The question of how different men's and women's brains are is one of the concerns that have been explored for decades. However, a research result was published that shows that the brains of men and women are not at all different, attracting attention. The research results, led by Dr. Liz Elliott, a neuroscientist at the Rosalind Franklin University of Medicine and Science, were published in the latest issue of Neuroscience and Biobehavioral Reviews, the journal of the International Society of Behavioral Neuroscience.
Elliott said, the brains of men and women are slightly different. The difference is not because of gender, but because of the size of the brain. The only obvious difference between male and female brains is the size of the brain.
In fact, women's brains are about 11% smaller than men's. This is because women's body size is that much smaller than men's. The smaller the brain, the slightly higher the ratio of gray matter to white matter and the higher the connection ratio between the left and right cerebral hemispheres appears. The brain has two types of cells. One is the gray matter with nerve cells, the other is the white matter that connects the gray matter and allows nerve cells to send signals to distant areas. However, it is not clear how the amount of gray matter relates to brain function, and it is not clear which benefit of the larger of either. Also, there is no correlation between brain size and intellectual ability. Men's brains are larger than women's, but across the world, there's no gender difference in IQ tests. There is no universal mark to distinguish between male and female brains
Dr. Elliott's team has fully analyzed hundreds of brain imaging studies over the past 30 years that have addressed gender differences in the brain. As a result, almost all studies involving thousands of experimental participants found no distinct differences in brain gender differences.
For example, the volume or thickness of a specific area in the cerebral cortex has often been reported to vary between males and females. However, it was found that the areas of difference differ greatly from study to study. In addition, the brain differences between males and females were not well-known among different population groups such as Americans and Chinese. This means that there are no universal markers that distinguish male and female brains across races.
The researchers refuted the previous view that men's brains are more centralized and the left and right brains work independently, while women's left and right brains are more connected and work harmoniously. In fact, according to the consensus of many previous studies, the difference in the range of left and right brain connections across the population was as small as less than 1%.
Scientists who support the gender difference in the brain have evidenced that men are more susceptible to brain damage disorders such as stroke, and that boys are diagnosed with autism four times more often than girls.
Existing research on gender differences is due to publication bias
However, Dr. Elliott argues that the gender differences in some brain-related diseases are not due to biological reasons, but rather due to prejudices or diagnostic criteria held by doctors. In the case of autism, for example, the definition of a disease itself is based on a boy.
The focus of this study is on functional magnetic resonance imaging (fMRI). This method has been widely used to find differences between men and women in terms of language, space, and emotion, as well as allowing you to see the brain regions that are activated when performing certain mental tasks.
However, a comprehensive analysis of the results of previous studies revealed that almost all specific brain regions that exhibit gender differences are not repeated throughout the study.
In response, Dr. Elliott argued, since the introduction of fMRI, studies that have found a significant gender difference have received great attention from other scientists and the media. In other words, it is explained that publication bias is common in the study of gender differences in the brain because this topic is of high interest. Publication bias is the effect of an experiment or research result on whether it is published or distributed.
Dr. Elliott said, the misconception that men and women have different brains has had a huge impact on the way men and women treat men and women. However, it is true that there are no universal features of the brain that have distinct differences between sexes.