David Goggins
Former Navy Seal
Career Development
Bryan Cranston
Critical Thinking
Liv Boeree
International Poker Champion
Emotional Intelligence
Amaryllis Fox
Former CIA Clandestine Operative
Chris Hadfield
Retired Canadian Astronaut & Author
from the world's big
Start Learning

How should we study sex differences in a polarized age?

A new study on brain differences between sexes sparks a persistent question.

Photo: Ink Drop / Shutterstock
  • A new study found brain volume differences between men and women.
  • The research focuses on regional grey matter volume, a contentious measurement in neuroscience.
  • Without environmental conditions being considered, how trustworthy is our emphasis on biology?

In his book, "Chemically Imbalanced," University of Virginia research professor, Joseph E. Davis, questions the 20th century paradigm shift that created the belief that the brain is the last scientific frontier in understanding ourselves and the world. Neuroscience is valuable—that isn't in dispute. An expectancy that this discipline alone holds the keys to enlightenment is what's under debate.

Davis warns of the dangers of using biological explanations for social and personal dilemmas—namely, suffering. The entire field of psychiatry has fallen (or rather, been pushed) under the spell of brain chemistry, as I've repeatedly written about. Davis writes,

"Many of the claims about the relation of mind and mental states to brain are not really scientific at all and cannot themselves be tested in any empirical way. They rest no so much on a theory as on changed assumptions about human being."

This doesn't mean we should abandon the relationship of our brains to our bodies. We just can't confuse correlation with causation. In some ways, we've been sheltering in place for two centuries, thanks to indoor climate control and electricity. This "control of nature" has caused researchers to overlook the importance of the environment on mental health.

What about actual genetic differences in brain composition, however? Are they dependent on environment? This brings us to one of the more contentious debates in biology: genetic differences between men and women. A new study, published in Proceedings of the National Academy of Sciences, is forcing us to again confront that question.

The basis of the study is sound. Armin Raznahan, Chief of the Section on Developmental Neurogenomics at the National Institute of Mental Health, has been studying sex differences since he was a PhD student. He knows the field is filled with landmines. His first study was cited in an argument for same-sex schooling, which served as a wake-up call about the dangers of publishing on the subject.

Men vs. women: Why we’re imagining equality all wrong | Heather Heying | Big Think

This new research not only found sex differences in terms of regional grey matter volume (GMV), but also tied those differences to sex chromosomes. Specifically, after discovering neuroanatomical sex differences, the team found "that sex differences in regional GMV are aligned with functional systems for face processing."

This sparked the question of the validity of using grey matter to measure social and physical functioning, as this deep dive in Wired details. Raznahan's research found larger volumes of grey matter in men than women, though previous research has found women are better than men at facial recognition.

Grey matter is often used as evidence of stronger neurological connections. The default example is the famous London taxi driver study, which found that drivers, who have to memorize the entirety of the city to pass a rigorous test, have larger GMV in the brain's posterior hippocampi (spatial memory and navigation) than non-taxi drivers. This line of argument has also been used by meditation researchers, who have extrapolated from GMV volume to argue that meditation helps increase memory and empathy while decreasing stress.

Back to correlation and causation. Taxi drivers must study street maps for years; mediation is a specific discipline that has measurable effects on the nervous system (beyond grey matter). In both cases, the subjects have changed their relationship to their environment, thus hinting at correlation. If anything, you can argue environmental changes cause changes in GMV.

Raznahan's study is looking at genetic differences, yet environment still plays a role. The data was pulled from the U.S. and UK, predominantly white, wealthy countries. Comparing that data to other sets in African or Asian countries, for example, could result in a Bell Curve-type controversy—gender studies are already controversial enough. How then do you study biology when everything is polarized?

people at International Women's Day rally

Dozens of women and men attend a rally and march in Washington Square Park for International Women's Day on March 8, 2018 in New York City.

Photo by Spencer Platt/Getty Images

One political party in America grows angry any time a connection between income disparity and ethnicity is made. We seem unable to move beyond this political wedge, especially since it fires up the base, yet it holds the key to freeing scientists to take a holistic approach. You can't only look at changes in brain function when contemplating social differences. But you can investigate such differences if you're trying to understand brain disorders—the focus of Raznahan's work.

The gender question might always be with us. In 2014, Fallon Fox, a transgender MMA fighter, broke Tamikka Brents's skull during a match. Brents later said she had "never felt the strength that I felt in a fight as I did that night." There are real biological differences between men and women. Arguing against that is antithetical to good science.

Neuroscience will remain a sticky topic for some time, however. The methods for measuring blood flow and brain volume are, as Davis suggests above, more art than science. Until better measuring sticks are developed for understanding brain functionality, the field will be more speculative than declarative. That's okay: scientists need to fail in order to grow. In a time when even minor failures result in ostracism, however, that's a tough line to walk.

Environment always matters. Humans are the products of the spaces they inhabit. Genetic disorders aside, our chemistry is linked to our environment. When neuroscience is able to utilize brain scans in conjunction with sociology, real progress will be possible. Until then, controversies will abound, even where they should be none.


Stay in touch with Derek on Twitter, Facebook and Substack. His next book is "Hero's Dose: The Case For Psychedelics in Ritual and Therapy."

LIVE EVENT | Radical innovation: Unlocking the future of human invention

Innovation in manufacturing has crawled since the 1950s. That's about to speed up.

Big Think LIVE

Add event to calendar

AppleGoogleOffice 365OutlookOutlook.comYahoo

Keep reading Show less

Bubonic plague case reported in China

Health officials in China reported that a man was infected with bubonic plague, the infectious disease that caused the Black Death.

Vials Of Bacteria That May Cause Plague Missing From TX University

(Photo by Centers for Disease Control and Prevention/Getty Images)
  • The case was reported in the city of Bayannur, which has issued a level-three plague prevention warning.
  • Modern antibiotics can effectively treat bubonic plague, which spreads mainly by fleas.
  • Chinese health officials are also monitoring a newly discovered type of swine flu that has the potential to develop into a pandemic virus.
Keep reading Show less

Navy SEALs: How to build a warrior mindset

SEAL training is the ultimate test of both mental and physical strength.

  • The fact that U.S. Navy SEALs endure very rigorous training before entering the field is common knowledge, but just what happens at those facilities is less often discussed. In this video, former SEALs Brent Gleeson, David Goggins, and Eric Greitens (as well as authors Jesse Itzler and Jamie Wheal) talk about how the 18-month program is designed to build elite, disciplined operatives with immense mental toughness and resilience.
  • Wheal dives into the cutting-edge technology and science that the navy uses to prepare these individuals. Itzler shares his experience meeting and briefly living with Goggins (who was also an Army Ranger) and the things he learned about pushing past perceived limits.
  • Goggins dives into why you should leave your comfort zone, introduces the 40 percent rule, and explains why the biggest battle we all face is the one in our own minds. "Usually whatever's in front of you isn't as big as you make it out to be," says the SEAL turned motivational speaker. "We start to make these very small things enormous because we allow our minds to take control and go away from us. We have to regain control of our mind."
Keep reading Show less

New guidelines redefine 'obesity' to curb fat shaming

Is focusing solely on body mass index the best way for doctor to frame obesity?

Photo by Jeff J Mitchell/Getty Images
Surprising Science
  • New guidelines published in the Canadian Medical Association Journal argue that obesity should be defined as a condition that involves high body mass index along with a corresponding physical or mental health condition.
  • The guidelines note that classifying obesity by body mass index alone may lead to fat shaming or non-optimal treatments.
  • The guidelines offer five steps for reframing the way doctors treat obesity.
Keep reading Show less

How COVID-19 will change the way we design our homes

Pandemic-inspired housing innovation will collide with techno-acceleration.

Scroll down to load more…