The Male Brain

The Female Brain

This book had its beginnings during my educational years at U.C. Berkeley, Yale, Harvard, and U.C. London, so I would like to thank those teachers who most influenced my thinking during those years: Frank Beach, Mina Bissell, Harold Bloom, Marion Diamond, Walter Freeman, Florence Haseltine, Richard Lowenstein, Daniel Mazia, Fred Naftolin, Stanley Jackson, Roy Porter, Carl Salzman, Leon Shapiro, Rick Shelton, Gunter Stent, Frank Thomas, George Valliant, Clyde Willson, Fred Wilt, Richard Wollheim.

During my years on the faculty at Harvard and UCSF, my thinking has been influenced by: Cori Bargman, Samuel Barondes, Sue Carter, Regina Casper, Lee Cohen, Mary Dallman, Allison Doupe, Deborah Grady, Mel Grumbach, Leston Havens, Joel Kramer, Fernand Labrie, Sindy Mellon, Michael Merzenich, Joseph Morales, Kim Norman, Barbara Parry, Victor Reus, Eugene Roberts, Nirao Shah, Carla Shatz, Stephen Stahl, Marc Tessier-Lavigne, Rebecca Turner, Owen Wolkowitz, Chuck Yingling, and Ken Zack.

My colleagues, staff, residents, medical students, and patients in the Women's and Hormone Clinic. I would especially like to thank my faculty members at the clinic: Lyn Gracie Adams, Steve Hamilton, Dannah Hirsch, Jane Hong, Shana Levy, Faina Novosolov, and Elizabeth Springer.

And for their friendship and support throughout: Lynne Benioff, Marc Benioff, Diane Cirincione, Janet Durant, Adrienne Larkin, Sharon Melodia, Nancy Milliken, Jeanne Roberston, Sandy Robertson, Alla Spivak, and Jodi Yeary.

The work presented in this book has been based on and greatly benefited from the research and writings of: Marty Altemus, Arthur Arnold, Arthur Aron, Simon Baron-Cohen, Andreas Bartels, Frank Beach, Jill Becker, Sherri Berenbaum, Karen Berkley, Jeff Blaustein, Marc Breedlove, Lucy Brown, David Buss, Larry Cahill, Anne Campbell, Sue Carter, David Crews, Susan Davis, Karl Deisseroth, Geert De Vries, Catherine Dulac, Elisa Epel, Helen Fisher, David Geary, Jay Giedd, Jill Goldstein, Louis Gooren, Mel Grumbach, Andy Guay, Elizabeth Hampson, Bob Handa, James Herman, Melissa Hines, Gert Holstege, Sarah Hrdy, Janet Hyde, Tom Insel, Bob Jaffe, Doreen Kimura, Eleanor Maccoby, Dev Manoli, Helen Mayberg, Martha McClintock, Erin McClure, Bruce McEwen, Michael Meaney, Toni Pak, Barbara Parry, Don Pfaff, David Rubinow, Robert Sapolsky, Peter Schmidt, Nirao Shah, Barbara Sherwin, Elizabeth Spelke, Dick Swaab, Jane Taylor, Shelley Taylor, Rebecca Turner, Kristin Uvnas-Moberg, Victor Viau, Myrna Weissman, Sandra Witelson, Sam Yen, Kimberly Yonkers, Elizabeth Young, Larry Young, and the many other scientists whose work I have cited in this book.

I would also like to thank the foundations and supporters of my work: the Lynne and Marc Benioff Family, the Lawrence Ellison Medical Foundation, National Center for Excellence in Women's Health at UCSF, the Osher Foundation, the Staglin Family Music Festival for Mental Health, the
Salesforce.com
Foundation, the Stanley Foundation, and the UCSF Department of Psychiatry.

I would especially like to thank Diane Middlebrook and the Literary Salon. Diane set the stage for me to begin writing; she read many drafts of my work and was, and is, an inspiration even past her untimely death.

Amy Hertz believed in this book from day one and deserves special thanks for helping shape my thinking and writing over the years.

I am very thankful to those who worked to make this book happen: Julie Sills, Stephanie Bowen, Elizabeth Rendfleisch, Mark Birkey, Gary Stimeling, Lorraine Glennon, Diane Salvatore, my ever encouraging agent, Lisa Queen of Queen Literary, and my dedicated publicity manager at Random House, Rachel Rokicki.

I am grateful to my editor at Random House, Kris Puo-polo, who supported me with intelligence, skill, and dedication through many years of writing, rewriting, starts, and stops.

I also want to thank my son, John "Whitney," for graciously allowing me to use many of his personal stories and whose help in understanding the world of boys, teens, and young men has been invaluable. His sense of humor and determination continue to inspire me.

Most of all I thank my husband and soul mate, Sam Barondes, for everything--his insights into the world of men, his wisdom, levity, intelligence, critiques, editorial advice, scientific acumen, tolerance, empathy, and love.

Scientists think of brain areas like the ACC, TPJ, and RCZ as being "hubs" of brain activation, sending electrical signals to other areas of the brain, causing behaviors to occur or not occur
.

1. MEDIAL PREOPTIC AREA (MPOA): This is the area for sexual pursuit, found in the hypothalamus, and it is
2.5 times larger in the male. Men need it to start an erection.

2. TEMPORAL PARIETAL JUNCTION (TPJ): The solution seeker, this "cognitive empathy" brain hub rallies the brain's resources to solve distressing problems while taking into account the perspective of the other person or people involved. During interpersonal emotional exchanges, it's more active in the male brain, comes on-line more quickly, and races toward a "fix-it-fast" solution.

3. DORSAL PREMAMMILLARY NUCLEUS (DPN): The defend-your-turf area, it lies deep inside the hypothalamus and contains the circuitry for a male's instinctive one-upmanship, territorial defense, fear, and aggression. It's larger in males than in females and contains special circuits to detect territorial challenges by other males, making men more sensitive to potential turf threats.

4. AMYGDALA: The alarm system for threats, fear, and danger. Drives emotional impulses. It gets fired up to fight by testosterone, vasopressin, and cortisol and is calmed by oxytocin. This area is larger in men than in women.

5. ROSTRAL CINGULATE ZONE (RCZ): The brain's barometer for registering social approval or disapproval. This "I am accepted or not" area keeps humans from making the most fundamental social mistake: being too different from others. The RCZ is the brain center for processing social errors. It alerts us when we're not hitting the mark in our relationship or job. During puberty, it may help males reset their facial responses to hide their emotions.
6. VENTRAL TEGMENTAL AREA (VTA): It's the motivation center--an area deep in the center of the brain that manufactures dopamine, a neurotransmitter required for initiating movement, motivation, and reward. It is more active in the male brain.

7. PERIAQUEDUCTAL GRAY (PAG): The PAG is part of the brain's pain circuit, helping to control involuntary pleasure and pain. During sexual intercourse, it is the center for pain suppression, intense pleasure, and moaning. It is more active during sex in the male brain.

8. MIRROR-NEURON SYSTEM (MNS): The "I feel what you feel" emotional empathy system. Gets in sync with others' emotions by reading facial expressions and interpreting tone of voice and other nonverbal emotional cues. It is larger and more active in the female brain.

9. ANTERIOR CINGULATE CORTEX (ACC): It's the worry-wart, fear-of-punishment area and center of sexual performance anxiety. It's smaller in men than in women. It weighs options, detects conflicts, motivates decisions. Testosterone decreases worries about punishment. The ACC is also the area for self-consciousness.

10. PREFRONTAL CORTEX (PFC): The CEO of the brain, the PFC focuses on the matter at hand and makes good judgments. This "pay total attention to this now" area also works as an inhibiting system to put the brakes on impulses. It's larger in women and matures faster in females than in males by one to two years.