Friday, July 26, 2019

All major brain regions are larger in men than women

The Left accuses the Right of being anti-science, but even the least educated conservative knows that men and women are different. While radical feminists keep propagandizing the gullible that gender differences are a myth perpetuated by the Patriarchy (email me the whens and wheres of our next secret meeting), real scientists are documenting the biological realities.

This meta-analysis of 126 studies shows very clearly that from birth to death males have bigger brains than females.  Men, on average, had greater total volumes on all of the following measures: intracranial, cerebrum, gray matter, white matter, cerebellum, and cerebrospinal fluid.  There was no major region that was larger in women. Depending on the study, male brains were between 8 and 13% larger.

The researchers also found significant volume differences in small regions.  Men averaged larger gray matter volumes in 33 areas, and 17 regions in females had more gray matter.  They also looked at gray matter density and reported that six regions in men were denser, while one area had greater density in women.

When regions are larger in males, they tend to be in the left hemisphere.  When areas are larger in women, they tend to be in the right one, so there is evidence of lateralization differences between the sexes.

Differences seem to emerge in regions known to be involved in language and emotion.  This makes sense since women tend to have a verbal advantage, and the sexes differ significantly in certain emotions like empathy.

Why do men have larger brains?  It looks like the studies did not adjust for body size, but even if you argue that male brains are bigger simply because their bodies are bigger, why are many areas larger in women?  Brains are very costly organs: they use a tremendous amount of energy, and big heads can kill mothers during birth.  Bigger brains are there for a reason.

After reading Arthur Jensen, I assumed men and women had identical average IQs, and that men were simply more diverse with a greater number of dullards and geniuses.  In recent years, evidence has emerged that, compared to females, male IQ peaks more slowly, and at a somewhat higher level (about four IQ points).  Researchers like Jensen supposedly missed this by focusing on samples of adolescents rather than fully developed adults.

Perhaps the 10% bigger brain gives men a little more mental horsepower.  It's a hazardous business to speculate why this would be.  Whatever the reason, the difference is real, and the feminists are wrong.

I imagine a skeptic will argue that perhaps the differences are due to environmental factors: male babies are fed and treated better, boys are given more intellectual stimulation, etc.  But why the differentiation where some regions are larger in men, while other areas are larger in women? And while the samples didn't allow a detailed study of age, it looks like the sex differences are in place among neonates.  Differences emerge early in life before many social factors are able to kick in.

UPDATE: Many of the regions with a male advantage are in the limbic system which is associated with aggression and sexual interests.  There are, of course, big sex differences in these traits.

UPDATE 2: As mentioned, areas that have greater volume in women tend to be in the right hemisphere which is associated with a proneness to negative emotions. While women are not more prone to anger than men, they do tend to be more anxious and depressed.

Sunday, July 21, 2019

A note on Lynn's "Race Differences in Psychopathic Personality"

Lance Welton at does a nice job of summarizing Richard Lynn's brand new book Race Differences in Psychopathic Personality

I won't repeat Lance's points, but I see in the comments that some people are claiming that the racial differences are explained in terms of the environment. This, of course, is the standard explanation--the only one you will get in sociology class, if the instructor is honest enough to acknowledge that the group differences indeed exist.

There are two obvious reasons to think the racial gaps (psychopathy running from high to low in this order: black, Native American, Hispanic, white, Asian) are at least partially due to genetic differences: 1) the differences are basically universal–found historically (Lynn cites over 700 studies conducted from the 19th century to now) and all around the world, and 2) psychopathy is highly heritable, similar to general intelligence. Therapists find it practically impossible to treat.

As Arthur Jensen explained, it is reasonable to conclude that if genes explain 70% of the variation in a trait, they likely explain 70% of group differences. The only reason why the commonsense belief that “What You See is What You Get” is not popular today but “People Are Not Themselves But Their Surroundings” is assumed to be true is that we have been propagandized by armies of full-time storytellers for more than a century.

I do take issue with conceptualizing psychopathy as a disorder, as if human nature is naturally good, and antisociality suggests a brain that is not working properly. I’m not criticizing Lynn but psychiatry. Exploitativeness is a regrettable but perfectly healthy and natural supertrait.  Psychiatrists want to turn all problematic behaviors into forms of mental illness, which is just silly. Evolution has designed us to thrive and to be strong, not to be burdened on every side by illness and weakness.  Mainstream behavioral science portrays us--the descendants of nature's winners--as naturally frail.  Complete BS.

Wednesday, July 17, 2019

Which ethnic groups think astrology is scientific?

It is important for America that we have people who understand and value science.  The General Social Survey asked people residing in the US, "Would you say that astrology is very scientific, sort of scientific, or not at all scientific?"  Anyone who understands science would not say astrology is scientific, even if they otherwise like it. 

Let's look at the percentage who say astrology is very or sort of scientific listed by ethnic group (sample size = 6,873):

Percent who say astrology is scientific

Black  53.1
Mexican  50.6
Asian Indian  47.4
Puerto Rican  46.4
American Indian  45.1
Filipino  42.7
Spanish  41.2
Norwegian  38.5

All Americans  36.3

Chinese  35.5
Italian  35.1
Portuguese  34.3
Arab  32.1
Irish  31.1
French Canadian  30.8
Polish  29.9
French  29.5
Dutch 29.2
German  28.9
Japanese  28.5 
Czech  27.7
Swiss  27.5
Russian  27.0
Greek  25.0
Scottish  24.3
Jewish  23.8
English  23.5
Danish  21.1
Swedish  15.1

Blacks, Hispanics, and American Indians top the list, but some high IQ ethnic groups are toward the top as well; namely, Asian Indians, Norwegians, and Chinese.  Setting aside the Norwegians, there is a tendency for northwestern Europeans to fall to the bottom of the list.  These groups are more skeptical and seem to understand better what it means to be scientific.

Sunday, July 14, 2019

Why would an animal programmed to survive and reproduce care so much about right and wrong?

In a recent post, I critiqued Richard Wrangham's theory of why humans are so much less violent than our cousins, the chimpanzees.  In The Goodness Paradox, he also attempts to explain why we have a strong moral sense.  It's strange for an animal designed to outcompete others through survival and greater reproductive success to care so much about abstract concepts of right and wrong.

He hypothesizes that human society changed fundamentally when men developed the language to coordinate control over other members of the group.  While apes sometimes gang up and beat or kill a single, obnoxious ape, they don't plan it out ahead of time.  Men gained a tremendous tool when they began to conspire as a group of five or six against one.  They could discuss the idea, plan a surprise attack, and kill the offender with little danger to themselves.  Sometimes the murder wasn't necessary: A rumor could be floated and the troublemaker might be convinced to change his ways.

Wrangham claims that men expanded their control to all members of the community so that everybody was were in fear of their ability to conduct a surprise attack against them.  Over evolutionary time, humans were selected for their ability to please the men who had this power over them.  Extremely selfish, exploitative people were weeded out.  A person who treated everyone well was unlikely to displease elders, so prosociality became a more and more common trait.  And while I didn't find Wrangham clear on this point, I think moral values gradually developed as a reflection of the prosocial personalities that were becoming common.

According to Wrangham, selection has been more successful at producing people oriented toward having a good reputation and appearing moral rather than creating humans of deep, genuine integrity and principle.  After all, we are still programmed to care about our own reproductive interests.

I would return to my earlier criticism: In 2019, some groups seem to have much higher rates of prosociality than others.  For example, a quick look at the Corruption Perceptions Index reveals that Denmark has very little public corruption compared to Somalia. How does Wrangham help us explain the enormous gulf between the two countries?  He doesn't.  He presents the image of all human groups across the globe being identical in terms of genes that contribute to cooperativeness.  I suppose he would say that evolutionary biology tells the story up until the day before yesterday, but now it's irrelevant: It's all sociology now.  Not credible. 

Saturday, July 13, 2019

Who is more likely to be unfaithful: high- or low-income men?

The liberal instinctively idealizes and sympathizes with the man at the bottom of society (although liberals are becoming so crazy these days, it's getting hard to characterize them coherently.)  By contrast, a certain brand of conservative might be tempted to idealize the successful man: Effort or perhaps good genes get a guy to the top.

Reality seems a little more complicated than that.  Brains and discipline help a person rise, but so can Machiavellianism.  I suspect that successful people tend to be a mixed bag.

Let's test the idea that there is moral virtue in successful people by looking at marital infidelity.  I divided personal income into 5 levels and created graphs for white and black men (sample sizes = 7,959 and 894):

Black Men

White Men

Among black males, you see a spike in cheating among the highest income group.  It's a smaller increase among high-earning white males.

So successful men are a little more likely to be unfaithful. You might attribute this to the greater attractiveness that comes with money or to greater social opportunities, but whatever the case, there is no indication here that successful men are more moral than others.  It's important that we stick to reality and not ideology.

Wednesday, July 10, 2019

Richard Wrangham works hard to explain the violence gap we don't care about

Urban Americans worry quite a bit about violence in their cities.  Many of these places will rack up hundreds of homicides per year.  Urban black men face a pretty decent chance of being murdered.  So it was weird to read Richard Wrangham's new book The Goodness Paradox with its central claim that humans are very peaceful.

How could he have this view?  Well, he has studied chimps for decades.  Contrary to stories told by liberal primatologists in the 1960s, it turns out that chimps are mean bastards.  If you stuffed 200 of them into Boeing 737, by the end of the flight many would be murdered.  The human homicide rate is a tiny fraction of that seen among chimpanzees.

Wrangham then sets out to develop a theory to explain why we are so slow to lose our cool and attack others.  He claims that when our ancestors developed the ability for fairly sophisticated language about 300-500k years ago, men in a group began to handle their antisocial members by plotting to murder them.  Chimps will sometimes gang up on a cantankerous alpha and take him out, but it is spontaneous.  No planning is involved.

Men gained great power over individuals by using premeditated, coalitionary aggression against not only bullies but eventually against all non-conformists.  Over evolutionary time, this selected for humans who were motivated to get along with others and who were particularly interested in pleasing tribal elders--the men who had the power to kill them if they become sufficiently annoyed.

In developing his theory, Wrangham did exactly what I expected from a PC biologist: He avoids discussions of why human groups currently vary so much in their levels of homicide.  Some educated person reading his book wants to know why his neighborhood is so much safer than the black neighborhood on the other side of town. The homicide rate in Colombia, for example, is scores of times higher than in Japan.  Why?  Wrangham is silent on this type of issue.  He makes it sound like humanity has experienced the exact same selection pressures for hundreds of thousands of years, and that we all arrive at 2019 exactly the same in terms of genetic propensity for violence.  He admits that the speed of selection probably increased in more recent millennia, but is silent about what that means.

Wrangham also fails to discuss the scholarship of Greg Cochran, Henry Harpending, and Peter Frost which suggests that pacification of some human groups has happened over the past few thousand years. I guess I would be silent on such topics, too, if I valued my lofty perch at the Department of Human Evolutionary Biology at Harvard University.

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