© collective evolutionA recent study proves that "all male" and "all female" brains are rare and that most people are in the middle.
A recent study published in the Proceedings of the National Academy of Sciences further challenged the assumed differences between the sexes by studying the brains of 1,400 males and females to determine if there really are distinct differences.
In a nutshell, the study:
"provides biological support for something that we've known for some time—that gender isn't binary."In the past, dozens of studies have looked at male and female brains and found several characteristics that were an indicator that the person was absolutely one sex or the other.
For example a study conducted by Israeli researchers found differences in the developing fetus as early as 26 weeks into the pregnancy by using an ultrasound scanner. They found that the corpus callosum— the bridge of nerve tissue that connects the hemispheres of the brain—was thicker in female fetuses than males. Adult brain scans in other studies have shown that this bridge remains thicker in females even as adults.
However, new research shows that most people tend to have a mix of both male and female features and that the rigid gender classifications in the past based on brain characteristics are meaningless.
Researchers studied 1,400 MRI images of different people from the ages of 13 to 85 and examined the size of different brain regions, as well as the connections between them. It's the first study to search for sex differences across the entire human brain.
After finding that 29 regions in the brain had some differences, only 0 to 8 percent of the people were determined to have "all male" or "all female" brains. Daphna Joel, a psychologist at Tel-Aviv University involved in the study, said:
"Most people are in the middle."In fact, up to 53% showed a total mix of supposedly male and female characteristics. The study proves that previous notions of huge differences in the minds of the sexes have been wrong in asserting that these are absolute.
Bruce McEwen at the Rockefeller University, who reviewed and edited the study, told New Scientist:
"We are beginning to realise the complexity of what we have traditionally understood to be 'male' and 'female', and this study is the first step in that direction. I think it will change peoples' minds."
"Most people are in the middle." Doesn't tell anyone much about anything. The transgender studies have come up with a much more informative way of presenting the information. There isn't a bell curve where the population of male and female exist on either side of the middle.
There would appear to be 2 separate curves, with few being all on one of the curves (or bell curves). You can have a brain wired female, female traits but in a predominately male body (XY), a sexual preference of female companionship but see yourself as a female deep inside with the external look of a male.
And each of these 5 aspects (Chromosomal Inheritance, Physical appearance, Brain Sex, Sexual Orientation and Gender Identity are not binary (on or off) but to degrees from say...1 to 10.
Isn't nature wonderful to have so varied an output?
It's too bad that societies have developed (or bred/cultivated/culled/killed) such strict all male or all female stereotype and left the 3rd Sex out of the equation altogether.