The Female Brain by Louann Md Brizendine

fine-tunes emotional responsivity. These enhanced brain circuits will stabilize into their adult shape by late puberty and into early adulthood. At the same time, we now know that the estrogen and progesterone surges start making the adolescent female brain, especially the hippocampus, experience weekly changes in sensitivity to stress that will continue until she passes through menopause.
    Researchers at the Pittsburg Psychobiologic Studies Center studied normal seven-to sixteen-year-olds as they progressed through puberty, testing their stress responsivity and their daily levels of cortisol. The girls showed more intense responses, while boys’ stress responsiveness dropped. Females’ bodies and brains react to stress differently than do males’ once they have entered puberty. Fluctuating estrogen and progesterone in the brain is responsible for this opposite stress responsivity in the hippocampus of females. Males and females become reactive to different kinds of stress. Girls begin to react more to relationship stresses and boys to challenges to their authority. Relationship conflict is what drives a teen girl’s stress system wild. She needs to be liked and socially connected; a teen boy needs to be respected and higher in the male pecking order.
    The girl’s brain circuits are arranged and fueled by estrogen to respond to stress with nurturant activities and the creation of protective social networks. She hates relationship conflict. Her brain’s stress response is massively triggered by social rejection. The ebb and flow of estrogen during the menstrual cycle changes this sensitivity to psychological and social stress on a weekly basis. The first two weeks of the cycle, when estrogen is high, a girl is more likely to be socially interested and relaxed with others. In the last two weeks of the cycle, when progesterone is high and estrogen is lower, she is more likely to react with increased irritability and will want to be left alone. Estrogen and progesterone reset the brain’s stress response each month. A girl’s self-confidence may be high one week but on thin ice the next.
    During the juvenile pause of childhood, when estrogen levels are stable and low, a girl’s stress system is calmer and more constant. Once estrogen and progesterone levels climb at puberty, her responsivity to both stress and pain start to rise, all marked by new reactions in the brain to the stress hormone cortisol. She’s easily stressed, high-strung, and she starts looking for ways to chill out.
    S O H OW D OES S HE C ALM D OWN?
    I was teaching a class of fifteen-year-olds about brain differences between males and females, and I asked the boys and girls to come up with some questions that they’d always wanted to ask each other. The boys asked, “Why do girls go to the bathroom together?” They assumed that the answer would involve something sexual, but the girls replied: “It’s the only private place at school we can go to talk !” Needless to say, the boys couldn’t ever imagine saying to another guy: “Hey, want to go to the bathroom together?”
    That scene captures a pivotal brain difference between males and females. As we saw in Chapter 1, the circuits for social and verbal connection are more naturally hardwired in the typical female brain than in the typical male. It is during the teen years that the flood of estrogen in girls’ brains will activate oxytocin and sex-specific female brain circuits, especially those for talking, flirting, and socializing. Those high school girls hanging out in the bathroom are cementing their most important relationships—with other girls.
    Many women find biological comfort in one another’s company, and language is the glue that connects one female to another. No surprise, then, that some verbal areas of the brain are larger in women than in men and that women, on average, talk and listen a lot more than men. The numbers vary, but on average girls speak two to three times more