Scientifically speaking, there is no distinction between a male and female brain. Researchers analyzed over 1,400 MRI brain scans and found that the biological characteristics that define males from females do not manifest in the brain.
Rather, the study found that the brain is a mixture of both masculine and feminine features. This was the first time a study looked at the human brain as a whole and determined if it has two distinct types.
In their analysis, the researchers found that both MRI brain scans of men and women do not have distinct differences when it comes to gray matter (neurons), white matter (connect neurons together) and other brain connections.
Further analysis of two past studies covering actions, attitudes and personality traits found that people seem to have a mixture of both female and male traits. Out of over 5,500 participants in the two past studies, only 0.1 percent showed stereotypically male or female behaviors. The researchers said if there are indeed individuals with an all-male traits or all-female traits, they are very, very rare.
"Each person possesses a unique mosaic of characteristics: some more common in females compared to males, some more common in males compared to females, and some common in both," said Tel-Aviv University professor and psychologist Daphna Joel, the study's lead author.
Neuroscientist Larry Cahill from the University of California in Irvine agreed with the study findings that the human brain is a mixture of both female and male traits. However, this biological truth doesn't exclude how the brains of two sexes work differently.
"[There is] a mountain of evidence proving the importance of sex influences at all levels of mammalian brain function," said Cahill, who wasn't involved in Joel's study.
The researchers concluded despite the appearance of gender differences in the MRI scans, over all, the human brains do not fall into either one of the two distinct categories. The findings revealed the extensive overlapping of both male and female traits for the grey and white matter and brain connections.
The study was published in the journal Proceedings of the National Academy of Sciences on Nov. 30.