Male and Female Brains Really Are Built Differently

Male (upper) and female (lower) brain connections (PNAS)


The hemispheres of women’s brains are more interconnected. Does that matter?

By Olga Khazan

“Ready your knowing smirk, because here comes a scientific gem that’s sure to enliven even the dullest of holiday parties.

By analyzing the MRIs of 949 people aged 8 to 22, scientists at the University of Pennsylvania found that male brains have more connections within each hemisphere, while female brains are more interconnected between hemispheres.

Yes, take that, Mike from IT! It, like, so explains why you just dropped the eggnog while attempting to make flirty conversation with Janet from Accounting.

Just kidding; we still have no idea why men or women do anything in particular. But the study, released today in the Proceedings of the National Academy of Sciences, is interesting because it is one of the first to discover differences in the brain’s structural connectivity in a large sample size of people from a variety of age groups.

Male (upper) and female (lower) brain connections (PNAS)

By analyzing the subjects’ MRIs using diffusion imaging, the scientists explored the brains’ fiber pathways, the bundles of axons that act as highways routing information from one part of the mind to the other. After grouping the image by sex and inspecting the differences between the two aggregate “male” and “female” pictures, the researchers found that in men, fiber pathways run back and forth within each hemisphere, while in women they tend to zig-zag between the left, or “logical,” and right, or “creative,” sides of the brain.

Because female brains seem to have a stronger connections between their logical and intuitive parts, “when women are asked to do particularly hard tasks, they might engage very different parts of the brain,” said Ragini Verma, an associate professor of radiology at the University of Pennsylvania and one of the authors of the report. “Men might over-engage just one part of the brain.”

Child (B), adolescent (C), and adult (D) brains (PNAS)

This could mean, for example, that men tend to see issues and resolve them directly, due to the strong connections between the “perception” and “action” areas of their brains, while women might be more inclined to combine logic and intuition when solving a problem.

Their less-interconnected hemispheres might prompt men, for example, to be, “going along, executing things very skillfully and maybe not taking into account that someone didn’t [do something] because they were having a bad day,” Verma explained. Meanwhile, “gut feelings, trying to join the dots together … women are known to be very strong in that.”

The differences were less evident in young children, but they became prominent in the scans of the adolescents.

Child (B), adolescent (C), and adult (D) brains (PNAS)

Scientists have long known that male and female brains are distinct, but the degree of these differences, and whether they impact behavior, is still somewhat of a mystery. The field has repeatedly unearthed seemingly solid clues that turned out to be red herrings. In August, for example, a study in the journal PLoS One challenged the long-held idea that male and female brains exhibit differences in “lateralization,” or strengths in one half of the brain or another. And past books on the “male” and “female” styles of thinking have been criticized for only including studies that reinforce well-known gender stereotypes.

At the same time, there’s plenty of evidence that male brains are from Mars and female brains are, well, from a different neighborhood on Mars. Researchers already know, for example, that men’s brains are slightly bigger than women’s (because men’s bodies also tend to be bigger). Male and female rats navigate space differently. Women taking birth control pills, which alter estrogen and progesterone levels, have been shown to remember emotionally charged events more like men do in small studies. Migraines not only strike women more frequently, but they impact different parts of their brains, too.

A study published last month in the journal Nature Communications found that genes are expressed differently in men and women throughout the brain. One reason autism rates are higher among males, the researchers suggest, could be because a form of the gene NRXN3 is produced at higher levels in male brains.

And past research has shown that, across cultures, women’s brains are more functionally interconnected when at rest than men’s are, on average. This and similar findings have been used to support the idea that women are “better at multitasking.” And indeed, a study released late last month by researchers at the University of Glasgow in Scotland found that women do have an edge when it comes to switching between tasks rapidly, ostensibly because, back in the cave, we had to keep an eye on the kids while we … did whatever else it is that cave housewives did.

But examining the brain differences between the sexes also has an ugly past, since such findings have historically been used to paint women as less rational or intelligent.

The 19th-century French anthropologist Paul Broca, who lends his name to the area of the brain responsible for speech, once said, “We are therefore permitted to suppose that the relatively small size of the female brain depends in part upon her physical inferiority and in part upon her intellectual inferiority.”

At the same time, though, modern medicine can’t afford to ignore these variations. Just as with any disease, understanding sex differences in brains might help neuroscientists better diagnose and treat disorders.

“We see these differences everywhere, and we started to realize, damn, we simply assume they aren’t there,” Larry Cahill, a neuroscientist at the University of California at Irvine, told the Orange County Register. “And these sex differences have implications for how the brain works and how to fix brains.”

Even pain medications don’t take male and female pain perception differences into account, Cahill points out. Countless medical fields have long been treating women by pretending “they are simply men with pesky sex hormones.”

The most uncomfortable aspect of such findings is that they can be—and often are—twisted to prop up stereotypes and prejudices. Studies like the PNAS one might offer fodder for those who wish to explain away female underrepresentation in fields like engineering with factoids about brain “wiring.” (Something former Harvard president Larry Summers essentially once suggested.)

But of course, that kind of thinking leaves out culture, which plays a big role not only in shaping how we think—both inside and outside of MRI machines—but also in determining what we do with our brains, however they’re structured. Verma emphasized that there’s a great deal of variation between individuals. Different fiber-pathway configurations don’t necessarily predestine someone to behave or think a certain way.

“There is a lot to be said about the structural wiring of the brain,” Verma said, “but it’s what you use the wiring for that changes the person that you are.”

Or as Anke Ehrhardt, a psychiatry professor at Columbia University Medical Center cautioned during a recent panel on neuroscience and gender, “Acknowledging brain effects by gender does not mean these are immutable, permanent determinants of behavior, but rather they may play a part within a multitude of factors and certainly can be shaped by social and environmental influences.”

Spoken like someone who has her intuition wired firmly to her logic.”



36 responses to this post.

  1. Now let’s look at male and female brains that have been abused as children

    PTSD impacts gender in different ways

    Men have this strong connection inside our left cognitive hemisphere, that seems to bode badly for dissociation and ptsd symptoms

    Seems to be harmful to attaching to others.

    While women have much more interconnection between hemispheres. how does this impact ptsd differently.

    Seems to me women attach to each other easier and more often than us men with childhood abuse.

    I do not have any motherly instinct or deep emotional attachments to damn near anything

    For me I guess I crave the feelings I see women engage in.

    The importance of closeness, hugs and this emotional connection they share with other females.

    Place me in the middle of males and I will isolate and build boundaries

    It’s the same placing me in the middle of a group of women

    I find people untrustworthy and dangerous

    Our male brains isolate much easier it seems to me

    Women have so much more connection, community, feeling like being a part of society and others, than I ever had.

    My cognitive right hemisphere brings suffering through past trauma

  2. I think male and female brains were designed to compliment each other and we need to celebrate the differences. We need each other to be the best we can be.
    I can also agree that abuse affects the genders differently. I don’t understand the differences and I’m still a bit frustrated about that. (relating to the men in my life.)
    I agree that men don’t form attachments as easily. They may not believe it but they do have the ability to learn. The key element is pulling down the walls. I’m going to sound a little bitter here but I know all about male walls and the stubborn refusal to acknowledge them never mind pull them down.
    On the other hand I’ve seen healthy happy men with strong attachments.
    I think pulling the walls down has to do with the narrative running in our head. There is a saying “If you think you can. If you think you can’t. You are right”
    Walls aren’t a male problem, they are a people problem. I do think men have a greater struggle though and it’s tied to the ego (this is not a bad thing, it just is.) Women need to feel loved. Men need to feel affirmed. Taking walls down is scary. What if… ?
    Some people are untrustworthy and dangerous but not all people are. Actually, a very small percentage are. I will agree that in certain settings the percentage is significantly higher. Your experience in the sports world has added to your paranoia on that score I’m sure.
    You aren’t alone in your thinking, I’ve made similar blanket statements and avoid certain groups of people based on past experience with a few.
    I find I have to ask myself the question – what is really true? and then I have to repeat over and over, most people are trustworthy. Few people are dangerous. Repetition of the truth can over rule the lies in our heads.
    The place we can get into trouble though is related to abuse and triggers. Great offense happens when one is triggered, walls go up, we shut down, pull back and now we are both triggered. I’ve experienced this in female friendships recently and fractures happen. I think part of the responsibility for this is inequality in our pursuit of wellness. We are at different places on our journey. That’s a whole discussion for another time but it’s something important to be aware of.
    Hugs are very important. There are studies out, related to loneliness in the elderly (I guess that’s us 🙂 ) and they find that a number of hugs are required everyday for optimal emotional health and longevity.
    For those of us living alone, or without a healthy relationship we are on a starvation diet. Part of that is caused by our isolationist tendencies. Even knowing the benefits of allowing someone in our life, it’s scary.
    They say love heals and I think it’s true. Sometimes a hug with no words can say far more than any conversation possibly could.
    I think it’s a healthy sign that you recognize and want.

  3. Well said
    I was surprised reading male and females use different parts of the brain to solve the same problem

    We need to understand that I believe


    Touch. The only touch I had as a kid was being beaten so people hugging me, especially strangers does not bring me warmth

    There are studies out, related to loneliness in the elderly (I guess that’s us 🙂 ) and they find that a number of hugs are required everyday for optimal emotional health and longevity.

    I know I am different than other people
    I do not yearn for hugs and do not get the warm and fuzzies other people do
    I watch other people enjoy this sharing with joy

    They say love heals and I think it’s true

    What is love

    I think you need trust to love
    My trust is shallow

    I did not attach to anyone is childhood

    So really trusting someone deeply is not something that has worked out for me

    A hug is not something I desire

    That makes me so different I know

  4. I get where you are coming from. Our childhoods were pretty similar. Mine wasn’t as harsh, if you consider violation less harsh than beatings. I guess I do look at it that way, less harsh. Hugs don’t come easy to me. I shy away from physical contact with people as a general rule. And yet I have experienced hugs that I wish I could experience again.
    As far as desiring goes. We can’t gauge our need by our level of want.
    The need for touch is primal, built into our DNA and has nothing to do with how we feel about it . On the same level we need food, water, air, and rest, we need human touch, we need love.
    Babies have proved this. Newborns have no conscious thought about need. Studies have found that newborns held and touched thrive in a way that the minimal touch group does not. That’s why, now they encourage immediate baby skin on skin connection with both mom and dad.
    What is love?
    1st Corinthians chapter 13 verses 4 – 8 New International Version describes it perfectly and that is why it’s called the Love Chapter.
    4 Love is patient, love is kind. It does not envy, it does not boast, it is not proud. 5 It does not dishonor others, it is not self-seeking, it is not easily angered, it keeps no record of wrongs. 6 Love does not delight in evil but rejoices with the truth. 7 It always protects, always trusts, always hopes, always perseveres. 8 Love never fails…
    Love is not an emotion, although it can certainly cause us to be emotional. Love is a choice. There is no trust needed in order to love. Trust is involved if you are going to commit to a locked in or intimate partnership, but not if it only involves the way you treat someone.
    Love on a basic level only requires us to care about someone else. That’s why love is a choice. We don’t have to trust to show love.
    There is another side to the touch issue though that is less easily defined. When we have been on a starvation diet of closeness and touch, it is not easy to feel comfortable when people get inside our personal circle. That’s why I visit the hairdresser about once a year, maybe, and a doctor about every 10.
    Another thought (since this narrative is all running together) Touch adds a new dimension to life and relationship. For a long time I had been avoiding even hand shakes. The trouble with that was the awkwardness that followed. I decided I needed to change that. Shake and move on. It made a huge difference. Not that I am in the position to shake very often but still, it has changed my view on some things.
    So here is a question I don’t know the answer to. Does you daughter know a father’s touch? Your grandchild? Are they on the same starvation diet you were on?
    You can do anything you set your mind to.
    If you need to change some things, talk about it so it’s not weird.
    There is a generational cycle to abuse and dysfunction. At some point someone has to stand up and say it stops with me. This has happened in my family. It’s not perfect but it is a huge improvement over what we came from.
    Love is a choice, and everyone needs a hug whether they think they do or not. Give some away and see what happens. Start with your family, you trust them.

  5. I hug my daughter more than she wants

    Her mother took her and her brother out of state without Informing me

    For most of their childhood they lived out of state

    I do not think I have experienced live outside my two kids and grandchildren

  6. Yeah I know touch is important

    What do you do if the touch has a negative impact

    Or it has a cold chill to it

    I do not feel what I watch others do and then describe how important it is to them

    What is that feeling?

    How do people trust or love a mate in an intimate relationship?

    What is that connection?

    What does that feel like

  7. Thank you for taking the time to share your thoughts

  8. At least you are experiencing love there. That is a very good sign.
    For me too, my deepest connections are to my kids and grandkids. I would do life over again the same way just to have them.

  9. I wish I had answers for both of us, to see our lives be different and healthy. Our brokenness runs so deep. Incremental changes don’t seem like enough but yet they do make a difference. Maybe one day it will all add up to healthier.
    If we live long enough lol

  10. There is a reason we relate to each other

    Similar childhood abuse

    I try to be in the present moment, I interact with people in a congenial way and can hold a conversation on multiple topics
    But that’s as deep as it goes

    I am ok with that

    I do not yearn for things others seem to need

    For me, I would never do this life over

  11. Not even to have your kids?

  12. I agree with that

    We have to fight for our incremental moments

    I am almost ashamed to know how messed up my life is

  13. I never wanted kids
    Knew I did not have the skills to parent

    My ex wife knew that but stopped taking the pill behind my back

    I was not a good father

    I could not survive my childhood the second time around

    I could not live through that again

  14. My judgment

    I have carried shame since early childhood

    My dad never said a kind word to me

    I could not do my childhood over

    I rather be dead

  15. Were you afraid you would be your father? Were you your father? Partially?

  16. No way

    I am opposite of my father

    Ge was narcissist

    I am long way from that

  17. Shame is different than guilt. A very important distinction.

  18. I told my daughter to never bury me or spread my ashes anywhere near my father

  19. Shame is at core

    I was shamed as a kid

  20. Do you have a good relationship with your kids now? Do they feel loved by you?

  21. My daughter yes
    My son is a different story

    My grandkids I live with

    I am in their midst

  22. The abused always feel shame. it’s because of what was done to them not because of who they are. That is very important to remember.

  23. Does your son have kids?

  24. Life is strange

    As kids, we never knew we would be struggling with these issues late in life

  25. That’s true. it’s probably a blessing. We had enough to handle doing life with a young family, trying to make a living and all that goes along with all of that. To deal with our childhood back then would have been a killer.
    Besides with age we look at life through different, softer, lenses.

  26. Where was your mother in all of this?

  27. Yea

    I do not know what to say about my kids

    But redoing my childhood is not an option

    Besides with age we look at life through different, softer, lenses.

    My lenses are not softer I do not think

  28. So why do you have to redo your childhood?

  29. Enabler

    She shopped and then cooked the Lima beans each Thursday

    He beat me for puking lima beans she fixed every week

  30. To live life again

  31. explain. What does that mean?

  32. I would never take a chance I would be born I to the same or worse childhood


  33. I’m just trying to understand. You’ve made a similar comment more than once and I’m not clear on what you are thinking. Are you afraid you would behave like your father? What are you afraid of? You don’t have to answer if you don’t have a clear picture of what that looks like. I’m guessing it would be tied to how you think you would behave or maybe who you think you are. Unworthy, incapable.
    I’m confused 🙂

  34. How could you relive your childhood through your kids?

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: