Louann Brizendine: 'The Male Brain'

March 24, 2010 — -- The author of "The Female Brain" tackles a new subject: men.

Dr. Louann Brizendine walks her readers through the science behind the male brain in hopes that she helps her audience understand the male brain "as the fine-tuned and complex instrument that it actually is," as she writes in her book.

Check out an excerpt of the book below, then head to the "GMA" Library for other great reads.If you'd like to read an interview with Brizendine, click HERE.

And click here to read Dr. Brizendine's take on the differences between men and women on The Huffington Post's Books section.

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.