Common belief dictates that the brains of men and women are distinct from each other. However, a new study shows that the existence of what's been termed "male" and "female" brains is a myth and that human brains cannot be exclusively classified into gender-based categories.
To determine if there are structural differences between the brains of men and women, researchers, led by Daphna Joel who heads the Psychobiology program at Tel Aviv University, studied MRI scans of 1,400 individuals. Comparing the characteristics of the different parts of the brain, the researchers found many overlaps or similarities between the two genders.
They focused on the areas that showed the least similarities and created a male and female continuum where they designated one end to be the "male end" and the other to be the "female end." They found that those who fell on consistenly male or female categories ranged from 0 percent to 8 percent. On the other hand, those who displayed both male and female characteristics ranged from 23 percent to 53 percent.
"Our study demonstrates that although there are sex/gender differences in brain structure, brains do not fall into two classes, one typical of males and the other typical of females, nor are they aligned along a 'male brain-female brain' continuum," the study authors wrote.
The human brain contains "a unique mosaic of features, some of which may be more common in females compared with males, others may be more common in males compared with females, and still others may be common in both females and males," the authors said.
The researchers also investigated data regarding male and female behavior. They discovered that men and women displayed a mixture of behaviors, and that those who showed stereotypically male or stereotypically female traits comprised only 0.1 percent of the study participants.
"There is no sense in talking about male nature and female nature," Joel told Science. "There is no one person that has all the male characteristics and another person that has all the female characteristics. Or if they exist they are really, really rare to find."
The study was published online Nov. 30 in the Proceedings of the National Academy of Sciences.
