Wednesday, March 24, 2010

Q&A With Dr. Louann Brizendine, Author of 'The Male Brain'

I'm not sure I buy into this idea that the male brain is simply a female brain "marinated in testosterone" - sounds like a not so subtle form of sexism. I have no doubt that there are neurological differences in the brains, but I tend to believe that some of the greatest differences between men and women are a result of socialization and attachment styles.

By age one, female children make more eye contact than male children. Is this inborn? Or is this a result of female children being raised from day one with more interpersonal emphasis, while male children tend to be allowed to self-soothe?

I'm hesitant to place too much value in these discussion since we know that various within gender expressions is greater than variation between sexes.

Dr. Louann Brizendine Discusses Differences in Male, Female Brains

March 24, 2010

This morning, Dr. Louann Brizendine appeared on "Good Morning America" to discuss her research into male hormones and to talk about her new book, "The Male Brain."

Dr. Louann Brizendine, author of the book
Dr. Louann Brizendine, author of the book, "The Male Brain," says research suggests that men with certain genes may be more prone to infidelity.(Getty Images)

Brizendine is the author of the best-selling book, The Female Brain.

In her new book, she uses the latest scientific research to unlock the secrets of the male brain, revealing an often shocking gulf between the sexes.

Here is an interview with Brizendine:

Q: You describe the male brain as a female brain "marinated in testosterone" during gestation. Can you elaborate?

A: We all start out from conception until 8 weeks of fetal life with female-type brain circuits and then the tiny testicles begin to squirt out huge amounts of testosterone that marinate the brain turning it into a male brain. (The combination of male genes on the Y chromosome and testosterone is what makes a male a male.) However, grown-up men still have many of the original brain circuits that started out as female. Males learn and are taught to suppress their emotional expression. So when they grow up they are often too embarrassed to express very much emotion and it's easy for them to hide their feelings because their brain circuits have learned how to hold a stoic poker face.

Q: What other effects does this high level of testosterone have on men?

A: In his teen years, when a boy's testosterone skyrockets, he starts to see the world as an angrier place. He literally reads "neutral" faces as angry. Seeing the angry face increases his own anger and can trigger his aggression circuits. It's a knee jerk reaction that often surprises him. Testosterone can also help to fuel something called autocatalytic anger. This is when a man's anger feeds on itself and grows. A word to the wise: Do not add fuel to this fire. Whatever you have to say can wait until the testosterone surge subsides.

Q: What is the biggest difference between the female and the male brain, what are the biggest similarities?

A: The male and female brain are mostly alike. We are the same species after all. But the differences that do exist are big. The testosterone marination during fetal life makes the area-for-sexual-pursuit in the male hypothalamus grow to be 2.5 times larger than the female and then in the teen boy brain he has 200 to 250% more testosterone than teen girls, which will last his entire life.

Q: Why are there so many problems in communicating between the sexes?

A: Males and females have many different needs and objectives, especially when it comes to mating, sex and child rearing. We tend to approach topics and solve problems using different parts of our brains and that's why we sometimes can't see eye to eye. The key to better communication is understanding how the other person's brain works and how he or she views the world. When a man and woman have that understanding of each other, it is possible to bridge the communication gap.

On the Mating Brain and the Hormone of Monogamy: He either operates as a stay-at-home dad or as a playboy-depending on his vasopressin receptor gene. There is no sure-fire answer for what makes men monogamous (or not), but research on male voles has provided clues. Scientists have found that the prairie vole is monogamous and takes equal responsibility for his offspring. But his cousin, the montane vole, is promiscuous and specializes in one-night stands. The difference between these cousins occurs in the brain. When prairie voles mate, the repeated release of vasopressin during sex causes a change in the male's brain, helping him memorize his partner's smell, touch, and appearance-and leading him to reject all others. The montane male vole's brain also releases vasopressin during sex, but his brain receptors respond differently and do not produce a preference for one female. In humans, the men with a longer vassopressin gene get married and stay married longer according to a study in Sweden--and the men with the shorter gene are more likely to remain promiscuous bachelors. The genes resulting in mono-gamous brain receptors for vasopressin get passed down from father to son. So if you want the best chance of choosing a monogamous male, take a good look at the behavior of his biological father.

On Emotional Intimacy: If you've ever said, "He obviously doesn't care how I feel," this lesson is for you. When faced with an emotionally charged issue, a man's brain switches into analytic mode. His focus is on solving the problem-there's no time for empathy and sympathy for his suffering female partner. After a fight, men often appear to women to be expressionless and shutting down. In fact, the opposite may be true: he's just using a different brain system to try to improve the situation.

Q: Which are the most surprising insights into men you gained?

A: The daddy brain is formed from smelling the pheromones of his pregnant partner. And, that little boys in the classroom learn better when they're allowed to move around, squirm and fidget.

Visit Dr. Louann Brizendine on her Web site at, or click HERE.
Here is an excerpt from the The Male Brain:

Introduction: What Makes A Man

You could say that my whole career prepared me to write my first book, The Female Brain. As a medical student I had been shocked to discover that major scientific research frequently excluded women because it was believed that their menstrual cycles would ruin the data. That meant that large areas of science and medicine used the male as the "default" model for understanding human biology and behavior, and only in the past few years has that really begun to change. My early discovery of this basic inequity led me to base my career at Harvard and the University of California–San Francisco (UCSF) around understanding how hormones affect the female and male brains differently and to found the Women's Mood and Hormone clinic. Ultimately that work led me to write The Female Brain, which addressed the brain structures and hormonal biology that create a uniquely female reality at every stage of life.

The distinct brain structures and hormonal biology in the male similarly produce a uniquely male reality at every stage of life. Yet as I considered writing The Male Brain, nearly everyone I consulted made the same joke: "That will be a short book! Maybe more of a pamphlet." I realized that the idea that the male is the "default model" human being still deeply pervades our culture. The male is considered simple; the female complex.

Yet my clinical work and the research in many fields, from neuroscience to evolutionary biology, show a different picture. Simplifying the entire male brain to just the "brain below the belt" is a good set up for jokes, but it hardly represents the totality of a man's brain. There are also the "seek and pursue" baby boy brain, the "must move or I will die" toddler brain; the sleep-deprived, deeply bored, danger-seeking teen brain; the passionately bonded mating brain; the besotted daddy brain, the obsessed-with-hierarchy aggressive brain and the fix-it-fast emotional brain. In reality, the male brain is a lean mean problem-solving machine.

The vast new body of brain science together with the work I've done with my male patients has convinced me that through every phase of life, the unique brain structures and hormones of boys and men create a "male reality" that is fundamentally different from the female one, and all too frequently oversimplified and misunderstood.

Male and female brains are different from the moment of conception. It seems obvious to say that all the cells in a man's brain and body are male. Yet this means that there are deep differences, at the level of every cell, between the male and female brain. A male cell has a Y chromosome and the female does not. That small, but significant difference begins to play out early in the brain as genes set the stage for later amplification by hormones. By eight weeks after conception the tiny male testicles begin to produce enough testosterone to marinate the brain and fundamentally alter its structure.

Over the course of a man's life, the brain will be formed and re-formed according to a blueprint drafted both by genes and male sex hormones. And this male brain biology produces his distinctly male behaviors.

The Male Brain draws on my twenty-five years of clinical experience as a neuropsychiatrist. It presents research findings from the spectacular advances over the past decade in our understanding of developmental neuroendocrinology, genetics, and molecular neuroscience. It offers samplings from neuropsychology, cognitive neuroscience, child development, brain imaging, and psychoneuroendocrinology. It explores primatology, animal studies, and observation of infants, children, and teens, seeking insights into how particular behaviors are programmed into the male brain by a combination of nature and nurture.

During this time, advances in genetics, electrophysiology and noninvasive brain-mapping technology have ignited a revolution in neuroscientific research and theory. Powerful new scientific tools, such as genetic and chemical tracers, positron-emission tomography (PET) and functional magnetic resonance imaging (fMRI), now allow us to see inside the working human brain while it's solving problems, producing words, retrieving memories, making decisions, noticing facial expression, falling in love, listening to babies cry, and feeling anger, sadness or fear. As a result, scientists have recorded a catalog of genetic, structural, chemical, hormonal and processing brain differences between women and men.

In the female brain, the hormones estrogen, progesterone and oxytocin predispose brain circuits toward female-typical behaviors. In the male brain, it's testosterone, vasopressin and a hormone called MIS (mullerian inhibiting substance) that have some of the earliest and most enduring effects. The behavioral influences of male and female hormones on the brain are major. We have learned that men use different brain circuits to process spatial information and solve emotional problems. Their brain circuits and nervous system are wired to their muscles differently—especially in the face. The female and male brains hear, see, intuit, and gauge what others are feeling in their own special ways. Overall, the brain circuits in male and female brains are very similar, but men and women can arrive at and accomplish the same goals and tasks using different circuits.

We also know that men have two and a half times the brain space devoted to sexual drive in their hypothalamus. Sexual thoughts flicker in the background of a man's visual cortex all day and night, making him always at the ready for seizing sexual opportunity. Women don't always realize that the penis has a mind of its own—for neurological reasons. And mating is as important to men as it is to women. Once a man's love and lust circuits are in sync, he falls just as head over heels in love as a woman – perhaps even more so. When a baby is on the way, the male brain changes in specific and dramatic ways to form the daddy brain.

Men also have larger brain centers for muscular action and aggression. His brain circuits for mate protection and territorial defense are hormonally primed for action starting at puberty. Pecking order and hierarchy matter more deeply to men than most women realize. Men also have larger processors in the core of the most primitive area of the brain, which registers fear and triggers protective aggression – the amygdala. This is why some men will fight to the death defending their loved ones. What's more, when faced with a loved one's emotional distress, his brain area for problem solving and fixing the situation will immediately spark.

Read more.

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