The Female Brain Read Online Free PDF

mentioned it to Cara. Leila, at eighteen months, picked up on my tone of voice. She climbed onto my lap and played with my earrings, hair, and glasses. She held my face in her hands, looked right into my eyes, and I felt better immediately. That little girl knew exactly what she was doing.
    At this stage Leila was in the hormone phase of what is called infantile puberty, a period that lasts only nine months for boys, but is twenty-four months long for girls. During this time, the ovaries begin producing huge amounts of estrogen—comparable to the level of an adult female—that marinate the little girl’s brain. Scientists believe these infantile estrogen surges are needed to prompt the development of the ovaries and brain for reproductive purposes. But this high quantity of estrogen also stimulates the brain circuits that are rapidly being built. It spurs the growth and development of neurons, further enhancing the female brain circuits and centers for observation, communication, gut feelings, even tending and caring. Estrogen is priming these innate female brain circuits so that this little girl can master her skills in social nuance and promote her fertility. That’s why she was able to be so emotionally adept while still in diapers.
    I NHERITING M ORE T HAN M OM’S G ENES
    Because of her ability to observe and feel emotional cues, a girl actually incorporates her mother’s nervous system into her own. Sheila came to me wanting some help dealing with her kids. With her first husband she had two daughters, Lisa and Jennifer. When Lisa was born, Sheila was still happy and content in her first marriage. She was an able and highly nurturing mother. By the time Jennifer was born, eighteen months later, circumstances had changed considerably. Her husband had become a flagrant philanderer. Sheila was being harassed by the husband of the woman he was having an affair with. And things got worse. Sheila’s unfaithful husband had a powerful and rich father, who threatened to have the children kidnapped if she tried to leave the state to be with her own family for support.
    It was in this stressful environment that Jennifer spent her infancy. Jennifer became suspicious of everyone and by age six started telling her older sister that their kind and beloved new stepfather was certainly cheating on their mother. Jennifer was sure of it and repeated her suspicions frequently. Lisa, finally went to their mom and asked if it were true. Their new stepfather was one of those men who just didn’t have it in him to cheat, and Sheila knew it. She couldn’t figure out why her younger daughter had become so anxiously fixated on the imagined infidelity of her new husband. But Jennifer’s nervous system had imprinted the unsafe perceptual reality of her earliest years, so even good people seemed unreliable and threatening. The two sisters were raised by the same mother but under different circumstances, so one daughter’s brain circuits had incorporated a nurturing, safe mom and the other’s a fearful, anxious one.
    The “nervous system environment” a girl absorbs during her first two years becomes a view of reality that will affect her for the rest of her life. Studies in mammals now show that this early stress versus calm incorporation—called epigenetic imprinting—can be passed down through several generations. Research in mammals by Michael Meaney’s group has shown that female offspring are highly affected by how calm and nurturing their mothers are. This relation has also been shown in human females and nonhuman primates. Stressed mothers naturally become less nurturing, and their baby girls incorporate stressed nervous systems that change the girls’ perception of reality. This isn’t about what’s learned cognitively—it’s about what is absorbed by the cellular microcircuitry at the neurological level. This may explain why some sisters can have amazingly different outlooks. It appears that boys may not incorporate so