Peer reviewed study on PLOS ONE confirms through fmri of whole-brain lateralization (as compared to past studies of local specialized areas which this refutes) that the Left-Brain vs. Right-Brain Hypothesis is false - including between genders.

According to the study, "An Evaluation of the Left-Brain vs. Right-Brain Hypothesis with Resting State Functional Connectivity Magnetic Resonance Imaging", there is no hemisphere specialization when tested by fmri of whole brain lateralization, including left brain right brain orientation between genders. This means that we as humans do not have specialized usage from either hemisphere of the brain. While major functions tend to be found in specific areas, there is no bias as to which side has more connectivity through lateralization.

This also means that women are no more "left brain oriented" than men are "right brain oriented", which has been suggested and supported by past studies of local specialized areas in each hemisphere.

"...[W]e saw no differences in functional lateralization with gender. These results differ from prior studies in which significant gender differences in functional connectivity lateralization were reported. This may be due to differing methods between the two studies, including the use of short-range connectivity in one of the former reports and correction for structural asymmetries in this report. A prior study performing graph-theoretical analysis of resting state functional connectivity data using a predefined parcellation of the brain also found no significant effects of hemispheric asymmetry with gender, but reported that males tended to be more locally efficient in their right hemispheres and females tended to be more locally efficient in their left hemispheres."

"...[W]e demonstrate that left- and right-lateralized networks are homogeneously stronger among a constellation of hubs in the left and right hemispheres, but that such connections do not result in a subject-specific global brain lateralization difference that favors one network over the other (i.e. left-brained or right-brained). Rather, lateralized brain networks appear to show local correlation across subjects with only weak changes from childhood into early adulthood and very small if any differences with gender."

I saw this in the news a few days ago and didn't realize the significance of it until finishing chapter two in Michael Gazzaniga's book "Who's in Charge?: Free Will and the Science of the Brain" where he describes the first study he conducted on left brain right brain localization in patients who had epilepsy, whose seizures were alleviated by the severing of the corpus callosum. The Wikipedia page on "Split-brain" lists that more research is being done on hemisphere specialization to confirm left brain right brain theories, and the Wikipedia page for "Lateralization of brain function" claims that men are "more lateralized" than women. I'm trying to make a list of Wikipedia pages that probably need to be updated, and I'm working on re-writing sections on both "Split-brain" and "Laterlalization of brain function".