New Stanford Study finds huge differences between male and female brain activity

Link to the study: https://www.pnas.org/doi/10.1073/pnas.2310012121

Link to article on the study: https://www.psychologytoday.com/us/blog/sax-on-sex/202405/ai-finds-astonishing-malefemale-differences-in-human-brain

The new study dispels these two commonly held beliefs:

1. Male and female psychological differences are solely due to cultural differences
2. Although male and female psychologies differ on average, they rest along a continuum where some women may have male-like psychologies and some men may have female-like psychologies. There is no clear line distinguishing male and female brain activity.

To start, I know some of you have seen studies in the past claiming stuff like "the only notable difference between male and female brains is that male brains are slightly bigger." However, keep in mind that these conclusions were formed when we didn't have the powerful AI/ML techniques that we have now. Studies in the past relied on subjective human visual perception or less refined AI/ML techniques.

With that out of the way, let's begin to dive into the meat of the study.

The researchers took fMRI of the "resting brain activity" of both men and women.

Here is a T-SNE visualization of the results: https://imgur.com/a/t9VyI2v

As you can see, there is NO continuum. Male data points and female data points are pretty solidly grouped into 2 separate clusters. This disproves point #2. I'll discuss further differences later.

Let's now address point #1. Suppose that male and female psychological differences are solely due to cultural differences (e.g. the differences in how boys and girls were raised, media, etc.).

To preface on my argument, most people will agree culture is not some immutable law that is imposed by society uniformly and consistently from individual to individual. Even more so for individuals that live in "progressive" cultures. The study also mainly takes participants from "progressive" states like California, New York, and Germany where gender role stratification is minimized (though still present).

What we should expect, if differences in psychology were purely cultural, is that there should exist a certain portion of men and women (the ones who are less affected by gender role ideology) who have closer psychologies and therefore closer fMRI fingerprints and therefore these data points should show up closer on the T-SNE visualization. In other words, we should expect some kind of continuum between the "male cluster" and "female cluster" due to the fact that a culture's effect on an individual varies from person to person (like a continuum) and there exist some individuals who are less permeable to gender-based cultural influences.

One look at the T-SNE visualization contradicts this prediction, meaning that psychological differences between men and women CANNOT purely be ascribed to cultural differences. This disproves point #1.

Some may find a T-SNE visualization unpalatable since the axes don't really tell us "in what easily understandable, concrete ways are the male and female brains different?" The brain is an incredibly complex piece of machinery of course, so these differences that may be obvious to a deep learning algorithm may be confusing and meaningless to us humans.

For a more concrete case, consider the following excerpt from the article involving the topic of human intelligence:

"Just as remarkably, the Stanford team mapped fMRI patterns of connectivity onto cognitive functions such as intelligence. They found particular patterns of connectivity within male brains that accurately predicted cognitive functions such as intelligence. However, that male model had no predictive power for cognitive functions in women.

Conversely, they found particular patterns of connectivity within female brains that accurately predicted cognitive functions such as intelligence among women. However, that female model had no predictive power for cognitive functions in men."

Here are the relevant graphs: https://imgur.com/a/hLj0OAv

What does this mean? The fact that characteristics that determine cognitive function in the male brain don't do the same for the female brain and vice versa strongly suggests that male and female brains don't "operate" the same on a fundamental level. Think different software running on the same hardware. This goes beyond the caveman like reasoning of "haha our brains look the same to the naked eye that mean we think the same."

Finally, the author wrote a paragraph that I think will resound strongly with the politically incorrect denizens of this sub:

"There has been very little coverage of this report in the mainstream media. You will find no mention of this study in The New York Times, the Wall Street Journal, or National Public Radio. I suspect that’s because most mainstream media are cautious of anything having to do with brain-based differences between women and men. Many of us are understandably wary that any claim of difference will lead to claims regarding ability. If men’s brains are different from women’s brains, doesn’t that imply that men will be better at some things and women will be better at other things? Especially when there is no overlap in the findings?"