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"The Female Brain" by Allen Weiss, MD, MBA, President & CEO

The Female Brain

February 1, 2014 - Two months ago in these pages, I explored the male brain. But since Valentine’s Day in February honors our “better” half, now it’s time to explore the complex and attractive female brain.

Dr. Louann Brizendine, a neuropsychiatrist at the University of California, San Francisco, published in 2006 an inclusive and entertaining review of the female brain. She started by asking,“What makes us women?”

Let’s be clear about one thing: Women are not just “small men,” even though women’s brains are on average 9% smaller than men’s. Make no mistake, females and males have the same average level of intelligence. Under the influence of estrogen, behaviors between the sexes change—which is a good thing, of course, and has had a major role in the biological preservation of our species.

Until girls and boys hit their teen years, the difference in their math and science ability is non-existent. Estrogen for girls and testosterone for boys then floods their brains. Females focus on emotions, communication, and other attributes which have been cultivated over the millennia to preserve our species. (Simultaneously, males grow less communicative and more competitive and exploratory; that was a positive adaptation for survival in the hunter-gatherer society from which we evolved.)

The complex answer to “What makes us women?” starts as early as eight weeks after conception and in the teen years becomes engaging or annoying (depending on your point of view). Biological maturation during the early reproductive years is closely followed by the nurturing phase, sometimes called the “mommy brain.” Feelings and maturity come next, encouraging the mature woman to be a healthy anchor for our society as these individuals have a comprehensive overview of our entire life cycle.

Early on a baby’s brain starts to differentiate. Baby girls’ brain circuits for communication, gut feelings, emotional memory, and anger suppression grow unabated. In contrast, baby boys’ brains—bathed in testosterone—develop the circuits for rough and tumble muscle movements, sexual pursuit, and exploratory behavior while simultaneously depressing the attributes which makes women more communicative and collaborative.

This early differentiation continues with infant girls from 6-18 months still having high levels of estrogen which in general facilitate earlier verbal development. Later in life an average women uses about 20,000 words per day; a man uses only about 7,000.

At about two years of age estrogen levels drop until puberty. Baby girls are born interested in emotional expression. During this time from two until early teens, little girls are in general more empathetic and better at reading other people’s emotions and facial expressions. Emotional intelligence, an important skill for success, is developing during this phase of childhood. Although both sexes are concerned about helping others, girls in general are more demonstrative and sensitive. They also receive more positive feedback when demonstrating nurturing behavior. Think of playing with dolls—dressing, feeding, nurturing, housing—as a way of developing interpersonal support skills.

The teenage years—get ready for drama and volatile changes—are a response to the cyclical hormonal changes which start the average of 30 years of reproductive life. During puberty, a girl’s entire biological reason for being is to become sexually desirable. She obsesses over appearance, judges herself against peers, media images, and other attractive females. If mirrors could be worn out, they would be as hours are spent in the bathroom grooming, primping, obsessing, and otherwise being concerned with appearances.

As an aside most women spend 25 of these 30 reproductive years trying not to get pregnant. Obviously, this includes unmarried teenagers. In Collier County our teenage pregnancy rate is higher than we would like and more than a few groups are working on this multigenerational and societal problem.

The teen years also bring the development of cliques and clubs. Females respond to stress and conflict by forming teams. Protecting the family or tribe is a team sport, so communication and collaboration among females has adaptive success. Females are more likely to avoid confrontation and disagreement and look instead for social contact. Think of teenage girls texting, talking on the phone, joining clubs and sororities as a way of thriving through a team. Boys, on the other hand, will have an adrenaline rush in response to conflict and switch into a “fight or flight” mode.

For females, fighting was not as evolutionally desirable as females are about 10% smaller physically than males and therefore more vulnerable. Being collaborative with likeminded females was a more successful strategy.

The young adult reproductive years of women are characterized by the dance of romance. Over the millennia our brains have been programmed to steer us towards partners who can boost our chances for successful reproduction.

In the short term, men are chasers and women are choosers. During the 99% of the million years humans evolved, the more successful reproducers were selected for survival. This evolution programmed deep into our brains an architecture of love. The shapes, faces, smells, and ages of the mates we choose are influenced by these ancient patterns.

In choosing mates, “symmetry” always wins out as this characteristic is a proxy for good health, which is a prerequisite for reproductive success. Symmetrical men have the shortest courtship and invest the least amount of time and money on their dates.

One particularly likable characteristic of the female brain is the “mommy brain.” Long after pregnancy is long over, a mother is still living and breathing for two. In fact, in close families even when the baby has grown up and married, the new spouse becomes part of the family, evoking feelings of concern and protection.

“Baby lust” is the deep-felt hunger to have a child which can easily hit after a woman has cradled someone else’s warm, soft newborn and enjoyed that sweet smell of an infant’s head. (It happens to grandfathers too, as I recently and joyfully experienced. But I got over it when I realized what stage of life I’m in now.)

Being in love with their babies is the characteristic of the bonding phase, which normally occurs right after delivery. New mothers then proceed to lose an average of 700 hours of sleep during the first year.

The average age for menopause is 51.5 years with the agreed-upon definition of menopause starting 12 months after a women’s last period. Major interests for this time are in staying healthy, improving well being, and welcoming new challenges as the nest empties and responsibilities wane. Many believe this is the most productive chapter in women’s lives; they have the maturity and experience without the burdens of reproduction.

Having the ability to do what you want to do, and less interest or need to care for others, is a time which should be savored. In our modern era of the “sandwich generation” (characterized by caring for elderly parents and children who are not yet on their own), the female brain may be stressed in ways similar to the “mommy brain.” Balancing the positives of being post-reproductive with the responsibilities of adults in complex situations does take patience, skill, and energy.

We love, admire, and respect women. As my male brain demands to know, “What would we ever do without them?”


 
Past Health Advice Articles

Dr. Allen Weiss is CEO & President of the NCH Healthcare System. He is board certified in Internal Medicine, Rheumatology and Geriatrics, and was in private practice in Naples, Florida from 1977 - 2000. Dr. Weiss is active in a variety of professional organizations and boards, and has been published in numerous medical journals, including the American Journal of Medicine and the Journal of Clinical Investigation.