Sorry, guys who blame their masculine brains for stupid things they say/do/think, science has some bad news for you: it's not all in your skull filling after all.

According to a new study released in the Proceedings of the National Academy of Sciences, "Sex Beyond the Genitalia: The Human Brain Mosaic," MRI scans of 1,400 brains showed that if you look at the overall structure of men and women's brains they are not very different.

Sure, certain areas have differences based on the person's sex, but, according to the Associated Press, "an individual brain only rarely has all 'male' traits or all 'female' traits." Instead, they found "extensive overlap" between the grey matter in female and male brains, referring to the resulting image as a kind of "mosaic."

"Our results demonstrate that regardless of the cause of observed sex/gender differences in brain and behavior (nature or nurture), human brains cannot be categorized into two distinct classes: male brain/female brain," the authors wrote.

Some traits are more common in men, some in women and some are found in both, proving that you can't really divide brains into two easy-to-distinguish, sex-based groups. The two researchers from Tel-Aviv University studied the MRI scans for traits like tissue thickness or volume in different parts of the brain, zeroing in on traits that showed the biggest differences between the sexes. What they found was that it was "much more common for an individual to score in both the male and female zones than to show a lineup that indicated only one sex or the other."

Just to back up their findings, the researchers also applied their approach to analyze psychological and behavioral scores from two earlier studies involving 5,000 subjects, finding similar results. The bottom line: "human brains do not belong to one of two distinct categories [male of female]."