In this new study, the researchers use MRIs to measure examines the brains of a fairly large sample (N = 1,300) of incarcerated men and women. They use machine learning to classify sex. They are able to predict whether the brain is of a male or a female with 93% accuracy. This finding replicated what the authors found earlier with a healthy, non-incarcerated sample.
Now, how are these findings possible when every good person knows men and women have interchangeable brains, and to think otherwise makes you a Neanderthal?
The researchers also found that there were certain brain regions that are highly differentiated: the orbitofrontal and frontopolar regions, larger in females, and the anterior medial temporal regions, which are larger in males. Reduced functioning in the orbitofrontal region has been linked to aggression and violence. The anterior temporal cortex is closely connected to limbic and paralimbic structures that influence social and emotional processing, traits associated with disinhibition and violent/aggressive behavior.
The frontopolar and orbitofrontal regions are also crucial in moral judgment and planning behavior. The temporoparietal junction is also important for execution of attentional shifts required for perspective-taking, theory of mind, and empathy.
This is also consistent with the behavioral deficits males show with respect to interpersonal skills, empathy, threat sensitivity, disinhibition, and aggression.
Conclusion: Grandma was right--men and women are (biologically) different.