Pour ceux qui auraient des doutes pourquoi les pays développés font de la discrimination positive  : quota parité nomination recrutement, des actions spécifiques pour les filles et les garçons, des différences sexuées dans les normes, les hiérarchies  pour augmenter le nombre de filles et/ou femmes cette construction sociétale féministe nous montre les différences sexuées.

 

https://phys.org/news/2022-01-universal-sex-differences-adolescents-career.html

A new analysis by David Geary at the University of Missouri and Gijsbert Stoet at the University of Essex in the United Kingdom finds career aspirations from nearly 500,000 adolescents shows consistent sex differences across 80 nations, suggesting biologically-influenced preferences can play a role in gender segregation in the workplace later in life. The researchers also found a tendency for larger differences to appear in gender-equal countries, such as Finland, Norway or Sweden.

"Sex differences in career choices and outcomes are often blamed on social factors, such as stereotypes and bias," said Geary, Curators Distinguished Professor of Psychological Sciences in the MU College of Arts and Science. "Our study shows that many of these differences are universal and larger in equalitarian societies, suggesting there are biological influences on peoples' occupational preferences."

Geary said this study confirms what the researchers call a "gender-equality paradox," or where increased levels of gender equality in a country lead to larger sex differences, such as in occupational aspirations.

"The sex differences in interest in things- and people-oriented occupations were not only found throughout the world, but mirror those found in a study done more than 100 years ago," Geary said. "The results are consistent across time and place, in keeping with inherent sex differences that make some activities more attractive to adolescent boys than girls and others more attractive to girls than boys."

Using data from the 2018 Programme for International Student Assessment (PISA), the analysis showed more boys than girls in each country—about a 4-to-1 ratio—wanted to go into "things-oriented" occupations, such as a carpenter, engineer or mechanic, while more girls than boys—about a 3-to-1 ratio—wanted to go into a "people-oriented" occupation, such as a doctor or teacher.

For example, in the U.S. and U.K., researchers found more than five boys for every girl aspired for a things-oriented occupation. That ratio was even greater in Sweden, where more than seven boys for every Swedish girl aspired to a things-oriented occupation. On the other hand, in countries such as Morocco or the United Arab Emirates, where women experience less empowerment in politics, education, or health, the ratios were typically lower, or around two boys for every girl.

"Teenage boys and girls differ considerably in what they expect to work on at around age 30," said Stoet, psychology professor at University of Essex. "The effects are largest in the countries where most people would expect the smallest differences. Their choices are likely a reflection of deeply built-in tendencies we see all over the world, but which express them most strongly in countries where adolescents are least constraint by economic limitations."

 

https://www.sciencedirect.com/science/article/pii/S2213158217301195

The question of whether there are biological differences between male and female brains is a fraught one, and political positions and prior expectations seem to have a strong influence on the interpretation of scientific data in this field. This question is relevant to issues of gender differences in the prevalence of psychiatric conditions, including autism, attention deficit hyperactivity disorder (ADHD), Tourette's syndrome, schizophrenia, dyslexia, depression, and eating disorders. Understanding how gender influences vulnerability to these conditions is significant. Diffusion magnetic resonance imaging (dMRI) provides a non-invasive method to investigate brain microstructure and the integrity of anatomical connectivity. Generalized q-sampling imaging (GQI) has been proposed to characterize complicated fiber patterns and distinguish fiber orientations, providing an opportunity for more accurate, higher-order descriptions through the water diffusion process. Therefore, we aimed to investigate differences in the brain's structural network between teenage males and females using GQI. This study included 59 (i.e., 33 males and 26 females) age- and education-matched subjects (age range: 13 to 14 years). The structural connectome was obtained by graph theoretical and network-based statistical (NBS) analyses. Our findings show that teenage male brains exhibit better intrahemispheric communication, and teenage female brains exhibit better interhemispheric communication. Our results also suggest that the network organization of teenage male brains is more local, more segregated, and more similar to small-world networks than teenage female brains. We conclude that the use of an MRI study with a GQI-based structural connectomic approach like ours presents novel insights into network-based systems of the brain and provides a new piece of the puzzle regarding gender differences.

The question of whether there are biological differences between male and female brains is a fraught one, and political positions and prior expectations seem to have a strong influence on the interpretation of scientific data in this field (Abramov et al., 2012, Fairchild et al., 2016, Ingalhalikar et al., 2014, Joel, 2011, Joel et al., 2015, Xu et al., 2015).

Gender differences in human brains is an important topic because the prevalence of psychiatric conditions varies between the genders; such differences have been observed in autism (much more common in males) (Baron-Cohen, 2009, Baron-Cohen et al., 2005), attention deficit hyperactivity disorder (ADHD, much more common in males) (Arnett et al., 2015), Tourette's syndrome (much more common in males) (Yang et al., 2016), schizophrenia and dyslexia (more common in males) (Arnett et al., 2017, McGrath et al., 2008), depression (more common in females) (Goldstein et al., 2014, Schuch et al., 2014, Shansky, 2009), and eating disorders (much more common in females) (Lipson and Sonneville, 2017). Understanding how gender influences vulnerability to these conditions is, therefore, a significant question.

Previous studies found strong group differences between male and female brains; despite comparable findings, the authors of these studies interpreted the results in almost polar opposite fashions (Ingalhalikar et al., 2014, Joel et al., 2015, Szalkai et al., 2015). One structural connectivity study interpreted these group differences as the basis for gender differences in cognition (Ingalhalikar et al., 2014). They defined the structural connectivity networks across the brains of 428 males and 521 females using diffusion tensor imaging (DTI). They subsequently analyzed these networks using a variety of statistical measures of regional and global connectivity and compared the results between males and females. They found that on average, females had greater connectivity between hemispheres than males, while males had greater connectivity within each hemisphere. Males also showed, on average, greater local connectivity and concomitantly increased modularity in the network.

A different study on the volume of brain regions downplayed these differences entirely and instead emphasized the inherent variability within genders, concluding that there was no such thing as a “male brain” or a “female brain” (Joel et al., 2015). They analyzed the MRI scans of 169 females and 112 males and segmented them into 116 regions using a standard brain atlas. By analyzing how much warping was required to map each brain onto a reference template, it was possible to compare the relative gray matter volume of all these regions across the two genders. From this group comparison, the 10 regions showing the largest gender differences were chosen for subsequent analyses. The researchers found statistically significant group differences between males and females in gray matter volume across many brain regions. A recent meta-analysis of 167 studies confirms consistent gender differences in many brain areas between men and women (Ruigrok et al., 2014).

Joel et al. (2015) went on to ask a more interesting question: across those ten regions, how “male” or “female” were the structures of individual brains? This is where subjectivity comes in – there are many ways to analyze these data, and the authors chose arguably the most simplistic and extreme one, which enabled them to draw the conclusion that male and female brains are not categorically different. They reported that 35% of brains showed substantial variability, and only 6% of brains were internally consistent. Importantly, they chose to classify only those subjects showing extreme male or female values for all ten regions as internally consistent.

Another group published several studies that showed striking sex differences among human connectomes using graph theoretical parameters; they revealed clear differences and suggested the superiority of female brains (Szalkai et al., 2015). They also accounted for possible artifacts caused by statistical size differences between male and female brains. The graph theoretical parameters of 36 large-brained females and 36 small-brained males were compared, and the differences remained statistically significant.

Our results establish that teenage male brains exhibit better intrahemispheric communication and teenage female brains exhibit interhemispheric communication. Our results also suggest that the network organization of teenage male brains is more local, more segregated, and more similar to small-world networks than teenage female brains. We conclude that MRI studies using a GQI-based structural connectomic approach like ours can offer novel insights into the network-based systems of the brain and provide a new piece of the puzzle regarding gender differences.

 

https://www.studyfinds.org/men-women-brains-different/

Mice aren’t humans,” Shah notes. “But it’s reasonable to expect that analogous brain cell types will be shown to play roles in our sex-typical social behaviors.”
Women’s reproductive cycles also lead to hundreds of differences

The study analyzed four tiny structures that help the animals reproduce and offspring survive. Other mammals, including humans, share these structures as well. They program a males’ quick determination of a stranger’s sex, females’ receptivity to mating, and maternal protectiveness.

Researchers extracted tissue from the animals which contained neurons enriched with sex hormones. Genes are the blueprints for proteins, which do virtually all of a cell’s work. Activation levels – the rate at which genes copy and convert information – determine its functions.

Women’s estrogen levels and those of another hormone, progesterone, wax and wane on a roughly monthly basis, like phases of the moon.
The link between these genes and diseases

Some catalogued genes are risk factors for brain disorders that are more common in either men or women, depending on the particular gene. Autism spectrum disorder is four times more common in men. Of 207 genes which confer high risk, 29 are more active in males, compared to just 10 in females.

Scientists found genes with a link to Alzheimer’s and multiple sclerosis, both of which afflict more women, in an overexcited state among female mice. The researchers speculate males and females need different genes to be working harder. A mutation in a gene that needs high activation may do more damage than one that is just sitting around.

“These primal behaviors are essential to survival and reproduction,” the professor says, “and they’re largely instinctive. If you need to learn how to mate or fight once the situation arises, it’s probably already too late. The evidence is pretty clear that the brain isn’t purely a blank slate just waiting around to be shaped by environmental influences.”

Determining what makes mice tick also required separating surrounding cells and examining their genetic contents, one at a time.

“This is probably just the tip of the iceberg,” Prof. Shah concludes. “There’s likely to be many more sex-differentiated features to be found in these and other brain structures, if you know how to look for them.”

 

https://consumer.healthday.com/screen-time-linked-to-autism-spectrum-disorder-in-boys-2656510527.html

"The main finding of this study was that, among boys, a statistically significant association was found between longer screen time at 1 year of age and autism spectrum disorder at 3 years of age, irrespective of potential maternal maltreatment or predisposition to autism spectrum disorder at 1 year of age," the authors write.

 

https://equalityforboysandmen.org/even-more-interesting-facts-about-testosterone-from-harvard-professor-carole-hooven/

A man’s hormonal response to becoming a father depends heavily on his culture and the amount of time he interacts with his children. For example, dads in the Hadza foragers of Tanzania (who are generally socially monogamous) frequently hold, feed, and play with their babies, while dads in the neighboring Datoga pastoralists (who practice polygyny) are more likely to leave this to the moms and other caregivers. You can guess which dads have the lowest T levels—the Hadza. The T levels of the Hadza dads were found to be almost 50 percent lower than their childless fellows, while the T levels of the Datoga dads were no different from Datoga men without kids.

Physically interacting with young children, doing things like feeding, playing, carrying, or changing diapers, is associated with a T drop in dads. And in many situations, a dad’s focus on his family will increase his overall reproductive success. (p. 198)

Men’s violence

Across distant times and places men murder and physically and sexually assault vastly more than women do. Men commit about 90 to 95 percent of all murders worldwide, and they most often kill other men. (p. 163)

Among the hunter-gatherer populations remaining today, the sex differences in homicide rates are comparable to those in the rest of the world: men commit almost all murders, mostly against other men. (p. 165)

Who kids play with

Before the age of about two or three years old, kids toddle around with little attention to gender. But for most kids, as soon as they come to understand that they are a boy or girl, in diverse cultures all over the world, they begin to gravitate toward their own kind. The overwhelming majority of children’s playmates are members of their own sex, and this gender segregation peaks around the ages of eight to eleven. Younger kids appear to be drawn to the sex that is playing in a way that they find appealing, leading to fairly loose patterns of segregation. But as kids develop, playing with one’s own sex, no matter what they are doing, becomes more important. (p. 94)