In this new study, structural MRI data were collected on 672 45-year-old participants in the Dunedin Study, a population-representative longitudinal cohort. Twelve percent were classified as having life-course persistent (LCP) antisocial behavior, while 23% were categorized as having adolescent-limited (AL) antisocial behavior.
These are classifications developed by criminologist Terrie Moffitt back in the 90s who hypothesized that the LCP pattern is characterized by genetically-rooted, neurological deficits, while the AL pattern is explained more by social factors experienced during adolescence.
The authors found that the LCP group, compared to the low antisocial behavior group, had a significantly smaller mean global surface cortical area and lower mean cortical thickness. The effect sizes were of moderate size for the cortical area and of smaller magnitude for the cortical thickness.
The cortical measures for the AL group were not significantly different than those for the low antisocial group.
The authors concluded that the results for both the LCP and AL groups were consistent with Moffitt's theory of antisocial behavior.
Showing posts with label Brain. Show all posts
Showing posts with label Brain. Show all posts
Thursday, March 05, 2020
Wednesday, September 11, 2019
Another study showing that you can tell someone's IQ by looking at his brain (especially if he is a she)
I recently reported on researchers who were able to explain 95% of the variation in general intelligence based on the morphology of the brain. Just amazing. Now I run across another new study--they keep pouring out--conducted by Chinese researchers that found very strong correlations between the functional connectivity of various regions of the brain and intelligence.
They mapped out thousands of nodes and the connections between nodes and found that eight connections were important for males, and 13 different connections that were crucial for predicting female IQ. Smart women have differently wired brains than smart men. Smart women benefitted from efficient overall brain connectivity, while smart men tended to have better wiring in specific regions of the brains.
The connections identified for women predicted female IQ more powerfully than "male" connections predicted male IQ. They explained 72% of the variation in intelligence for women and 46% for men. You really can predict someone's IQ by looking at the brain, but you've got to look at different networks depending on whether it's a man or woman. SEX DIFFERENCES MATTER!
They mapped out thousands of nodes and the connections between nodes and found that eight connections were important for males, and 13 different connections that were crucial for predicting female IQ. Smart women have differently wired brains than smart men. Smart women benefitted from efficient overall brain connectivity, while smart men tended to have better wiring in specific regions of the brains.
The connections identified for women predicted female IQ more powerfully than "male" connections predicted male IQ. They explained 72% of the variation in intelligence for women and 46% for men. You really can predict someone's IQ by looking at the brain, but you've got to look at different networks depending on whether it's a man or woman. SEX DIFFERENCES MATTER!
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.
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, April 14, 2019
Data: If Taleb is right that IQ is a BS measure, why do higher scorers have big brains? And why the perfect racial rankings?
A 2015 meta-analysis of 88 studies found that the correlation between human brain volume and intelligence is .24, a small-to-moderate size relationship. In new research that re-analyzed the data from the 2015 study, the authors showed that the strength of the link depends on how well IQ is measured and the degree to which studies include a full range of values for brain volume and IQ (For example, if only college students are included, many lower IQ people will be excluded, and this will shrink the correlation.)
Based on their analysis, the researchers estimated that the true brain volume/IQ correlation is around .40 -- a fairly strong correlation.
Keep in mind that many researchers have reported racial differences in brain volume that match up with IQ differences. Rushton and Ankney (2009) summarized the research. For example, Beals et al. (1984) measured the endocranial volumes of close to 20,000 skulls from around the world. The Asian-black gap was reported to be a roughly 150 cubic centimeter advantage for Asians.
If IQ is BS measure like Nassim Taleb says, why do high scorers have big brains?
Based on their analysis, the researchers estimated that the true brain volume/IQ correlation is around .40 -- a fairly strong correlation.
Keep in mind that many researchers have reported racial differences in brain volume that match up with IQ differences. Rushton and Ankney (2009) summarized the research. For example, Beals et al. (1984) measured the endocranial volumes of close to 20,000 skulls from around the world. The Asian-black gap was reported to be a roughly 150 cubic centimeter advantage for Asians.
If IQ is BS measure like Nassim Taleb says, why do high scorers have big brains?
Monday, December 03, 2018
Study reveals an evil secret: You can look at a brain and tell whether it is a man or woman
In this new study, the researchers use MRIs to measure examines the brains of a fairly large sample (N = 1,300) of incarcerated men and women. They use machine learning to classify sex. They are able to predict whether the brain is of a male or a female with 93% accuracy. This finding replicated what the authors found earlier with a healthy, non-incarcerated sample.
Now, how are these findings possible when every good person knows men and women have interchangeable brains, and to think otherwise makes you a Neanderthal?
The researchers also found that there were certain brain regions that are highly differentiated: the orbitofrontal and frontopolar regions, larger in females, and the anterior medial temporal regions, which are larger in males. Reduced functioning in the orbitofrontal region has been linked to aggression and violence. The anterior temporal cortex is closely connected to limbic and paralimbic structures that influence social and emotional processing, traits associated with disinhibition and violent/aggressive behavior.
The frontopolar and orbitofrontal regions are also crucial in moral judgment and planning behavior. The temporoparietal junction is also important for execution of attentional shifts required for perspective-taking, theory of mind, and empathy.
This is also consistent with the behavioral deficits males show with respect to interpersonal skills, empathy, threat sensitivity, disinhibition, and aggression.
Conclusion: Grandma was right--men and women are (biologically) different.
Subscribe to:
Posts (Atom)
Are gun owners mentally ill?
Some anti-gun people think owning a gun is a sign of some kind of mental abnormality. According to General Social Survey data, gun owners ...
-
Which factor reduces family size the most? Below are the standardized OLS regression coefficients for a sample of whites ages 40-59: Stand...
-
More on trust: As a follow-up to the last post, I wondered about the level of trust in Asian and Muslim countries. Based on World Values Sur...
-
The plot thickens: As a follow-up to the last post, I wanted to see if the risk of arrest varies by hair color. I found that people with red...