2002; also see my posts on obesity and race).
Due to the ‘testosterone scare’, some people may believe that having low T is a ‘good thing’, something that’s preferred over being a high T savage. However, testosterone and the androgen receptor gene polymorphism are both associated with competitiveness and confidence in men (Eisenegger et al, 2016) and a reduced risk of cardiovascular disease in elderly men (Ohlsson et al, 2011). Obviously, lower testosterone is related to less overall confidence. People who have the thought in their head that testosterone is a ‘bad hormone’ will believe the negativity about it in the media and popular headlines.
Testosterone alone does not cause violence, but it does cause men to be socially dominant. Testosterone has been shown to increase in the aggressive phases of sports games and when shown artificial humans made to invoke physiologic responses, leading some researchers to argue that testosterone should be classified as a stress hormone. Testosterone does change based on watching one’s favorite soccer team winning or losing in a sample of 21 men (Bernhardt et al, 1998), lending some credence to the claim that testosterone is and should be classified as a stress hormone. Also of interest is that men who administered high levels of testosterone did not report higher levels of aggression (Batrinos, 2012).
I’ve heard some people literally say that having low testosterone is ‘a good thing’. People say this out of ignorance. There are a whole slew of problems associated with low testosterone, including but not limited to: insulin resistance in diabetic men (Grossmann et al, 2008); metabolic syndrome (Tsuijimura et al, 2013); muscle loss (Yuki et al, 2013); stroke and transient ischemic attack (a mini-stroke; Yeap et al, 2009); associated with elevated risk for dementia in older men (Carcaillon et al, 2014); myocardial infarction (heart attack) in diabetic men (Daka et al, 2015) etc. So it seems that the fear of testosterone from those in the anti-testosterone camp are largely blown out of proportion.
Testosterone is also a ‘food’ for the brain, with low levels being related to mental illness, sexual dysfunction, lower quality of life and cognitive impairment (Moffat et al, 2011) in both sexes (Ciocca et al, 2016). Noticed in both men in women with testosterone deficits were: cognitive impairment (reduction of working memory, episodic memory, processing speed, visual-spatial functioning and executive performance); a decrease in sexual activity; anxiety, schizophrenia, depression and stress; and alterations in cortical thickness in the brain. The fact that testosterone is so heavily important to the body’s central functioning is extremely clear. This is why it’s laughable that some people would be happy and brag about having low testosterone.
I recently came across a book called The Testosterone Hypothesis: How Hormones Regulate the Life Cycles of Civilization. Barzilai’s main premise is that the rise and fall of the West is mediated by the hormone testosterone, and due to lower testosterone levels this is one large reason for what is currently occurring in the West. The book has an extremely interesting premise. Barzilai’s hypothesis does line up with the declining levels of testosterone in America (Travison et al, 2007) though other research shows no decline in American testosterone levels from the years 88-91 to 99-04 (Nyante et al, 2007). Moreover, men who had higher level of n-6 in their blood then n-3 were far more likely to be infertile (Safarinejad et al, 2010) a marker of low testosterone (Sharpe, 2012). The ratio of n-6 to n-3 from the years 1935 to 1939 were 8.4 to 1, whereas from the years 1935 to 1985, the ratio increased to about 10 percent (Raper et al, 1992). The ratio of n-6 to n-3, on top of lowering sperm count (which is correlated with testosterone) also has negative effects on male and female cognitive ability (Lassek and Gaulin, 2011).
Barzilai’s research also corroborates Rushton’s (1986) theory of why there are lower birthrates for Europeans around the world. Rushton stated that this cycle has been noticed throughout history, with empires rising and falling due to differential birthrates between the ruling class and the ruled. Rushton also hypothesized that the cultures and gene pools associated with the Graeco-Roman empire were “evolutionary dead ends” (Rushton, 1986: 148). Knowing what we now know about the relationship between cognitive ability, testosterone, and fertility, we now have a plausible hypothesis for Rushton’s hypothesis and one of the (many) reasons why the Graeco-Roman empire collapsed. Rushton further hypothesized that the cause for lower fertility in European populations “may be partly mediated by a psychological process in which the desire to be in control of both oneself and one’s environment is taken to an extreme.” Of course there’s a good chance that this psychological process is mediated/influenced by testosterone.
Europe is the continent with the lowest fertility (ESHRE Capri Workshop Group, 2010). Testosterone has declined in Europe as a whole (Rivas et al, 2014), and this is a strong cause for the lower birthrates in Europe (along with genetic reasons) and in Finland (Perheentupa et al, 2013). The introduction of Westernized diets lowers testosterone, so this is no surprise that a reduction is seen in countries that begin to consume a Western diet. Another probable cause for lower testosterone/fertility in Europe at the moment is the large number of European men that died in WWI and WWII. Those that were more willing to fight died, meaning there was less of a chance he spread his genes. So, over time, this lead to the current cucking of Europe that we are now witnessing.
Testosterone is also hypothesized to have driven evolution (Howard, 2001). Testosterone is such an important part of human evolution and development, so much so that if we had a lower level of the hormone all throughout our evolution that we would be a different species today. Testosterone is needed for sexual functioning, good mental and brain health, fertility, cognitive ability, muscle mass retention in both young and old men, etc. Testosterone is one of the most important hormones for both men and women, and low levels for both sexes are detrimental to a high quality of life. The current data on testosterone and prostate cancer shows that higher levels of testosterone don’t contribute to prostate cancer. Testosterone, then, also isn’t a cause for the racial gap in prostate cancer because other environmental factors better explain it. If people really are happy about having lower testosterone, then I hope they have fun living a life with a low sex drive, lower cognition in old age, lower muscle mass and a higher chance of stroke and metabolic syndrome.
One of the most interesting things about testosterone is the possibility that it explains why civilizations rise and fall. There is anecdotal evidence from Rushton, as well as his theorizing that the higher classes in Rome didn’t breed which led to their downfall. We now know that lower fertility rates for men are associated with lower testosterone, so along with Barzilai’s thesis of testosterone causing the rise and fall of civilizations, Rushton’s theorizing of the cause of lower European fertility and the cause of the fall of the Graeco-Roman empire.
Testosterone is an extremely important hormone, one that drives human evolution and society formation since it’s associated with dominance and confidence. Low testosterone is looked at as ‘good’ because those with higher intelligence have lower levels of the hormone (indicated by lower confidence and having sex at a later age). I showed that the higher IQ East Asian men have a problem finding dates and being looked at as sexually attractive (even though they rated themselves as average). Along with lower East Asian fertility, specifically in Japan, does it seem to you like the high IQ people are more desired if they are having problems keeping their birthrates up? The fact of the matter is, lower levels of testosterone are correlated with lower levels of fertility. If men don’t have as much testosterone pumping through their veins, they will be less likely to have sex and thusly reproduce.
References
Batrinos, M. L. (2012). Testosterone and aggressive behavior in man. International Journal of Endocrinology & Metabolism,10(3), 563-568. doi:10.5812/ijem.3661
Bernhardt, P. C., Jr, J. M., Fielden, J. A., & Lutter, C. D. (1998). Testosterone changes during vicarious experiences of winning and losing among fans at sporting events. Physiology & Behavior,65(1), 59-62. doi:10.1016/s0031-9384(98)00147-4
Carcaillon, L., Brailly-Tabard, S., Ancelin, M., Tzourio, C., Foubert-Samier, A., Dartigues, J., . . . Scarabin, P. (2014). Low testosterone and the risk of dementia in elderly men: Impact of age and education. Alzheimer’s & Dementia,10(5). doi:10.1016/j.jalz.2013.06.006
Ciocca G, Limoncin E, Gravina GL, et al. Is testosterone a food for brain? Sex Med Rev 2016;4:15-25.
Daka, B., Langer, R. D., Larsson, C. A., Rosén, T., Jansson, P. A., Råstam, L., & Lindblad, U. (2015). Low concentrations of serum testosterone predict acute myocardial infarction in men with type 2 diabetes mellitus. BMC Endocrine Disorders,15(1). doi:10.1186/s12902-015-0034-1
Eisenegger, C., Kumsta, R., Naef, M., Gromoll, J., & Heinrichs, M. (2016). Testosterone and androgen receptor gene polymorphism are associated with confidence and competitiveness in men. Hormones and Behavior. doi:10.1016/j.yhbeh.2016.09.011
, , , , , . Serum androgen concentrations in young men: a longitudinal analysis of associations with age, obesity, and race—the CARDIA male hormone study. Cancer Epidemiol Biomarkers Prev 2002; 11: 1041–7
Grossmann, M., Thomas, M. C., Panagiotopoulos, S., Sharpe, K., Macisaac, R. J., Clarke, S., . . . Jerums, G. (2008). Low Testosterone Levels Are Common and Associated with Insulin Resistance in Men with Diabetes. The Journal of Clinical Endocrinology & Metabolism,93(5), 1834-1840. doi:10.1210/jc.2007-2177
Howard JM (2001): Androgens in human evolution. A new explanation of human evolution.
Lassek, W. D., & Gaulin, S. J. (2011). Sex Differences in the Relationship of Dietary Fatty Acids to Cognitive Measures in American Children. Frontiers in Evolutionary Neuroscience,3. doi:10.3389/fnevo.2011.00005
Michaud, J. E., Billups, K. L., & Partin, A. W. (2015). Testosterone and prostate cancer: an evidence-based review of pathogenesis and oncologic risk. Therapeutic Advances in Urology,7(6), 378-387. doi:10.1177/1756287215597633
Moffat, S. D., Zonderman, A. B., Metter, E. J., Blackman, M. R., Harman, S. M., & Resnick, S. M. (2002). Longitudinal Assessment of Serum Free Testosterone Concentration Predicts Memory Performance and Cognitive Status in Elderly Men. The Journal of Clinical Endocrinology & Metabolism,87(11), 5001-5007. doi:10.1210/jc.2002-020419
Nyante, S. J., Graubard, B. I., Li, Y., Mcquillan, G. M., Platz, E. A., Rohrmann, S., . . . Mcglynn, K. A. (2011). Trends in sex hormone concentrations in US males: 1988-1991 to 1999-2004. International Journal of Andrology,35(3), 456-466. doi:10.1111/j.1365-2605.2011.01230.x
Ohlsson C, Barrett-Connor E, Bhasin S, et al. High serum testosterone is associated with reduced risk of cardiovascular events in elderly men: the MrOS (Osteoporotic Fractures in Men) study in Sweden. J Am Coll Cardiol. 2011; 58(16):1674-1681.
Park, J., Cho, S. Y., Jeong, S., Lee, S. B., Son, H., & Jeong, H. (2015). Low testosterone level is an independent risk factor for high-grade prostate cancer detection at biopsy. BJU International,118(2), 230-235. doi:10.1111/bju.13206
Perheentupa, A., Makinen, J., Laatikainen, T., Vierula, M., Skakkebaek, N. E., Andersson, A., & Toppari, J. (2012). A cohort effect on serum testosterone levels in Finnish men. European Journal of Endocrinology,168(2), 227-233. doi:10.1530/eje-12-0288
Pettaway CA. Racial differences in the androgen/androgen receptor pathway in prostate cancer. J Natl Med Assoc 1999, 91: 653:650
Raper, N. R., Cronin, F. J., & Exler, J. (1992). Omega-3 fatty acid content of the US food supply. Journal of the American College of Nutrition,11(3), 304-308. doi:10.1080/07315724.1992.10718231
Richard, A., Rohrmann, S., Zhang, L., Eichholzer, M., Basaria, S., Selvin, E., . . . Platz, E. A. (2014). Racial variation in sex steroid hormone concentration in black and white men: a meta-analysis. Andrology,2(3), 428-435. doi:10.1111/j.2047-2927.2014.00206.x
Rivas AM, Mulkey Z, Lado-Abeal J, Yarbrough S. Diagnosing and managing low serum testosterone. Proc (Bayl Univ Med Cent) 2014;27:321-324
Rohrmann, S., Nelson, W. G., Rifai, N., Brown, T. R., Dobs, A., Kanarek, N., . . . Platz, E. A. (2007). Serum Estrogen, But Not Testosterone, Levels Differ between Black and White Men in a Nationally Representative Sample of Americans. The Journal of Clinical Endocrinology & Metabolism,92(7), 2519-2525. doi:10.1210/jc.2007-0028
Ross R, Bernstein L, Judd H, Hanisch R, Pike M, Henderson B. Serum testosterone levels in healthy young black and white men. J Natl Cancer Inst. 1986 Jan;76(1):45–48
Rushton, J. P. (1986). Gene-Culture Coevolution and Genetic Similarity Theory: Implications for Ideology, Ethnic Nepotism, and Geopolitics. Politics and the Life Sciences,4(02), 144-148. doi:10.1017/s0730938400004706
Rushton J P (1997). Race, Evolution, and Behavior. A Life History Perspective (Transaction, New Brunswick, London).
Safarinejad, M. R., Hosseini, S. Y., Dadkhah, F., & Asgari, M. A. (2010). Relationship of omega-3 and omega-6 fatty acids with semen characteristics, and anti-oxidant status of seminal plasma: A comparison between fertile and infertile men. Clinical Nutrition,29(1), 100-105. doi:10.1016/j.clnu.2009.07.008
Sharpe, R. M. (2012). Sperm counts and fertility in men: a rocky road ahead. EMBO reports,13(5), 398-403. doi:10.1038/embor.2012.50
Stattin, P., Lumme, S., Tenkanen, L., Alfthan, H., Jellum, E., Hallmans, G., . . . Hakama, M. (2003). High levels of circulating testosterone are not associated with increased prostate cancer risk: A pooled prospective study. International Journal of Cancer,108(3), 418-424. doi:10.1002/ijc.11572
Travison, T. G., Araujo, A. B., O’Donnell, A. B., Kupelian, V., & Mckinlay, J. B. (2007). A Population-Level Decline in Serum Testosterone Levels in American Men. The Journal of Clinical Endocrinology & Metabolism,92(1), 196-202. doi:10.1210/jc.2006-1375
Tsujimura, A., Miyagawa, Y., Takezawa, K., Okuda, H., Fukuhara, S., Kiuchi, H., . . . Nonomura, N. (2013). Is Low Testosterone Concentration a Risk Factor for Metabolic Syndrome in Healthy Middle-aged Men? Urology,82(4), 814-819. doi:10.1016/j.urology.2013.06.023
Yeap, B. B., Hyde, Z., Almeida, O. P., Norman, P. E., Chubb, S. A., Jamrozik, K., . . . Hankey, G. J. (2009). Lower Testosterone Levels Predict Incident Stroke and Transient Ischemic Attack in Older Men. Endocrine Reviews,30(4), 411-411. doi:10.1210/edrv.30.4.9994
Yuki, A., Otsuka, R., Kozakai, R., Kitamura, I., Okura, T., Ando, F., & Shimokata, H. (2013). Relationship between Low Free Testosterone Levels and Loss of Muscle Mass. Scientific Reports,3. doi:10.1038/srep01818
Heritability, the Grandeur of Life, and My First Linkfest on Human Evolution and IQ
1100 words
Benjamin Steele finally replied to my critique of his ‘strong evidence and argument’ on race, IQ and adoption. He goes on to throw baseless ad hominem attacks as well as appealing to motive (assuming my motivation for being a race realist; assuming that I’m a ‘racist’, whatever that means). When I do address his ‘criticisms’ of my response to him, I will not address his idiotic attacks as they are a waste of time. He does, however, say that I do not understand heritability. I understand that the term ‘heritable’ doesn’t mean ‘genetic’. I understand that heritability is the proportion of phenotypic variance attributed to genetic variance. I do not believe that heritability means a trait is X percent genetic. 80 percent of the variation in the B-W IQ gap is genetic, with 20 percent explained by environmental effects. Note that I’m not claiming that heritable means genetic. All that aside, half of his reply to me is full of idiotic, baseless and untrue accusations which I will not respond to. So, Mr. Steele, if you do decide to reply to my response to you this weekend, please leave the idiocy at the door. Anyway, I will tackle that this weekend. Quick note for Mr. Steele (in case he reads this): if you don’t believe me about the National Crime and Victimization Survey showing that police arrest FEWER blacks than are reported by the NCVS, you can look it up yourself, ya know.
I’m beginning to understand why people become environmentalists. I’ve recently become obsessed with evolution. Not only of Man, but of all of the species in the world. Really thinking about the grandeur of life and evolution and what leads to the grand diversity of life really had me thinking one day. It took billions of years for us to get to the point we did today. So, why should we continue to destroy environments, displacing species and eventually leading them to extinction? I’m not saying that I fully hold this view yet, it’s just been on my mind lately. Once a species is extinct, that’s it, it’s gone forever. So shouldn’t we do all we possibly can to preserve the wonder of life that took so long to get to the point that we did today?
Some interesting articles to read:
Study: IQ of firstborns differ from siblings (This is some nice evidence for Lassek and Gaulin’s theory stating why first-born children have higher IQs than their siblings: they get first dibs on the gluteofemoral fat deposits that are loaded with n-3 fatty acids, aiding in brain size and IQ.)
Why attitude is more important than IQ (Psychologist Carol Dweck states that attitude is more important than IQ and that attitudes come in one of two types: a fixed mindset or a growth mindset. Those with a fixed mindset believe ‘you are who you are’ and nothing can change it while those with a growth mindset believe they can improve with effort. Interesting article, I will find the paper and comment on it when I read it.)
Positively Arguing IQ Determinism And Effect Of Education (Intelligent people search for intellectually stimulating things whereas less intelligent people do not. This, eventually, will lead to the construction of environments based on that genotype.)
A scientist’s new theory: Religion was key to humans’ social evolution (Nicholas Wade pretty much argues the same in his book The Faith Instinct: How Religion Evolved and Why It Endures. It is interesting to note that archaeologists have discovered what looks to be the beginnings of religiousity around 10kya, coinciding with the agrigultural revolution. I will look into this in the future.)
Galápagos giant tortoises show that in evolution, slow and steady gets you places (Interesting read, on tortoise migration)
Will Mars Colonists Evolve Into This New Kind of Human? (Very interesting and I hope to see more articles like this in the future. Of course, due to being a smaller population, evolution will occur faster due to differing selection pressures. Smaller populations incur more mutations at a faster rate than larger populatons. Will our skin turn a reddish tint? Bone density will decline leading to heavier bones. The need for C-sections due to heavier bones will lead to futher brain size increases. This is also going on on Earth at the moment, as I have previously discussed. Of course differences in culture and technology will lead the colonizers down different paths. I hope I am alive to see the first colonies on Mars and the types of long-term effects of the evolution of Man on the Red Planet.)
Evolution debate: Are humans continuing to evolve? (Of course we are)
Did seaweed make us who we are today? (Seaweed has many important vitamins and minerals that are imperative for brain development and growth—most importantly, it has poly-unsaturated fatty acids (PUFAs) and B12. We are only able to acquire these fatty acids through our diet—our body cannot synthesize the fatty acid on its own. This is just growing evidence for how important it is to have a good ratio of n-3 to n-6.)
Desert people evolve to drink water poisoned with deadly arsenic (More evidence for rapid evolution in human populations. AS3MT is known to improve arsonic metabolism in Chile and Argentina. Clearly, those who can handle the water breed/don’t die while those who cannot succumb to the effects of arsenic poisoning. Obviously, over time, this SNP will be selected for more and more while those who cannot metabolize the arsonic do not pass on their genes. This is a great article to show to anti-human-evolution deniers.)
Here Are the Weird Ways Humans Are Evolving Right Now (CRISPR and gene editing, promotion of obesity through environmental factors (our animals have also gotten fatter, probably due to the feed we give them…), autism as an adaptation (though our definition for autism has relaxed in the past decade). Human evolution is ongoing and never stops, even for Africans. I’ve seen some people claim that since they never left the continent that they are ‘behind in evolution’, yet evolution is an ongoing process and never stops, cultural ‘evolution’ (change) leading to more differences.)
‘Goldilocks’ genes that tell the tale of human evolution hold clues to variety of diseases (We really need to start looking at modern-day diseases through an evolutionary perspective, such as obesity, to better understand why these ailments inflict us and how to better treat our diseases of civilization.)
Understanding Human Evolution: Common Misconceptions About The Scientific Theory (Don’t make these misconceptions about evolution. Always keep up to date on the newest findings.)
Restore Western Civilization ( Enough said. As usual, gold from Brett Stevens. Amerika.org should be one of the first sites you check every day.)
I guess this was my first linkfest (ala hbd chick). I will post one a week.
NotPoliticallyCorrect 