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Research into neural plasticity has been fruitful the past few decades. However, people like Steven Pinker in his book The Blank Slate attempt to undermine the effects of neural plasticity in regards to TBI and IQ, for instance. However, the plasticity of our brains is how our brains evolved (Skoyles and Sagan, 2002). So since our brains are so plastic, then doing certain tasks may help in terms of ‘processing speed’, reaction time and overall cognitive ability, right?
Science Daily reported on a new meta-analysis that took 15 years to complete that looked at how action video games affect reaction time and cognitive performance. What they found was something that I have talked about a bit: that playing these types of games increases one’s reaction time and even their cognitive ability. Unfortunately, the paper is not on Sci-Hub yet, but when it is released on Sci-Hub I will go more in depth on it.
The authors (Benoit et al, 2017) looked at 15 years of papers on action video games and cognitive performance from the year 2000-2015. They focused on war and shooting video games to gauge whether or not there was a causal effect on action video game playing and cognitive performance. They got two meta-analyses out of all of the research they did.
They studied 8,790 people between the ages of 6-40 and gave them a battery of cognitive tests. These tests included spatial attention tasks as well as testing how well one could multi-task while changing their plans in-line with the rules of the game. “It was found that the cognition of gamers was better by one-half of a standard deviation compared to non-gamers.” Though this meta-analysis failed to answer one question: do people who play games have higher cognitive ability or do people with higher cognitive ability play more games? The classic chicken-and-the-egg problem.
They then looked at other studies of 2,883 individuals and partitioned them into 2 groups: groups of people who played action games like war and shooter games whereas the second group played games like SIMS, Tetris and Puzzle (I would loosely term these strategy games as well). They found that both groups played for 8 hours per week, netting 50 hours of gameplay over 12 weeks.
What they found was that the results were overwhelmingly in favor of war and shooting games improving cognition. The interesting thing about these analyses was that it took years to get the data and it is from all over the world, so it doesn’t only hold in America, for instance. Though, in the abstract of the paper (all I have access to at the moment) Benoit et al (2017) write:
Publication bias remains, however, a threat with average effects in the published literature estimated to be 30% larger than in the full literature. As a result, we encourage the field to conduct larger cohort studies and more intervention studies, especially those with more than 30 hours of training.
This is in-line with numerous other papers on the matter of cognitive abilities and action video games. Green and Bavelier (2007) showed that video game players “could tolerate smaller target-distractor distances” whereas “similar effects were observed in non-video-game players who were trained on an action video game; this result verifies a causative relationship between video-game play and augmented spatial resolution.” They found that action video games ‘sharpened vision’ by up to 20 percent. Green and Bavelier (2012) also show that playing action video games may enhance the ability to learn new tasks and that what is learned from playing these types of games “transfers well beyond the training task.”
Green and Bavelier (2003) show that playing action video games showed better visual attention in comparison to those who did not play games. Even those who did not game saw improvement in visual attention which, again, shows that video games have an actual causal effect on these phenomena and it’s not just ‘people with higher cognitive ability choosing to play video games’. (See also Murphy and Spencer, 2009 who show that “There were no other group differences for any task suggesting a limited role for video game playing in the modification of visual attention.“)
Dye, Green, and Bavelier (2009) show that action video games increase reaction time (RT). Variables like videogame-playing when testing cognitive abilities are a huge confound, as can be seen, since people who play action video games have a quicker reaction time than those who do not—which, as I’ve shown, has a causal relationship with game playing since even the controls who did not play action games saw an increase in their RT. Achtman, Green, and Bavelier (2008) show yet again that action video game playing enhances visual attention and overall visual processing.
Green (2008: iii-iv) in an unpublished doctoral dissertation (the first link on Google should be the dissertation) showed the video game players “acquire sensory information more rapidly than NVGPs [non-videogame players]”.
Applebaum et al (2013) showed that action game playing “may be related to enhancements in the initial sensitivity to visual stimuli, but not to a greater retention of information in iconic memory buffers.” Bejjanki et al (2014) show that action video game playing “establish[es] … the development of enhanced perceptual templates following action game play.” Cardoso-Leite and Bavelier (2014) show that video games enhance “behavior in domains as varied as perception, attention, task switching, or mental rotation.”
Boot, Blakely, and Simons (2011) show that there may be a ‘file-drawer effect’ (publication bias)in terms of action video games increasing cognition, which Benoit et al (2017) acknowledge and push for more open studies.
Unsworth et al (2015) state that “nearly all of the relations between video-game experience and cognitive abilities were near zero.” So, there are numerous studies both for and against this (most of the studies for this being done by Green and Bavelier), and so this meta-analysis done by Benoit et al (2017) may finally begin to answer the question: Does playing action video games increase cognitive ability, increase visual attention and increase reaction time? The results of this new meta-analysis suggest yes, and it may have implications for IQ testing.
Richardson and Norgate (2014) in their paper Does IQ Really Predict Job Performance? state that there are numerous other reasons why some individuals may have slower RTs, one of the variables being action video game playing, along with anxiety, motivation, and familiarity with the equipment used, meaning that if one is experienced in video game playing—action games specifically—it may cause differences between individuals that do not come down to ‘processing speed’ or native ability, as is usually claimed (and with such low correlations of .2-.3 for reaction time and IQ, other factors must mediate the relationship that are not genetic in nature).
Now, let’s say the effect is as large as Benoit et al (2017) say it is at one-third of a SD. Would this mean that one would need to attempt to control for video game playing while testing, say, IQ or RT? I believe the answer is definitely pointing in that direction because it is clear—with the mounting evidence—that action video games can reduce RT and thusly confound certain tests. Action video game playing may be a pretty large confound in terms of the outcomes of IQ tests if these new meta-analyses from Benoit et al (2017) hold up. If this does hold up and playing action video games does affect both RT and cognitive ability at one-third of an SD (about 5 points), then the case can be made that this must be controlled for due to confounding the relationship.
In sum, if these effects from this new meta-analysis hold and can be replicated by other studies, then that’s a whole other variable that needs to be accounted for when testing IQ and RT. RT is a complicated variable and, according to Khodaddi et al (2014) “The relationship between reaction time and IQ is too complicated and revealing a significant correlation depends on various variables (e.g. methodology, data analysis, instrument etc.).” This, is in my view, one reason why RT should be tossed out as a ‘predictor of g‘ (whatever that is), as it is not a reliable measure and does not ‘test’ what it is purported to test.
The New York Times published an article on December the 8th titled What Doctors Should Ignore: Science has revealed how arbitrary racial categories are. Perhaps medicine will abandon them, too. It is an interesting article and while I do not agree with all of it, I do agree with some.
It starts off by talking about sickle cell anemia (SCA) and how was once thought of as a ‘black disease’ because blacks were, it seemed, the only ones who were getting the disease. I recall back in high-school having a Sicilian friend who said he ‘was black’ because Sicilians can get SCA which is ‘a black disease’, and this indicates ‘black genes’. However, when I grew up and actually learned a bit about race I learned that it was much more nuanced than that and that whether or not a population has SCA is not based on race, but is based on the climate/environment of the area which would breed mosquitoes which carry malaria. SCA still, to this day, remains a selective factor in the evolution of humans; malaria selects for the sickle cell trait (Elguero et al, 2015).
This is a good point brought up by the article: the assumption that SCA was a ‘black disease’ had us look over numerous non-blacks who had the sickle cell trait and could get the help they needed, when they were overlooked due to their race with the assumption that they did not have this so-called ‘black disease’. Though it is understandable why it got labeled ‘a black disease’; malaria is more prevalent near to the equator and people whose ancestors evolved there are more likely to carry the trait. In regards to SCA, it should be known that blacks are more likely to get SCA, but just because someone is black does not automatically mean that it is a foregone conclusion that one has the disease.
The article then goes on to state that the push to excise race from medicine may undermine a ‘social justice concept’: that is, the want to rid the medical establishment of so-called ‘unconscious bias’ that doctors have when dealing with minorities. Of course, I will not discount that this doesn’t have some effect—however small—on racial health disparities but I do not believe that the scope of the matter is as large as it is claimed to be. This is now causing medical professionals to integrate ‘unconscious bias training’, in the hopes of ridding doctors of bias—whether conscious or not—in the hopes to ameliorate racial health disparities. Maybe it will work, maybe it will not, but what I do know is that if you know someone’s race, you can use it as a roadmap to what diseases they may or may not have, what they may or may not be susceptible to and so on. Of course, only relying on one’s race as a single data point when you’re assessing someone’s possible health risks makes no sense at all.
The author then goes on to write that the terms ‘Negroid, Caucasoid, and Mongoloid’ were revealed as ‘arbitrary’ by modern genetic science. I wouldn’t say that; I would say, though, that modern genetic science has shown us the true extent of human variation, while also showing that humans cluster into 5 distinct geographic categories, which we can call ‘race’ (Rosenberg et al, 2002; but see Wills, 2017 for alternative view that the clusters identified by Rosenberg et al, 2002 are not races. I will cover this in the future). The author then, of course, goes on to use the continuum fallacy stating that since “there are few sharp divides where one set of traits ends and another begins“. A basic rebuttal would be, can you point out where red and orange are distinct? How about violet and blue? Blue and Cyan? Yellow and orange? When people commit the continuum fallacy then the only logical conclusion is that if races don’t exist because there are “few sharp divides where one set of traits ends and another begins“, then, logically speaking, colors don’t exist either because there are ‘few [if any] sharp divides‘ where one color ends and another begins.
The author also cites geneticist Sarah Tishkoff who states that the human species is too young to have races as we define them. This is not true, as I have covered numerous times. The author then cites this study (Ng et al, 2008) in which Craig Venter’s genome was matched with the (in)famous [I love Watson] James Watson and focused on six genes that had to do with how people respond to antipsychotics, antidepressants, and other drugs. It was discovered that Venter had two of the ‘Caucasian’ variants whereas Watson carried variants more common in East Asians. Watson would have gotten the wrong medicine based on the assumption of his race and not on the predictive power of his own personal genome.
The author then talks about kidney disease and the fact that blacks are more likely to have it (Martins, Agodoa, and Norris, 2012). It was assumed that environmental factors caused the disparity of kidney disease in blacks when compared to whites, however then the APOL1 gene variant was discovered, which is related to worse kidney outcomes and is in higher frequencies in black Americans, even in blacks with well-controlled blood pressure (BP) (Parsa et al, 2013). The author then discusses that black kidneys were seen as ‘more prone to failure’ than white kidneys, but this is, so it’s said, due to that one specific gene variant and so, race shouldn’t be looked at in regards to kidney disease but individual genetic variation.
In one aspect of the medical community can using medicine based on one’s race help: prostate cancer. Black men are more likely to be afflicted with prostate cancer in comparison to whites (Odedina et al, 2009; Bhardwaj et al, 2017) with it even being proposed that black men should get separate prostate screenings to save more lives (Shenoy et al, 2016). Then he writes that we still don’t know the genes responsible, however, I have argued in the past that diet explains a large amount—if not all of the variance. (It’s not testosterone that causes it like Ross et al, 1986 believe).
The author then discusses another medical professional who argues that racial health disparities come down to the social environment. Things like BP could—most definitely—be driven by the social environment. It is assumed that the darker one’s skin is, the higher chance they have to have high BP—though this is not the case for Africans in Africa so this is clearly an American-only problem. I could conjure up one explanation: the darker the individual, the more likely he is to believe he is being ‘pre-judged’ which then affects his state of mind and has his BP rise. I discussed this shortly in my previous article Black-White Differences in Physiology. Williams (1992) reviewed evidence that social, not genetic, factors are responsible for BP differences between blacks and whites. He reviews one study showing that BP is higher in lower SES, darker-skinned blacks in comparison to higher SES blacks whereas for blacks with higher SES no effect was noticed (Klag et al, 1991). Sweet et al (2007) showed that for lighter-skinned blacks, as SES rose BP decreased while for darker-skinned blacks BP increased as SES did while implicating factors like ‘racism’ as the ultimate causes.
There is evidence for the effect of psychosocial factors and BP (Marmot, 1985). In a 2014 review of the literature, Cuffee et al (2014) identify less sleep—along with other psychosocial factors—as another cause of higher BP. It just so happens that blacks average about one hour of sleep less than whites. This could cause a lot of the variation in BP differences between the races, so clearly in the case of this variable, it is useful to know one’s race, along with their SES. Keep in mind that any actual ‘racism’ doesn’t have to occur; the person only ‘needs to perceive it’, and their blood BP will rise in response to the perceived ‘racism’ (Krieger and Sidney, 1996). Harburg et al (1978) write in regards to Detroit blacks:
For 35 blacks whose fathers were from the West Indies, pressures were higher than those with American-born fathers. These findings suggest that varied gene mixtures may be related to blood pressure levels and that skin color, an indicator of possible metabolic significance, combines with socially induced stress to induce higher blood pressures in lower class American blacks.
Langford (1981) shows that when SES differences are taken into account that the black-white BP disparity vanishes. So there seems to be good evidence for the hypothesis that psychosocial factors, sleep deprivation, diet and ‘perceived discrimination’ (whether real or imagined) can explain a lot of this gap so race and SES need to be looked at when BP is taken into account. These things are easily changeable; educate people on good diets, teach people that, in most cases, no, people are not being ‘racist’ against you. That’s really what it is. This effect holds more for darker-skinned, lower-class blacks. And while I don’t deny a small part of this could be due to genetic factors, the physiology of the heart and how BP is regulated by even perceptions is pretty powerful and could have a lot of explanatory power for numerous physiological differences between races and ethnic groups.
Krieger (1990) states that in black women—not in white women—“internalized response to unfair treatment, plus non-reporting of race and gender discrimination, may constitute risk factors for high blood pressure among black women“. This could come into play in regards to black-white female differences in BP. Thomson and Lip (2005) show that “environmental influence and psychosocial factors may play a more important role than is widely accepted” in hypertension but “There remain many uncertainties to the relative importance and contribution of environmental versus genetic influences on the development of blood pressure – there is more than likely an influence from both. However, there is now evidence to necessitate increased attention in examining the non-genetic influences on blood pressure …” With how our physiology evolved to respond to environmental stimuli and respond in real time to perceived threats, it is no wonder that these types of ‘perceived discrimination’ causes higher BP in certain groups with lower SES.
Wilson (1988) implicates salt as the reason why blacks have higher BP than whites. High salt intake could affect the body’s metabolism by causing salt retention which influences blood plasma volume, cardiac output. However, whites have a higher salt intake than blacks, but blacks still ate twice the recommended amounts from the dietary guidelines (all ethnic subgroups they analyzed from America over-consumed salt as well) (Fulgoni et al, 2014). Blacks are also more ‘salt-sensitive’ than whites (Sowers et al 1988; Schmidlin et al, 2009; Sanada, Jones, and Jose, 2014) which is also heritable in blacks (Svetke, McKeown, and Wilson, 1996). A slavery hypothesis does exist to explain higher rates of hypertension in blacks, citing salt deficiency in the parts of Africa that supplied the slaves to the Americas, to the trauma of the slave trade and slavery in America. However, historical evidence does not show this to be the case because “There is no evidence that diet or the resulting patterns of disease and demography among slaves in the American South were significantly different from those of other poor southerners” (Curtin, 1992) whereas Campese (1996) hypothesizes that blacks are more likely to get hypertension because they evolved in an area with low salt.
The NYT article concludes:
Science seeks to categorize nature, to sort it into discrete groupings to better understand it. That is one way to comprehend the race concept: as an honest scientific attempt to understand human variation. The problem is, the concept is imprecise. It has repeatedly slid toward pseudoscience and has become a major divider of humanity. Now, at a time when we desperately need ways to come together, there are scientists — intellectual descendants of the very people who helped give us the race concept — who want to retire it.
Race is a useful concept. Whether in medicine, population genetics, psychology, evolution, physiology, etc it can elucidate a lot of causes for differences between races and ethnic groups—whether or not they are genetic or psychosocial in nature. That just attests to both the power of suggestion along with psychosocial factors in regards to racial differences in physiological factors.
Finally let’s see what the literature says about race in medicine. Bonham et al (2009) showed that both black and white doctors concluded that race is medically relevant but couldn’t decide why however they did state that genetics did not explain most of the disparity in relation to race and disease aside from the obvious disorders like Tay Sachs and sickle cell anemia. Philosophers accept the usefulness of race in the biomedical sciences (Andreason, 2009; Efstathiou, 2012; Hardimon, 2013; Winther, Millstein, and Nielsen, 2015; Hardimon, 2017) whereas Risch et al (2002) and Tang et al (2002) concur that race is useful in the biomedical sciences. (See also Dorothy Roberts’ Ted Talk The problem with race-based medicine which I will cover in the future). Richard Lewontin, naturally, has hang-ups here but his contentions are taken care of above. Even if race were a ‘social construct‘, as Lewontin says, it would still be useful in a biomedical sense; but since there are differences between races/ethnic groups then they most definitely are useful in a biomedical sense, even if at the end of the day individual variation matters more than racial variation. Just knowing someone’s race and SES, for instance, can tell you a lot about possible maladies they may have, even if, utltimately, individual differences in physiology and anatomy matter more in regards to the biomedical context.
In conclusion, race is most definitely a useful concept in medicine, whether race is a ‘social construct’ or not. Just using Michael Hardimon’s race concepts, for instance, shows that race is extremely useful in the biomedical context, despite what naysayers may say. Yes, individual differences in anatomy and physiology trump racial differences, but just knowing a few things like race and SES can tell a lot about a particular person, for instance with blood pressure, resting metabolic rate, and so on. Denying that race is a useful concept in the biomedical sciences will lead to more—not less—racial health disparities, which is ironic because that’s exactly what race-deniers do not want. They will have to accept a race concept, and they would accept Hardimon’s socialrace concept because that still allows it to be a ‘social construct’ while acknowledging that race and psychosocial factors interact to cause higher physiological variables. Race is a useful concept in medicine, and if the medical establishment wants to save more lives and actually end the racial disparities in health then they should acknowledge the reality of race.
Many long-time readers may know of the numerous tirades of been on in regards to the “testosterone causes crime and aggression” myth. It’s a fun subject to talk about because the intelligent human physiological system is an amazing system. However, people who are not privy to the literature on testosterone in regards to race, aggression, crime, sex differences etc are only aware of whatever they read in pop science articles. So since they never read the actual papers themselves, they get a clouded view of a subject.
In my last article, I wrote about how there are no “testosterone genes”. In previous articles on the hormone, I have proven that there is no causal link between testosterone and aggression. But when comparing the sexes, how do the results look? Do they look the same with men being more violent while women—who have substantially less testosterone than men—do not have any higher levels of aggression or crime? The most recent study I’m aware of is by Assari, Caldwell, and Zimmerman (2014) titled: Sex Differences in the Association Between Testosterone and Violent Behaviors.
To make a long story short, there was no relationship between testosterone and aggression in men, but a significant relationship between testosterone and aggression in women. This data comes from the Flint Adolescent Study, a longitudinal study conducted between the years of 1994 to 2012. In regards to testosterone collection, saliva was used which has a perfect correlation with circulating testosterone. The eligibility to be included in the testosterone assay was “provided consent for the procedure, not being pregnant, not having anything to eat, drinking nothing except water, and not using tobacco, 1 hour prior to collection” (Assari, Caldwell, and Zimmerman, 2014).
The adolescent who contributed saliva gave a whole slew of demographic factors including SES, demographics, psychological factors, family relations, religion, social relations, behavior, and health. They were aged 14 to 17 years of age. They collected data during face-to-face interviews,
Age and SES were used as control variables in their multivariate analysis. For violent behaviors, the authors write:
Youths were asked how often they had engaged in the following behaviors; ‘had a fight in school’, ‘taken part in a rumble where a group of your friends were against another group’, injured someone badly enough to need bandages or a doctor’, ‘hit a teacher or supervisor at work (work supervisor)’, used a knife or gun or other object (like a club) to get something romantic a person’, ‘carried a knife or razor’, or ‘carried a gun’. All items used a Likert response, ranging from 1 (0 times) to 5 (4 or more times). Responses to each item were averages to calculate the behavior during the last year. Total score was calculated as the average of all items. Higher scores indicated more violent behaviors (a = 0.79). This measure has shown high reliability and validity and it has been used previously in several published reports.
This is a great questionnaire. The only thing I can think of that’s missing is fighting/arguing with parents.
In regards to testosterone assaying, they were assayed after 11 am to “control for changes due to diurnal rhythm” (Assari, Caldwell, and Zimmerman, 2014). I’m iffy on that since testosterone levels are highest at 8 am but whatever. This analysis is robust. Saliva was not taken if the subject had smoked or ingested something other than water or if a subject was pregnant. Assays should be taken as close to 8 am, as that’s when levels are highest. However one study does argue to extend the range to 8 am to 2 pm (Crawford et al, 2015) while other studies show that this only should be the case for older males (Long, Nguyen, and Stevermer, 2015). Even then assays were done at the higher end of the range as stated by Crawford et al (2015), so differences shouldn’t be too much.
86.4 percent of the sample was black whereas 13.4 percent were white. 41.2 percent of the subjects had some college education whereas 58.2 percent of the subjects lived with a partner or relative. 21.4 percent of the subjects were unemployed.
The mean age was 20.5 for both men and women, however, which will be a surprise to some, testosterone did not predict aggressive behavior in men but did in women. Testosterone and aggressive behavior were positively correlated, whereas there was a negative correlation between education and testosterone and aggressive behavior. Though education was associated with aggressive behavior in men but not women. So sex and education was associated with aggressive behavior (the sex link being women more privy to aggressive behavior while men are more privy to aggressive behavior due to lack of education). Females who had high levels of education had lower levels of aggressive behavior. Again: testosterone wasn’t associated with violent behavior in men, but it was in women. This is a very important point to note.
This was a community sample, so, of course, there were different results when compared to a laboratory setting, which is not surprising. Laboratory settings are obviously unnatural settings whereas the environment you live in every day obviously is more realistic.
This study does contradict others, in that it shows that there is no association between testosterone and aggression in men. However, still other research shows that testosterone is not linked to aggression or impulsivity, but to sensation-seeking, sexual experience or sociality (Daitzman and Zuckerman, 1980; Zuckerman, 1984). Clearly, testosterone is a beneficial hormone and due to the low correlation of testosterone with aggression (between .08 and .14; Book, Starzyk, and Quinsey, 2001; Archer, Graham-Kevan and Davies, 2005; Book and Quinsey, 2005). This paper, yet again, buttresses my arguments in regards to testosterone and aggressive behavior.
In regards to the contrast in the literature the authors describe, they write:
One of the many factors that may explain the inconsistency in these findings is the community versus clinical setting, which has been shown to be a determinant of these associations. Literature has previously shown that many of the findings that can be found in clinical samples may not be easily replicated in a community setting (36).
This is like the (in)famous, unreplicable stereotype threat (see Stroessner and Good). It can only be replicated in a lab, not in an actual educational setting. And it also seems that this is the case for testosterone and aggressive behavior.
Just because women have lower testosterone and are less likely to engage in aggressive behavior, that doesn’t mean that a relationship does not exist between females. “It is also plausible to attribute sex differences in the above studies to differential variations in the amount of testosterone among men and women” (Assari, Caldwell, and Zimmerman, 2014). This view supports the case that testosterone is linked to aggression in females, even though their range of testosterone is significantly lower than men’s, while it may also be easier to assay women for testosterone due to less diurnal variation in comparison to men (Book, Starzyk, and Quinsey, 2001).
Assari, Caldwell, and Zimmerman, (2014) also write (which, again, buttresses my arguments):
Age may explain some of the conflicting results across the studies. A meta-analysis of community and selected samples suggested that there might be only low to modest association between testosterone and aggression, with mean weighted correlations ranging from 0.08 to 0.14, in males. Overall, these meta-analyses suggest that the testosterone-aggression association is equally strong in 12 to 21-year-olds, as it is in 22 to 35-year-olds, but that it may be less strong in age groups younger than 12, than in those who are older.
So, testosterone may be associated with aggressive behavior and violence in women but not in men. In men, the significant moderator was education. It’s interesting to note that Mazur (2016) noted that young black males with little education had higher levels of testosterone than age-matched samples of other blacks. This, along with the evidence provided here, may be a clue that if the social environment changes, then so will higher levels of testosterone (as I have argued here).
They, perhaps taking too large of a leap here, argue that “aggressive behaviors may be more social and less biologically based among men” (Assari, Caldwell, and Zimmerman, 2014). Obviously social factors are easier to change than biological ones (in theory), so, they argue, preventative measures may be easier for men than women. More studies need to be done on the complex interactions between sex, testosterone, aggression, biology and the social environment which then shapes the aggressive behaviors of those who live there.
Testosterone and aggression studies are interesting. However, you must know a good amount of the literature to be able to ascertain good studies from the bad, what researchers should and should not have controlled for, time of assay, etc because these variables (some not in the author’s hands, however) can and do lead to false readings if certain variables are not controlled for. All in all, the literature is clearly points to, though other studies contest this at times, the fact that testosterone does not cause aggressive behavior in men. The myth needs to die; the data is piling up for this point of view and those who believe that testosterone causes aggressive behavior and crime (which I have shown it does not, at least for men) will soon be left in the dust as we get a better understanding of this pivotal hormone.
(In case anyone was going to use this as evidence that black women have higher levels of testosterone than white women, don’t do it because it’s not true. You’ll only embarrass yourself like this guy did. Read the comments and see him say that you don’t need scientific measurements, you only need to ‘observe it’ and through ‘observation’ we can deduce that black women have higher levels of testosterone than white women. This is not true. Quoting Mazur, 2016:
The pattern [high testosterone] is not seen among teenage boys or among females.
There is no indication of inordinately high T among young black women with low education.
Whoever still pushes that myth is an idealogue; I have retracted my article ‘Black Women and Testosterone‘, but idealogues just gloss over it and read what they think will bolster their views when I have provided the evidence to the contrary. It pisses me off that people selectively read things then cite my article because they think it will confirm their pre-conceived notions. Well too bad, things don’t work like that.)
There are a lot of conceptual problems with IQ tests that I never see talked about. The main ones are how the tests are constructed (to fit a normal curve, no less); to the fact that there is no construct validity to the tests (IQ tests aren’t calibrated against a biological model like breathalyzers are calibrated against a model of blood in the blood stream); and how the Raven’s Progressive Matrices test is actually biased despite being touted as the most culture-free test since all you’re doing is rotating abstract symbols to see what comes next in the sequence. These three assumptions have important implications for the ‘power’ of the IQ tests, the most important being the test construction and validity.
I) IQ test construction
IQ tests are constructed with the assumption that we know what IQ tests test (we don’t) and with the prior ‘knowledge’ of who is or is not intelligent. Test constructors construct the tests to reveal presumed differences between individuals.
It is assumed that 1) IQ scores lie on a normal distribution (they don’t) and 2) few natural bio functions conform to this curve. Another problem with IQ test construction is the assumption that it increases with age and levels off after puberty. Though this, like the other things, has been built into the test by choosing items that an increasing proportion of children pass. You can, of course, reverse this effect by choosing items that older people do well on and younger people don’t.
Further, they keep 50 percent of items that children get right while keeping a smaller proportion of items that children get right, which, in effect, presupposes who is or is not intelligent.
Though, you never see those who believe that IQ is a ‘good enough’ proxy for intelligence ever being this up. Why? This is very important for the validity of these tests. Because if how the tests are constructed is wrong and test scores are not to fit a normal distribution when no normal distribution actually exists for most human mental (including IQ scores) and physiological traits, then the assumptions and conclusions drawn from them are wrong. IQ tests are constructed with the prior idea of who is or is not ‘intelligent’ and this is done by how the items are chosen—50 percent of the items that people get right are kept while the smaller proportion of items people get right or wrong are kept. This is how this so-called ‘normal curve’ appears in IQ tests and is why the book The Bell Curve has the name it has. But bell curve don’t exist for a modicum of traits including IQ!!
II) IQ test validity
Another problem with IQ tests are its validity. People attempt to ‘prove’ its validity with correlating job performance success with IQ scores, though there are huge flaws in the studies purporting to show a .5 correlation between IQ and job performance (Richardson, 2002; Richardson and Norgate, 2015). IQ tests are not like, say, breathalyzers (which are calibrated against a model of blood alcohol) or white blood cell count (which is a proxy for disease in the body). Those two measures have a solid theoretical basis and underpinning; as blood alcohol rises, the individual had increased alcohol consumption. The same is true for white blood cell count. The same is not true for IQ tests.
One of the biggest measures used in regards to job performance and IQ testing (people attempt to use job performance to attempt to validate IQ tests) is supervisor rating. However, supervisory ratings are hugely subjective and a lot of factors that would have a supervisor be said to be a ‘good worker’ are not variables that entail just that job.
The only ‘validity’ that IQ test have is correlations with other IQ tests and tests like the SAT. This is not validity. Say the breathalyzer wasn’t calibrated against a model of blood alcohol in the body, would breathalyzers still be a valid tool to test people’s blood/alcohol level? On that same note let’s say that white blood cells wasn’t construct valid. Would we be able to reliably use white blood cell count as a valid measure for disease in the body? These very same problems plague IQ tests and people accept them as ‘proxies’ for intelligence, they test ‘enough of intelligence’ to be able to say that one is smarter than another because they scored higher in a test and therefore tap into this mystical ‘g’ that they have more of which is like a ‘power’ or ‘energy’.
These tests, therefore, are constructed with the idea of who is or is not intelligent and you can see that by looking at how the items are chosen for the test. That’s not scientific. So a true test of ‘intelligence’ may not even exist since these tests have this type of construct bias already in them.
IQ tests have no validity like breathalyzers and white blood cell count, and the so-called ‘culture-free’ IQ test Raven’s Progressive Matrices is anything but.
III) Raven’s and culture bias
I specifically asked Dr. James Thompson about Raven’s being culture-fair. I said that I recall Linda Gottfredson saying that people say that Ravens is culture-fair only because Jensen said it:
So that’s one thing about Ravens that crumbles. A quote from Ken Richardson’s book Genes, Brains, and Human Potential: The Science and Ideology of Intelligence:
It is well known that families and subcultures vary in their exposure to, and usage of, the tools of literacy, numeracy, and associated ways of thinking. Children will vary in these because of accidents of background. …that background experience with specific cultural tools like literacy and numeracy is reflected in changes in brain networks. This explains the importance of social class context to cognitive demands, but is says nothing about individual potential.
(This argument on social class is much more complex than ‘poor people are genetically predisposed to be dumb and poor’.
Consider a recent GCTA study by Plomin et al., who reported a SNP-based heritability estimate of 35% for “general cognitive ability” among UK 12 year olds (as compared to a twin heritability estimate of 46%) . According to the Wellcome Trust “genetic map of Britain,” striking patterns of genetic clustering (i.e. population stratification) exist within different geographic regions of the UK, including distinct genetic clusterings comprised of the residents of the South, South-East and Midlands of England; Cumbria, Northumberland and the Scottish borders; Lancashire and Yorkshire; Cornwall; Devon; South Wales; the Welsh borders; Anglesey in North Wales; Scotland and Ireland; and the Orkney Islands . Now consider the title of a study from the University and College Union: “Location, Location, Location – the widening education gap in Britain and how where you live determines your chances” . This state of affairs (not at all unique to the UK), combined with widespread geographic population stratification, is fertile ground for spurious heritability estimates.
I think this argument is interesting, and it throws a wrench into a lot of things, but more on that another day.)
In other words, items like those in the Raven contain hidden structure which makes them more, not less, culturally steeped than any other kind of intelligence testing items, like the Raven, as somehow not knowledge-based, when all are clearly learning dependent. Ironically, such cultural-dependency testing is sometimes tacitly admitted by test users. For example, when testing children in Kuwait on the Raven in 2006, Ahmed Abdel-Khalek and John Raven transposed the items “to read from left to right following the custom of Arabic writings.” (Richardson, 2017: 99)
Finally, we have this dissertation which shows that urban peoples score better than hunter-gatherers (relevant to this present article):
Reading was the greatest predictor of performance Raven’s, despite controlling for age and sex. Attendance was also strongly correlated with Raven’s performance. These findings suggest that reading, or pattern recognition, could be fundamentally affecting the way an individual problem solves or learns to learn, and is somehow tapping into ‘g’. Presumably the only way to learn to read is through schooling. It is, therefore, essential that children are exposed to formal education, have the motivation to go/stay in school, and are exposed to consistent, quality training in order to develop the skills associated with improved performance. (pg. 83)
This is telling: This means that there is no such thing as a ‘culture-free’ IQ test and there will always be something involved that makes it culture un-fair.
People may say ‘It’s only rotating pictures and shapes to get the final answer, how much schooling could you need??’, well as seen above with the Tsimane, schooling is very important to IQ tests since they test learned skills. I’ve seen some people claim that IQ tests don’t test learned ability and that it’s all native, unlearned ability. That’s a very incorrect statement.
So although the symbols in a test like the RPM are experience-free, the rules governing their changes across the matrix are certainly not, and they are more likely to be already represented in the minds of children from middle-class homes, less so in others. Performance on the Raven’s test, in other words, is a question not of inducing ‘rules’ from meaningless symbols, in a totally abstract fashion, but of recruiting ones that are already rooted in the activites of some cultures rather than others. Like so many problems in life, including fields as diverse as chess, science and mathematics (e.g. Chi & Glaser, 1985), each item on the Raven’s test is a recognition problem (matching the covariation structure in a stimulus array to ones in background knowledge) before it is a reasoning problem. The latter is rendered easy when the former has been achieved. Similar arguments can be made about other so-called ‘culture-free’ items like analogies and classifications (Richardson & Webster, 1996). (Richardson, 2002: pg 292-292)
Everyday life is also more complex than the hardest items on Raven’s Matrices, while the test is not complex in its demands compared to tasks undertaken in everyday life (Carpenter, Just, and Shell, 1990). They conclude that the cause is differences in working memory, but that is an ill-defined concept in psychology. They do say, though, that “The processes that distinguish among individuals are primarily the ability to induce abstract relations and the ability to dynamically manage a large set of problem-solving goals in working memory.” So item complexity doesn’t make Raven’s items more difficult for others, since everyday life is more complex.
I’ll end with a bit of physiology. What physiological process is does IQ mimic in the body? If it is a physiological process, surely you’re aware that physiological processes *are not* static. IQ is said to be stable at adulthood, what a strange physiological process. Let’s say for arguments’ sake that IQ really does test some intrinsic, biological process. Does it seem weird to you that a supposed real, stable, biological, bodily function of an individual would be different at different times?
There are a lot of assumptions about IQ tests that are never talked about. The most important being how the tests are constructed to fit a normal curve when most traits important for survival aren’t normally distributed. IQ tests are constructed with the assumption of who is or isn’t intelligent just on the knowledge of how the items are prepared for the test. When you look at how the tests are constructed you can see how they are constructed to fit the normal curve because most of their assumptions and conclusions rest on the reality of the normal curve. There is no construct validity to IQ tests, they’re not like breathalyzers for instance which are calibrated against a model of blood alcohol or white blood cell count as a proxy for disease in the body. Raven’s—despite what is commonly stated about the test—is not unbiased, it perhaps is the most biased IQ test of them all. This highlights the problems with IQ tests that are rarely ever spoken about, and should have you call into question the ‘power’ of the IQ test which assumes who is or isn’t intelligent ahead of time.
I was alerted to an article on the website (Ir)”RationalWiki” which in their own words “critique[s] and challenge[s] pseudoscience and the anti-science movement, explore[s] authoritarianism and fundamentalism, and analyze[s] how these subjects are handled in the media.” Unfortunately, it seems like the one who wrote this article (and is still adding to it) just selectively read certain articles and quote mined them.
The article on this website about me is an unfair mischaracterization of my views. Quotes will follow from the article with my comments.
In the opening paragraph they write:
NotPoliticallyCorrect is an Alt-right blog that promotes racialist pseudoscience and white nationalism; the owner posts as RaceRealist using the euphemism “racial realist” coined by the white supremacist J. P. Rushton who is extensively quoted on the blog.
- I’m not alt-right nor am I a white nationalist.
- I don’t promote ‘racialist pseudoscience’ nor do I promote ‘white nationalism’.
- Correct, Rushton did coin the term ‘race realist’, but he was not a ‘white supremacist’.
They continue, quoting an article of mine that I wrote almost two years ago titled Non-Western People are Abnormal to Our Society. I still stand by everything that I wrote in that article.
A racist crank obsessed with controversial topics such as race and IQ and eugenics, RaceRealist argues in a 2016 blog essay “Non-Western People are Abnormal to Our [Western] Societies” and its comments that “MENA” and “SSA’s” (i.e. people from the Middle-East, North Africa and Sub-Saharan Africa) as well as other non-Westerners are somehow abnormal to the US and Europe:
They then quote me:
MENA and SSA people are abnormal to Western societies. It’s clear that, on average, full-on acclimation is not possible.
One only needs to look at what is occurring in Western European countries to see that, on average, this is true.
In the same essay, RaceRealist goes on to post crude racism, such as “Negros” are biologically inferior:
Quoting me writing:
The same can be said for Negros[sic] in America as well. They are deviant, dysfunctional, they cause distress in our country and finally, they pose a danger to us, our families and societies as a whole. Just like those immigrants we have come into our countries who cannot assimilate because it’s not in their biology.
Except everything I wrote here was logically sound (last sentence notwithstanding). Look at the 4 d’s of abnormal psychology (which is the next quote they provide):
The “4 d’s of abnormality” and how they relate to our culture and the current culture/biology of those non-Western immigrants coming into our country is extremely telling. It’s clear that those people cannot assimilate into our societies because of differing biology and differing locations in which they evolved in. We chose our environments based on our biology. Environment increasingly depends on their genes, rather than being the cause of their exogenous behavior.
The 4 d’s of abnormality are deviance, dysfunction, distress and danger. Everything I wrote and then provided examples for in regards to the 4 d’s of abnormality are sound.
You can read my article Diversity in the Social Context for more evidence for this argument.
They then quote my article The Evolution of Jewish Nepotism writing:
RaceRealist is an anti-Semite who dislikes Ashkenazi Jews, accusing them of “derogating other ethnicities”; when discussing Ashkenazi Jews, he bizarrely maintains their higher average IQ is partly a product of “breeding with beautiful Roman women a few thousand years ago”, for which there exists no evidence.
I admit it is conjecture. Evidence exists for Jewish men migrating to Rome to mate with Roman women (Atzmon et al, 2010). I never stated that I ‘dislike Ashkenazi Jews’. In regards to the derogation, it’s true. Close-knit ethnic groups derogate the out-group (Sampasivam et al, 2016). Further, oxytocin promotes human ethnocentrism, which caused in-group favoritism and out-group derogation (Drew et al, 2010). In-groups derogate out-groups. Read the literature.
And the final thing the page shows is my tweet saying that “I finally made it on (Ir)”RationalWiki””:
to which they wrote:
Just because I have the numbers “88” in my handle doesn’t make me “alt-right” nor does it make me a “white nationalist.” I thought about changing it, then I realized that it’s good to weed out the people who aren’t serious about discussion and just look for things to discredit people that are meaningless to the conversation at hand. It tells you a lot about someone when they bring up irrelevant things. I’m not a white nationalist, nor am I an alt-righter. Just because I write about politics rarely and use them as an example (like in my article The Rise of Ethnocentrism and the Alt-Right: The Rebirth of Selfish Genes which I also disavow now that I realize that ‘selfish genes’ are a metaphor; Noble, 2011; Noble, 2013; Noble et al, 2014).
Take a look at the tags it tagged the article with: “Alt-righters, Pseudoscience, Racists, Internet kooks, Psuedoscience promoters, Alt-right, Internet Hate Sites.” Not an alrighter, I don’t push psuedoscience, I’m not a ‘racist’ (whatever that means). If you don’t like what I write, respond to any article you disagree with and explain why with logical, rational arguments. This piece is garbage and mischaracterizes my views using selective quotations (which, even then, failed to prove their point. No, numbers after a username are not evidence).
All in all, this article is garbage. It says that Rushton is ‘extensively quoted’, which is true for what I wrote in the beginning of this blog’s history, but not so for the past, say, 18 months. Rushton has been the target of my attacks on penis size, testosterone, and my personal favorite, r/K selection theory. But sure, go and dig in the archives for old articles to quote mine. This article written about me is dumb, doesn’t characterize my views correctly (calls me a ‘white nationalist’ and ‘alt-righter’). Selectively quote certain articles, assert that Rushton is ‘extensively quoted’ when I hardly discuss him anymore and when I do it’s about testosterone/to rebut him. (Ir)RationalWiki should think about reading a bit of my blog before characterizing me as something I’m not.
For the record, I don’t care about politics. I am not alt-right. I am not a white nationalist. I’m not an anti-semite. This will be updated to cover whatever else they decide to write about me. Hopefully it’s at least a bit closer to reality next time, because this article sucks.
Black-white differences in physiology can tell a lot about how the two groups have evolved over time. On traits like resting metabolic rate (RMR), basal metabolic rate (BMR), adiposity, heart rate, Vo2 max, etc. These differences in physiological variables between groups, then, explain part of the reason why there are different outcomes in terms of life quality/mortality between the two groups.
Right away, by looking at the average black and average white, you can see that there are differences in somatype. So if there are differences in somatype, then there must be differences in physiological variables, and so, this may be a part of the cause of, say, differing obesity rates between black and white women (Albu et al, 1997) and even PCOS (Wang and Alvero, 2013).
Resting metabolic rate
Resting metabolic rate is your body’s metabolism at rest, and is the largest component of the daily energy budget in modern human societies (Speakman and Selman, 2003). So if two groups, on average, differ in RMR, then one with the lower RMR may have a higher risk of obesity than the group with the higher RMR. And this is what we see.
Black women do, without a shadow of a doubt, have a lower BMR, lower PAEE (physical activity energy expenditure) and TDEE (total daily expenditure) (Gannon, DiPietro, and Poehlman, 2000). Knowing this, then it is not surprising to learn that black women are also the most obese demographic in the United States. This could partly explain why black women have such a hard time losing weight. Metabolic differences between ethnic groups in America—despite living in similar environments—show that a genetic component is responsible for this.
There are even predictors of obesity in post-menopausal black and white women (Nicklas et al, 1999). They controlled for age, body weight and body composition (variables that would influence the results—no one tell me that “They shouldn’t have controlled for those because it’s a racial confound!”) and found that despite having a similar waist-to-hip ratio (WHR) and subcutaneous fat area, black women had lower visceral fat than white women, while fasting glucose, insulin levels, and resting blood pressure did not differ between the groups. White women also had a higher Vo2 max, which remained when lean mass was controlled for. White women could also oxidize fat at a higher rate than black women (15.4 g/day, which is 17% higher than black women). When this is expressed as percent of total kcal burned in a resting state, white women burned more fat than black women (50% vs 43%). I will cover the cause for this later in the article (one physiologic variable is a large cause of these differences).
We even see this in black American men with more African ancestry—they’re less likely to be obese (Klimentidis et al 2016). This, too, goes back to metabolic rate. Black American men have lower levels of body fat than white men (Vickery et al, 1988; Wagner and Heyward, 2000). All in all, there are specific genetic variants and physiologic effects, which cause West African men to have lower central (abdominal) adiposity than European men and black women who live in the same environment as black men—implying that genetic and physiologic differences between the sexes are the cause for this disparity. Whatever the case may be, it’s interesting and more studies need to be taken out so we can see how whatever gene variants are *identified* as protecting against central adiposity work in concert with the system to produce the protective effect. Black American men have lower body fat, therefore they would have, in theory, a higher metabolic rate and be less likely to be obese—while black women have the reverse compared to white women—a lower metabolic rate.
Skeletal muscle fiber
Skeletal muscle fibers are the how and why of black domination in explosive sports. This is something I’ve covered in depth. Type II fibers contract faster than type I. This has important implications for certain diseases that black men are more susceptible to. Though the continuous contraction of the fibers during physical activity leads to a higher disease susceptibility in black men—but not white men (Tanner et al, 2001). If you’re aware of fiber type differences between the races (Ama et al, 1986; Entine, 2000; Caeser and Henry, 2015); though see Kerr (2010’s) article The Myth of Racial Superiority in Sports for another view. That will be covered here in the future.
Nevertheless, fiber typing explains racial differences in sports, with somatype being another important variable in explaining racial disparities in sports. Two main variables that work in concert are the somatype (pretty much body measurements, length) and the fiber type. This explains why blacks dominate baseball and football; this explains why ‘white men can’t jump and black men can’t swim’. Physiological variables—not only ‘motivation’ or whatever else people who deny these innate differences say—largely explain why there are huge disparities in these sports. Physiology is important to our understanding of how and why certain groups dominate certain sports.
This is further compounded by differing African ethnies excelling in different running sports depending on where their ancestors evolved. Kenyans have an abundance of type I fibers whereas West Africans have an abundance of type II fibers. (Genetically speaking, ‘Jamaicans’ don’t exist; genetic testing shows them to come from a few different West African countries.) Lower body symmetry—knees and ankles—show that they’re more symmetrical than age-matched controls (Trivers et al, 2014). This also goes to show that you can’t teach speed (Lombardo and Deander, 2014). Though, of course, training and the will to want to do your best matter as well—you just cannot excel in these competitions without first and foremost having the right physiologic and genetic make-up.
Further, although it’s only one gene variant, ACTN3 and ACE explain a substantial percentage of sprint time variance, which could be the difference between breaking a world record and making a final (Papadimitriou et al, 2016). So, clearly, certain genetic variants matter more than others—and the two best studied are ACTN3 and ACE. Some authors, though, may deny the contribution of ACTN3 to elite athletic performance—like one researcher who has written numerous papers on ACTN3, Daniel MacArthur. However, elite sprinters are more likely to carry the RR ACTN3 genotype compared to the XX ACTN3 genotype, and the RR ACTN3 genotype—when combined with type II fibers and morphology—lead to increased athletic performance (Broos et al, 2016). It’s also worth noting that 2 percent of Jamaicans carry the XX ACTN3 genotype (Scott et al, 2010), so this is another well-studied variable that lends to superior running performance in Jamaicans.
In regards to Kenyans, of course when you are talking about genetic reasons for performance, some people don’t like it. Some may say that certain countries dominate in X, and that for instance, North Africa is starting to churn out elite athletes, should we begin looking for genetic advantages that they possess (Hamilton, 2000)? Though people like Hamilton are a minority view in this field, I have read a few papers that there is no evidence that Kenyans possess a pulmonary system that infers a physiologic advantage over whites (Larsen and Sheel, 2015).
People like these three authors, however, are in the minority here and there is a robust amount of research that attests to East African running dominance being genetic/physiologic in nature—though you can’t discredit SES and other motivating variables (Tucker, Onywera, and Santos-Concejero, 2015). Of course, a complex interaction between SES, genes, and environment are the cause of the success of the Kalenjin people of Kenya, because they live and train in such high altitudes (Larsen, 2003), though the venerable Bengt Saltin states that the higher Vo2 max in Kenyan boys is due to higher physical activity during childhood (Saltin et al, 1995).
The last variable I will focus on (I will cover more in the future) is blood pressure. It’s well known that blacks have higher blood pressure than whites—with black women having a higher BP than all groups—which then leads to other health implications. Some reasons for the cause are high sodium intake in blacks (Jones and Hall, 2006); salt (Lackland, 2014; blacks had a similar sensitivity than whites, but had a higher blood pressure increase); while race and ethnicity was a single independent predictor of hypertension (Holmes et al, 2013). Put simply, when it comes to BP, ethnicity matters (Lane and Lip, 2001).
While genetic factors are important in showing how and why certain ethnies have higher BP than others, social factors are arguably more important (Williams, 1992). He cites stress, socioecologic stress, social support, coping patterns, health behavior, sodium, calcium, and potassium consumption, alcohol consumption, and obesity. SES factors, of course, lead to higher rates of obesity (Sobal and Stunkard, 1989; Franklin et al, 2015). So, of course, environmental/social factors have an effect on BP—no matter if the discrimination or whatnot is imagined by the one who is supposedly discriminated against, this still causes physiologic changes in the body which then lead to higher rates of BP in certain populations.
Poverty does affect a whole slew of variables, but what I’m worried about here is its effect on blood pressure. People who are in poverty can only afford certain foods, which would then cause certain physiologic variables to increase, exacerbating the problem (Gupta, de Wit, and McKeown, 2007). Whereas diets high in protein predicted lower BP in adults (Beundia et al, 2015). So this is good evidence that the diets of blacks in America do increase BP, since they eat high amounts of salt, low protein and high carb diets.
Still, others argue that differences in BP between blacks and whites may not be explained by ancestry, but by differences in education, rather than genetic factors (Non, Gravlee, and Mulligan, 2012). Their study suggests that educating black Americans on the dangers and preventative measures of high BP will reduce BP disparities between the races. This is in-line with Williams (1992) in that the social environment is the cause for the higher rates of BP. One hypothesis explored to explain why this effect with education was greater in blacks than whites was that BP-related factors, such as stress, poverty and racial discrimination (remember, even if no racial discrimination occurs, any so-called discrimination is in the eye of the beholder so that will contribute to a rise in physiologic variables) and maybe social isolation may be causes for this phenomenon. Future studies also must show how higher education causes lower BP, or if it only serves as other markers for the social environment. Nevertheless, this is an important study in our understanding of how and why the races differ in BP and it will go far to increase our understanding of this malady.
This is not an exhaustive list—I could continue writing about other variables—but these three are some of the most important as they are a cause for higher mortality rates in America. Understanding the hows and whys of these variables will have us better equipped to help those who suffer from diseases brought on by these differences in physiological factors.
The cause for some of these physiologic differences come down to evolution, but still others may come down to the immediate obesogenic environment (Lake and Townshend, 2006) which is compounded by lower SES. Since high carbs diets increase BP, this explains part of the reason why blacks have higher BP, along with social and genetic factors. Muscle fiber typing is set by the second trimester, and no change is seen after age 6 (Bell, 1980). Resting metabolic rate gap differences between black and white women can be closed, but not completely, if black women were to engage in exercise that use their higher amounts of type II muscle fibers (Tanner et al, 2001). This research is important to understand differences in racial mortality; because when we understand them then we can begin to theorize on how and why we see these disparities.
Physiologic differences between the races are interesting, they’re easily measurable and they explain both disparities in sports and mortality by different diseases. Once we study these variables more, we will be better able to help people with these variables—race be dammed. Race is a predictor here, only because race is correlated with other variables that lead to negative health outcomes. So once we understand how and why these differences occur, then we can help others with similar problems—no matter their race.
Do you need to look at genetic differences between races to see if race is real? Some may argue that you do, and when you do you’ll see that genetic variation is too small to say that race exists. However, other arguments exist that do not look at genetic differences between races, but look at geographic ancestry, reproductive isolation between races, and morphologic differences. Those three variables are enough to prove the existence of race without looking at genetic differences between races. They do correspond to genetic differences between races. The four concepts I will briefly lay out are from Michael Hardimon, professor of philosophy at University of California, San Diego. The concepts are the racialist concept of race, minimalist concept of race concept, populationist concept of race, and the socialrace concept of race. One doesn’t need to look at the racialist concept of race to prove the existence of race, which I will prove below.
Michael Hardimon published Rethinking Race: The Case for Deflationary Realism earlier this year. In the book, he makes the case that race exists if minimalist race exists (I will get into what minimalist race entails below). Nevertheless, race deniers will say that even by looking at variables such as morphology, reproductive isolation, and geographic ancestry, race as a concept is scientifically invalid. This is patently false.
Concepts of race
The racialist concept of race
Hardimon’s first race concept is the racialist concept. The racialist concept (keep in mind, this is, as Hardimon writes on page 17 of his book Rethinking Race “the specific concept I have dubbed “the racialist concept” which “is hierarchal“) as defined by Hardimon holds that “racialist race is the idea of a fundamental division between groups and individuals” (Hardimon, 2017: 17). I think that Hardimon strawmans the racialist concept as he as defined it, but that’s for another day.
He also says that the racialist concept “is closely associated with racism” while the terms racialism and racism are “sometimes used interchangeably” (Hardimon, 2017: 17).
His argument against the racialist concept of race (as he defines it) is as follows (Hardimon, 2017: 21):
A third line of argument starts from the idea that in order for racialist races to exist, certain things must be true of human genetics, namely the following:
(a) The fraction of human genetic diversity between populations must exceed the fraction of diversity between them.
(b) The fraction of human genetic diversity within populations must be small.
(c) The fraction of diversity between populations must be large.
(d) Most genes must be highly differentiated by race.
(e) The variation in genes that underlie obvious physical differences must be typical of the genome in general.
(f) There must be several important genetic differences between races apart from the genetic differences that underlie obvious physical differences.
Note: (b) says that racialist races are genetically racially homogeneous groups; (c)-(f) say that racialist races are distinguised by major biological differences.
Call (a)-(f) the racialist concept of race’s genetic profile.
Now that his argument against the racialist concept (as he defines it) is laid out, you can see why I said that I think he strawmans the racialist concept. But I’ll get into that another day.
He then cites Lewontin’s (1972) analysis of blood groups by race as evidence against the racialist concept. Lewontin found that 85.4 percent of total human variation fell within populations. He also found that populations that populations classically defined as human races (Caucasians, Africans, Mongoloids, South Asian Aborigines, American Indians, and Oceanians) accounted for 8.3 percent of total human variation. Total variation between the classically defined races accounted for 6.3 percent of the variance.
It’s worth noting that the numbers given by Lewontin are true; where he goes wrong is assuming that there is no taxonomic significance for race based on the data he got from his analysis. “Call this Lewontin’s cleaver,” writes Hardimon on page 22.
Then in 2002, 31 years after Lewontin published his analysis, A.W.F. Edwards published his paper Human Genetic Diversity: Lewontin’s Fallacy. (Edwards, 2003). In the paper, Edwards argues that Lewontin’s conclusion is incorrect. Edwards (2003: 800-801) writes in his conclusion (emphasis mine):
There is nothing wrong with Lewontin’s statistical analysis of variation, only with the belief that it is relevant to classification. It is not true that ‘‘racial classification is … of virtually no genetic or taxonomic significance’’. It is not true, as Nature claimed, that ‘‘two random individuals from any one group are almost as different as any two random individuals from the entire world’’, and it is not true, as the New Scientist claimed, that ‘‘two individuals are different because they are individuals, not because they belong to different races’’ and that ‘‘you can’t predict someone’s race by their genes’’. Such statements might only be true if all the characters studied were independent, which they are not.
Of course, Lewontin’s conclusion is fallacious because small genetic differences do not entail that racial classification that race has no taxonomic significance (Richard Dawkins accepts the taxonomic existence of race). As you can see from the quote from Edwards, he does not object to Lewontin’s analysis of the races, he objects to his conclusion—namely that races do not exist based on the within-race variation being greater than between-race variation.
On page 22-23, Hardimon writes about Edwards’ objection to Lewontin’s conclusion:
Lewontin’s locus-by-locus analysis (which does not consider the possibility of a correlation between individual loci) does not preclude the possibility that individual loci might be correlated in such a way that people could be grouped into traditional racial categories. The underlying thought is that racial classification would have “taxonomic significance” were it possible to group people into traditional racial categories by making use of correlations between individual loci. However, Lewontin’s argument that there are no racialist races because the component of within-race genetic variation is larger than the component of between-race variation is untouched by Edwards’s objection.
In 2002, Rosenberg et al, in their paper Genetic Structure of Human Populations confirmed Lewontin’s analysis. They looked at 377 autosomal loci in 1,056 individuals from 52 populations and found that within-population differences between major groups (Africa, Europe, Asia, the Middle East, Central and South Asia, East Asia, Oceania, and America) accounted for 3-5 percent of genetic variation while genetic differences between individuals accounted for 93-95 percent of genetic variation. So Rosenberg et al (2002) confirmed Lewontin’s (1972) analysis—though do recall that Lewontin’s conclusion is incorrect. According to Hardimon’s interpretation of the racialist concept of race, both Lewontin’s and Rosenberg et al’s analysis disprove the racialist concept of race, but that doesn’t mean that there is no scientific basis for the biological reality of race (Hardimon, 2012).
The minimalist concept of race
The minimalist concept of race is similar to the racialist concept, though there are some stark differences. It does not say that there are intrinsic differences between races—call them essences if you will), but it does say that you can distinguish races by patterns of different physical features such as skin color, hair type, nose shape, morphology, etc, which then correspond to differences in geographic ancestry in geographically, genetically isolated breeding populations.
The minimalist concept of race further states that (i) races are distinguised from other races by patterns of visible physical features; (ii) the members are linked by a common ancestry which is peculiar to members of the group; and (iii) this group must originate from a distinct location.
The minimalist concept of race does not require: that the fraction of human genetic diversity between minimalist races is larger than the fraction of diversity within them; it is compatible with within-race diversity being large and between-race diversity being small; it does not require most genes to be highly differentiated by race; it does not require the existence of a lot genetic differences between races that underlie more than the phenotypic differences already noticed; the concept does not imply that there can be predictions made from yet unstudied characteristics; it finally does not require any genetic differences between races other than those found in the genes that underlie differences in physical appearance between race. This is called the minimalist concept of biological race (Hardimon, 2017: 66) and it survives all objections from Lewontin’s and Rosenberg et al’s analysis of between-race genetic variation.
This is my favorite race concept, personally, because it covers any and all objections from the race-denialist crowd—people who deny any genetic differences between races—because the only genetic differences it counts on are those physical traits that are already noticed.
Hardimon (2017: 29) writes:
Such readers should feel free to regard the minimalist concept of race, that is, as a concept that, though in many respects similar to the ordinary concept, is nonetheless distinct from it. What I would insist on is that minimalist races (groups satisfying the minimalist concept of race) are *races* (that is races so properly called)—either because the minimalist concept of race just is the ordinary concept of race or because it captures enough of the ordinary concept of race for minimalist races to be counted as races. My view is that if it can be shown that minimalist races exist, races exist. And if it can be shown that *minimalist race* is real, race is real.
The populatonist concept of race
The populationist concept of race is a nonessentialist, non-hierarchical concept of race that slightly differs from the minimalist concept of race. The populationist concept of race can be said to be a scientific concept of race (as can the minimalist concept) because it characterizes races as groups belonging to different groups of biological descent, they are distinguished by patterns of phenotypic differences, and these phenotypic differences trace back to geographically separated and genetically isolated founding populations.
The populationist concept of race also holds that “A race is a subdivision of Homo sapiens—a group or population that exhibits a distinctive pattern of genetically transmitted phenotypic characters that corresponds to the group’s geographical ancestry and belongs to a biological line of descent initiated by a geographically separated and reproductively isolated founding population” (Hardimon, 2017: 99). So with these criteria, you can see that even if you do not accept the racialist concept of race (as Hardimon defines it), you can still be a race realist. The populationist concept is likely to exist, and if the populationist concept of race exists then race is real.
Defining race as geographically and reproductively isolated breeding populations that share a common line of biological descent with similar phenotypic characters is as barebones a concept of race as you can get—and it is perfectly in line with how most people view races on the basis of phenotypic characterization. The populationist concept of race supposes that numerous concepts from the racialist concept of race are true—but do not presuppose any to-be-studied differences between those races. The strength of the populationist argument, as you can see, is very strong and it holds up to numerous lines of criticism very well. Although both the populationist and minimalist race concepts do not presupposed any to-be-studied differences between races, this still is not good enough for race deniers.
It is clear that without even looking at the brain and physiological differences between races, that race does indeed exist and it does—contrary to popular belief—have implications for people’s health of certain races.
The socialrace concept of race
Finally, the last concept of race laid out by Hardimon is the concept of socialrace. The concept of socialrace takes a race to be a racialist race, it refers to a position that is occupied by a social group that is a socialrace, and the socialrace concept refers to the system of social positions that are socialraces. This concept of race is, clearly, different from the minimalist and populationist race concepts but does indeed correlate with popular notions of race (and would correlate with the minimalist and populationist concept of race very well). The socialrace concept is, basically, what is believed to be racialist races.
The concept of socialrace is a concept of race as a social group (Hardimon, The Ontology of Race: 31)
The socialrace concept differs from the minimalist and populationist concept of race in that it looks at so-called social—not biological—correlates of race. Though, still, the socialrace concept can be said to show the reality of race since how one socially defines themselves correlates almost perfectly with geographic ancestry (which is a prerequisite for the existence of the minimalist concept of race and the populationist concept of race) (Tang et al, 2005). They showed that self-identified racial categories lined up almost perfectly with geographic ancestry (99.86 percent of the time). So, as you can see, the concept of socialrace also gives credence to the existence of the minimalist and populationist concepts of race.
This concept of race—as its name implies—does not talk race is a biological manner, but a social one, as its name implies. However, due to the extremely high chance that one’s self-identified race (their socialrace) lines up with the geographic ancestry of the classical races, we can see that the socialrace concept further buttresses the argument for the existence for the reality of the minimalist concept of race and the populationist concept of race.
The socialrace concept is kind of like Templeton (2014) defines race: that human races exist in a cultural sense, but not biologic sense. I have shown, though, that races exist in a cultural, social, and biological sense with the arguments presented in this article. Socialrace, culturalrace, whatever you want to call it, it is evidence for the existence of race.
Race exists whether or not the racialist position of race (as Hardimon defines it) is true or not. The minimalist concept of race and populationist concept of race show that race is real while the concept of socialrace further lends credence to the biological models of the minimalist and populationist concept of race. Even still, people who deny race because the genetic distance between races is too small for their to be any meaningful differences between them do not accept that three arguments above (sans the racialist concept) for the existence of race. They’ll still talk about the genetic differences between them and, say, morphology, but the minimalist concept of race and the populationist concept of race define race in enough of a way that genetic differences do not need to be looked at—we can only look at reproductive isolation, morphology, geographic ancestry and physical differences between minimalist and populationist races such as hair, nose, and skin color along with morphological differences.
Minimalist and populationist races exist and are a biological reality. We can take those two concepts to be a scientific basis for race. While we can take the concept of socialrace not as a biological concept, but as a social concept and we can then say that socialrace is socially real while being a significant social reality. That social reality is manifested by noticing different racial phenotypes, along with differences in SES, educational attainment, etc, and placing different races in different average social positions, which would correlate with the concepts of race mentioned above. This also correlated nearly perfectly with geographic ancestry. So, I’m saying it again, the existence of race as a social reality is real; the existence of socialrace buttresses the arguments for both the existence of the minimalist concept of race and the populationist concept of race—both of which are scientific concepts of race.
Minimalist races exist, and is a superficial biological reality, populations races may exist and if they exist, they are a relatively superficial biological reality. Socialraces exist and are a social reality which also lend credence to the minimalist and populationist concepts. I personally am privy to the minimalist race concept because it is shown to be real, so race is real.
In sum, race exists whether you look at genetic differences between races or not, morphology, geographic ancestry, reproductive and genetic isolation are all you need to prove the existence of race. There is a scientific concept of race, and the minimalist and populationist race concepts provide the existence for it, while the socialrace concept does as well. It is clear that for a scientific concept of race, you only need phenotypic variation, morphologic variation between races,
(Also read the American Rennaisance review for the book, A Tactical Retreat for Race Denial. I think it is balanced and fairly written, though a bit biased and doesn’t account for Hardimon’s views well enough in my opinion.)
Here is my reply to Jared Taylor’s new article over at AmRen Breakthroughs in Intelligence:
“The human mind is not a blank slate; intelligence is biological”
The mind is not a ‘blank slate’, though there is no ‘biological’ basis for intelligence (at least in the way that hereditarians believe). They’re just correlations. (Whatever ‘intelligence’ is.)
“there is no known environmental intervention—including breast feeding”
There is a causal effect of breast feeding on IQ:
While reported associations of breastfeeding with child BP and BMI are likely to reflect residual confounding, breastfeeding may have causal effects on IQ. Comparing associations between populations with differing confounding structures can be used to improve causal inference in observational studies.
Brion, M. A., Lawlor, D. A., Matijasevich, A., Horta, B., Anselmi, L., Araújo, C. L., . . . Smith, G. D. (2011). What are the causal effects of breastfeeding on IQ, obesity and blood pressure? Evidence from comparing high-income with middle-income cohorts. International Journal of Epidemiology, 40(3), 670-680. doi:10.1093/ije/dyr020
Breastfeeding is related to improved performance in intelligence tests. A positive effect of breastfeeding on cognition was also observed in a randomised trial. This suggests that the association is causal.
Horta, B. L., Mola, C. L., & Victora, C. G. (2015). Breastfeeding and intelligence: a systematic review and meta-analysis. Acta Paediatrica, 104, 14-19. doi:10.1111/apa.13139
“before long we should be able to change genes and the brain itself in order to raise intelligence.“
Which genes? 84 percent of genes are expressed in the brain. Good luck ‘finding’ them…
These results corroborate with the results from previous studies, which have shown 84% of genes to be expressed in the adult human brain …
Negi, S. K., & Guda, C. (2017). Global gene expression profiling of healthy human brain and its application in studying neurological disorders. Scientific Reports, 7(1). doi:10.1038/s41598-017-00952-9
“Normal people can have extraordinary abilities. Prof. Haier writes about a non-savant who used memory techniques to memorize 67,890 digits of π! He also notes that chess grandmasters have an average IQ of 100; they seem to have a highly specialized ability that is different from normal intelligence. Prof. Haier asks whether we will eventually understand the brain well enough to endow anyone with special abilities of that kind.”
Evidence that intelligence is not related to expertise.
“It is only after a weight of evidence has been established that we should have any degree of confidence in a finding, and Prof. Haier issues another warning: “If the weight of evidence changes for any of the topics covered, I will change my mind, and so should you.” It is refreshing when scientists do science rather than sociology.”
Even with the “weight of evidence”, most people will not change their views on this matter.
“Once it became possible to take static and then real-time pictures of what is going on in the brain, a number of findings emerged. One is that intelligence appears to be related to both brain efficiency and structure”
Patterns of activation in response to various fluid reasoning tasks are diverse, and brain regions activated in response to ostensibly similar types of reasoning (inductive, deductive) appear to be closely associated with task content and context. The evidence is not consistent with the view that there is a unitary reasoning neural substrate. (p. 145)
Nisbett R. E., Aronson J., Blair C., Dickens W., Flynn J., Halpern D. F., Turkheimer E. Intelligence: New findings and theoretical developments. American Psychologist. 2012;67:130–159. doi: 10.1037/a0026699.
“Early findings suggested that smart people’s brains require less glucose—the main fuel for brain activity—than those of dullards.”
Cause and correlation aren’t untangled; they could be answering questions in a familiar format, for instance, and this could be why their brains show less glucose consumption.
“It now appears that grey matter is where “thinking” takes place, and white matter provides connections between different areas of grey matter. Some brains seem to be organized with shorter white-matter connections, which appear to allow more efficient communication, and there seem to be sex differences in the ways the part of the brain are connected. One of the effects of aging is deterioration of the white-matter connections, which reduces intelligence.”
Read this commentary (pg. 162): Norgate, S., & Richardson, K. (2007). On images from correlations. Behavioral and Brain Sciences, 30(02), 162. doi:10.1017/s0140525x07001379
“Brain damage never makes people smarter”
This is wrong:
You would think that cutting out one-half of people’s brains would kill them, or at least leave them vegetables needing care for the rest of their lives. But it does not. Consider this striking story. A boy starts having seizures at 10 years of age when his right cerebral hemisphere atrophies. By the time he is 12, the left side of his body is paralyzed. When he is 19, surgeons decide to operate and remove the right side of his brain, as it is causing gits in his intact left one. You might think this would lower his IQ or leave him severely retarded, but no. His IQ shoots up 14 points, to 142! The mystery is not so great when you realize that the operation has gotten rid of the source of his fits, which had previously hampered his intelligence. When doctors saw him 15 years later, they described him as “having obtained a university diploma . . . [and now holding] a responsible administrative position with a local authority.”
Skoyles, J. R., & Sagan, D. (2002). Up from dragons: the evolution of human intelligence. New York: McGraw-Hill (pg. 282)
“Prof. Haier wants a concerted effort: “What if a country ignored space exploration and announced its major scientific goal was to achieve the capability to increase every citizen’s g-factor [general intelligence] by a standard deviation?””
Don’t make me laugh. You need to prove that ‘g’ exists first. Glad to see some commentary on epigenetics that isn’t bashing it (it is a real phenomenon, though the scope of it in regards to health, disease and evolution remains to be discovered).
As most readers may know, I’m skeptical here and a huge contrarian. I do not believe that g is physiological and if it were then they better start defining it/talking about it differently because I’ve shown that if it were physiological then it would not mimick any known physiological process in the body. I eagerly await some good neuroscience studies on IQ that are robust, with large ns, their conclusions show the arrow of causality, and they’re not just making large sweeping claims that they found X “just because they want to” and are emotionally invested in their work. That’s my opinion about a lot of intelligence research; like everyone, they are invested in their own theories and will do whatever it takes to save face no matter the results. The recent Amy Cuddy fiasco is the perfect example of someone not giving up when it’s clear they’re incorrect.
I wish that Mr. Taylor would actually read some of the literature out there on TBI and IQ along with how people with chunks of their brains missing can have IQs in the normal range, showing evidence that most a lot of our brain mass is redundant. How can someone survive with a brain that weighs 1.5 pounds (680 gms) and not need care for the rest of his life? That, in my opinion, shows how incredible of an organ the human brain is and how plastic it is—especially in young age. People with IQs in the normal range need to be studied by neuroscientists because anomalies need explaining.
If large brains are needed for high IQs, then how do these people function in day-to-day life? Shouldn’t they be ‘as dumb as an erectus’, since they have erectus-sized brains living in the modern world? Well, the human body and brain are two amazing aspects of evolution, so even sudden brain damage and brain removal (up to half the brain) does not show deleterious effects in a lot of people. This is a clue, a clue that most of our brain mass after erectus is useless for our ‘intelligence’ and that our brains must have expanded for another reason—family structure, sociality, expertise, etc. I will cover this at length in the future.
Last week a study was published stating that white men who exercised 3 times the recommendation of 1.5 hours (450 minutes, 7.5 hours) had a higher chance of getting coronary artery calcification (CAC), which is the accumulation of plaque and calcium in the arteries of the heart. You, of course see news headlines such as: “Physically active white men at high risk for plaque buildup in arteries“; “White Men Who Exercise Every Day Have 86 Per Cent Higher Risk of Heart Disease Than Black Men, Study Claims“; “Excessive Exercise May Harm The Heart, Study Suggests “; “Excessive exercise increases risk of arterial plaque buildup in white men“; (and my personal favorite headline about this study): “You can exercise yourself to death, says new study“. People just passing by and reading the title (like most do) may then conclude that “they’re saying not to exercise because of CAC.” No, this is not what they are saying at all.
The Coronary Artery Risk Development in Young Adults (CARDIA) study is one of the most important studies in the study of coronary heart disease that have been undertaken. It is a sample of men and women, about equal numbers of each race, from Birmingham, Alabama; Chicago, Illinois; Minneapolis, Minnesota; and Oakland, California. The study began in 1985-86 and there were follow-up examinations at “1987-1988 (Year 2), 1990-1991 (Year 5), 1992-1993 (Year 7), 1995-1996 (Year 10), 2000-2001 (Year 15), 2005-2006 (Year 20), 2010-2011 (Year 25), and 2015-2016 (Year 30).” The CARDIA website writes:
Data have also been collected on physical measurements such as weight and body composition as well as lifestyle factors such as dietary and exercise patterns, substance use (tobacco and alcohol), behavioral and psychological variables, medical and family history, and other chemistries (e.g., insulin).
So there is a goldmine of information to be gleaned from this data. The study that is getting press in the news uses data from this cohort.
The study is titled 25-Year Physical Activity Trajectories and Development of Subclinical Coronary Artery Disease as Measured by Coronary Artery Calcium by Laddu et al (2017). They studied three cohorts by the amount of time they exercised per week: below requirement, at requirements, or above requirements. It is recommended to exercise at least 150 minutes per week.
There were 3,175 men and women who participated in the CARDIA study between 1985 and 2011 who had CAC data available for 25 years. About 47.4 percent of the sample was black, with 56.6 being women. The cohort “consisted of 18.9% black men, 24.6% white men, 28.6% black women, and 28.0% white women” (Laddu et al, 2017).
Of the three activity levels they studies (below 150 minutes, 150 minutes, and over 150 minutes), they observed that white men who exercised 3 times the weekly recommendation (150 minutes(3)= 450 minutes=7.5 hours) had a higher chance of developing CAC. It’s worth noting that exercise time was self-reported (which is the only way I can see how something like this would work, are you supposed to follow people with a camera every day to see how long they engage in physical activity?).
In regards to the physical activity measurement, Laddu et al (2017) write:
At each of the 8 examinations, self-reported leisure-time PA was ascertained by the interviewer-administered CARDIA Physical Activity History Questionnaire.17 Participants were asked about the frequency of participation in 13 specific categories (8 vigorous intensity and 5 moderate intensity) of recreational sports, exercise, home maintenance, and occupational activities during the previous 12 months. Intensity for each activity was expressed as metabolic equivalents (METs), in which 1 MET is defined as the energy expended at rest, which is approximately equivalent to an oxygen consumption of 3.5 mL per 1 kg of body weight per minute.18Vigorous activities (≥6 METs) included running or jogging; racquet sports; biking; swimming; exercise or dance class; job lifting, carrying, or digging; shoveling or lifting during leisure; and strenuous sports. Moderate-intensity activities (3-5 METs) included nonstrenuous sports, walking and hiking, golfing and bowling, home exercises or calisthenics, and home maintenance or gardening.19 Each activity was scored according to whether it was performed for 1 hour or longer during any 1 month during the past year, the number of months it was performed at that level, and the number of months the activity was performed frequently. Each activity was then assigned an intensity score, ranging from 3 to 8 METs, and a duration threshold (ranging from 2-5 hours per week), above which participation was considered to be frequent.20
This is a good metric; though I would like to see a study that looks at just gym-going activity and death, time spent in the gym strength training/moderate to intense cardio. Nevertheless, white men who reported more physical activity had a higher chance of acquiring CAC. Though I can see people’s recall being hazy, people over/under reporting, etc etc.
White men who exercised 7.5 hours per week were 27 percent more likely to get CAC, whereas blacks who exercised that much were at no greater risk to acquire CAC when compared to whites (7.5 hours of exercise compared to less than 2.5 hours per week). Black women who exercised less than the recommendations had a higher chance of acquiring CAC. The researchers couldn’t ascertain why white men who exercised three times the recommendations had such a higher chance of acquiring CAC by the time they reached middle age, but Dr. Jamal Rana says “however this plaque buildup may well be of the more stable kind, and thus less likely to rupture and causes heart attack, which was not evaluated in this study.” The head author, Dr. Deepika Laddu also reiterated: “it does not suggest that anyone should stop exercising.” So people who just read these click bait headlines who say “They’re telling whites not to exercise!”, you’re wrong and you should read papers and not news articles.
This is the perfect example of people reading click baity, fear-mongering headlines and running with it. I saw some people saying “They’re telling us not to exercise!” No. If you were to read the paper and any serious news articles on the matter, you’d see that they do not recommend that people do not exercise. Now the question is, why do whites who exercise more than 7.5 hours per week have a higher chance of acquiring heart disease? I can think of a few explanations (though they are not satisfactory): 1) genes: which genes? Why? How do they interact with the body over time to lead to arterial calcification?; 2) dietary habits: I’d like to know what their diet was like and see their macro composition, carbohydrates, not saturated fat, causes heart disease (Siri-Tirino et al, 2010; de Souza et al, 2015) so that may be a huge contributing factor.
Nevertheless, this is yet another physiological race difference. Oddly enough, black men are more likely than white men to have hypertension (Hicken et al, 2013).
Even though black men, on average, have higher rates of hypertension than white men, white men who are physically active for 7.5 had a higher chance of acquiring CAC than those who exercised less than 2.5 hours per week. This effect wasn’t seen in black men who had physical activity at that level, which, of course, implies that differences in genes and SES underlie this difference. I await more papers into this matter into the mechanisms of how and why this occurs and will ruminate on this myself in the future. No, this study does not tell white men not to exercise.
Evidence for Natural Selection in Humans: East Asians Have Higher Frequency of CASC5 Brain Size Regulating Gene
Brain size is one physical difference that the races differ on. East Asians have bigger brains than Europeans who have bigger brains than Africans (Beals et al, 1984; Rushton, 1997). What caused these average differences and the ultimate causes for them have been subject to huge debate. Is it drift? Natural/sexual selection? Mutation? Gene flow? Epigenetic? One reason why brains would need to be large in colder climates is due to heat retention, while in tropical climates heads need to be smaller to dissipate heat. One of the biggest criticisms of HBD is that there is no/little evidence of recent natural selection between human races. Well, that has changed.
CASC5 “performs two crucial functions during mitosis, being required for correct attachment of chromosome centromeres to the microtubule apparatus, and also essential for spindle-assembly checkpoint (SAC) signaling” (Shi et al, 2016). The gene has been found to be important in recent human evolution along with neurogenesis.
Shi et al (2016) genotyped 278 Han Chinese (174 females and 104 males with a mean age of 36) who were free of maladies or genetic defects. They had the coding sequences of CASC5 for humans, chimpanzees, gorillas, baboons, gibbons, orangutans, tarsiers, Denisovans, and Neanderthals. They downloaded genotypes from the Human Genome Project for their analysis.
They compared CASC5 among three human species: humans, Neanderthals, and Denisovans. Using chimpanzees as an outgroup, they discovered 45 human-specific mutations, 48 Neanderthal-specific mutations, and 41 Neanderthal-specific mutations. Further, when one exon region was aligned among modern humans, non-human primates and other mammalian species, 12 amino acid sites showed divergence between modern humans, Neanderthals, and Denisovans with 8 occurring in modern humans. Of the 8 sites in humans, 6 are preserved which implies that they were important in our evolutionary history.
Shi et al (2016) write:
At the population level, among the 8 modern human amino acid changes, two (H159R and G1086S) are fixed in current human populations, and the other six are polymorphic Fig. 1). Surprisingly, 5 of the 6 amino acid polymorphic sites showed deep between-population divergence in allele frequencies. East Asians possess much higher frequencies of the derived alleles at four sites (T43R-rs7177192, A113T-rs12911738, S486A-rs2412541 and G936R-rs8040502) as compared to either Europeans or Africans (Fig. 1), while E1285K-rs17747633 is relatively enriched in Europeans (46%), and rare in East Asians (10%) and Africans (3%). No between-population divergence was observed for T598 M-rs11858113 (Fig. 1).
So East Asians have a much higher frequency of this derived trait. This is direct evidence for natural selection in recent human evolution in regards to the physical structure of the brain.
Since most of the amino acid polymorphic sites showed between-population divergence, they decided to analyze the three classical races using 1000 genomes. The variation between the races could be due to either genetic drift or natural selection. When they analyzed certain gene regions, they observed a signal of positive selection for East Asians but not Europeans or Africans. They further tested this selection signal using “the standardized integrated haplotype score (iHS) which is used for detecting recent positive selection with incomplete sweep (i.e. the selected allele is not yet fixed)” (Shi et al, 2016). Using this method, they discovered a few SNPs with large iHS values in Europeans (7 SNPs at 4.2 percent) and none in Africans.
They also conducted a genome-wide scan of Fst, iHS, and “XPCLR (searching for highly differentiated genomimc regions as targets of selective sweeps)” (Shi et al, 2016). Several SNPs had high Fst, iHS and XPCLR scores, which indicate that these alleles have been under positive selection in East Asians. Among the fixed amino acid sites in human populations, East Asians showed 5, Europeans showed 1, and Africans showed 0 which, the authors write, “[imply] that these amino acid changes may have functional effects” (Shi et al, 2016). Furthermore, using the HDGP, they obtained the frequency of the 6 amino acid sites in 53 populations. This analysis showed that 4 of the 6 amino acid sites are “regionally enriched in East Asia .. in line with the suggested signal of population-specific selection in this area” (Shi et al, 2016).
Then, since CASC5 is a brain size regulating gene, they looked for phenotypic effects. They recruited 167 Han Chinese (89 men, 178 women) who were free of maladies. They genotyped 11 SNPs and all of the frequencies followed Harvey-Weinberg Equilibrium (which states that allele and genotype frequencies will remain constant in a population from generation to generation in the absence of evolutionary pressures; Andrews, 2010). In the female sample, 5 regions were related to gray matter volume and four were on the amino acid polymorphic sites. Interestingly, the four alleles which showed such a stark difference between East Asians and Europeans and Africans showed more significant associations in Han Chinese females than males. Those carrying the derived alleles had larger brain volumes in comparison with those who had the ancestral alleles, implying recent natural selection in East Asia for brain size.
Shi et al (2015) also attempted two replications on this allele writing:
We further conducted a replication analysis of the five significant CAC5 SNPs in two other independent Han Chinese samples (Li et al. 2015; Xu et al. 2015). The results showed that three SNPs (rs 7177192, rs11858113 and rs8040502) remained significant in Replication-1 for total brain volume and gray matter volume (Xu et al. 2015), but no association was detected in Replication-2 (Li et al. 2015) (Table S4).
It is very plausible that the genes that have regulated brain growth in our species further aid differences in brain morphology within and between races. This effect is seen mostly in Han Chinese girls. Shi et al (2016) write in the Discussion:
If this finding is accurate and can be further verified, it suggests that that [sic] after modern humans migrated out of Africa less than 100,000 years ago, the brain size may still be subject to selection.
I do believe it is accurate. Of course, the brain size could still be subject to selection; there is no magic field shielding the brain against selection pressure. Evolution does not stop at the neck.
So Shi et al (2016) showed that there were brain genes under recent selection in East Asians. What could the cause be? There are a few:
- Climate: In colder climates you need a smaller body size and big brain to survive the cold to better thermoregulate. A smaller body means there is less surface area to cover, while a larger head retains heat. It, obviously, would have been advantageous for these populations to have large brains and thus get selected for them—whether by natural or sexual selection. This could also have to do with the fact that one needs bigger eyes in colder environments, which would cause an increase in the size of the brain for the larger eyes, as well as being sharper visio-spatially.
- Intelligence: East Asians in this study showed that they had high levels of gray matter in the skull. Further, large brains are favored by an intermediately challenging environment (Gonzalez-Forero, Faulwasser, and Lehmann, 2017).
- Expertise: I used Skoyle’s (1999) theory on expertise and human evolution and applied it to racial differences in brain size and relating it to the number of tools they had to use which differed based on climate. Now, of course, if one group uses more tools then, by effect, they would need more expertise with which to learn how to make those tools so large brains would be selected for expertise—especially in novel areas.
- Vision: Large brains mean large eyes, and people from cold climates have large eyes and large brains (Pearce and Dunbar, 2011). Decreasing light levels select for larger eye size and visual cortex size in order to “increase sensitivity and maintain acuity“. Large eyeballs mean enlarged visual cortices. Therefore, in low light, large brains and eyes get selected for so one can see better in a low light environment.
Of course, all four of the examples below could (and probably do) work in tandem. However, before jumping to conclusions I want to see more data on this and how the whole of the system interacts with these alleles and these amino acid polymorphic sites.
In sum, there is now evidence for natural selection on East Asians (and not Africans or Europeans) that favored large brains, particularly gray matter, in East Asians with considerable sexual dimorphism favoring women. Four of the genes tested (MCPH1, ASPM, CDK5RAP2, and WDR62) are regulated by estradiol and contribute to sexual dimorphism in human and non-human primates (Shi et al, 2016). Though it still needs to be tested if this holds true for CASC5.
This is some of the first evidence that I have come across for natural selection on genes that are implicated in brain evolution/structural development between and within populations. It does show the old “Rushton’s Rule of Three“, that is, Mongoloids on top, Caucasians in the middle, and Negroids on bottom, though Caucasians were significantly closer to Africans than Mongoloids in the frequency of these derived alleles. I can see a HBDer going “They must be related to IQ”, I doubt it. They don’t ‘have’ to be related to IQ. It just infers a survival advantage in low light, cold environments and therefore it gets selected for until it reaches a high frequency in that population due to its adaptive value—whether spreading by natural or sexual selection.