New Under the Sun:
Volume 5, Issue 12
The tragedy that is Darfur seems unending. In this month when we are thinking about giving to others, I hope you will consider donating to the Darfur relief efforts. It is estimated that hundreds of thousands of men, women, and children have died due to the conflict and genocide. Millions have been displaced. Sadly, Darfur is not the only place in need of help, so if not Darfur, then please donate to another charity of your choice. No place is truly isolated in the 21st century. What happens in one region has a chain reaction effect on other regions since all regions are ultimately, even intimately, interconnected.
Book Review: Culture, while important, is actually just an overlay on biology. Although there are many who will disagree with that statement, an analysis of the facts will show that biology does, indeed, provide the dominant underpinnings for who and what we are. This does not mean that we are purely instinctual organisms with no control over outcomes. But it does mean that there is less flexibility in human nature and behavior than many social critics would wish. There are biological differences. These differences are the result of millions of years of natural selection. Unless the differences are totally insignificant (and do we have enough information to determine that?), the differences increase the probability of future success in the genetic stakes. The fact that there are differences does not mean that inequality is necessarily inevitable because “sameness” and “equality” have no necessary relationship. Perhaps a better term than equality would be parity. For instance, two jobs may be quite different, but be in parity because they require equivalent years of training and experience to do well. The way in which two individuals analyze a problem may be quite different, but if they both achieve a successful solution, their methods are in parity. Different does not and should not mean “less than.” This leads us into this month’s book review: The Female Brain by Louann Brizendine, MD.
Despite the wishful thinking of some social critics, women and men have significant differences. These differences need to be acknowledged and incorporated into a full expression of what it means to a successful individual in modern society. The brain is the seat of reason, emotion, and bodily control. Therefore, it makes sense to focus on this organ to understand many of the basic differences between men and women. Brizendine is a neuropsychiatrist with a background in neurobiology. Her practice and research have been devoted to understanding the ways in which the brains of men and women are both similar and different. The Female Brain is a collection of the insights gained from her work, highlighted with vignettes from her patients, students, and research subjects. What follows are a few highlights from the book.
Beginning with the physical structure of the brain, we find that while male brains are, on average, heavier, even when controlling for body weight, female brains have more connections. Diving into the brain shows that for some structures, the female version is larger, but for others, it is the male’s that is larger and has more connections. For instance, the hippocampus, the seat of emotions and emotionally-charged memories, is larger in women, whereas men have more than double the amount of brain tissue devoted to aggression, action, and sex drive. This makes good evolutionary sense. Females must be acutely tuned-in to the needs of infants and toddlers. This is not as necessary for males who have to be more aware of challenges to their status and opportunities for mating.
This differentiation into male and female brains begins about eight weeks into gestation. Prior to this point, the brain (and the body plan) is essentially female. It is not until testosterone floods the embryo/fetus that a male body plan and brain are set into motion. One result of the hormonal flush is that the male brain loses language connections, but develops more connections associated with aggression and sex. In later years, this means that women, on average, use three times the number of words each day that a man does, but that men think about sex once every minute, whereas women think about it perhaps once each day; just a slight gender difference.
The higher level of estrogen flooding a toddler girl’s body and brain not only helps prepare her for later reproduction, but appears to increase her sensitivity and empathy to the emotional cues provided by others. Testosterone seems to inhibit these behaviors. This may be why autism and Asperger’s syndrome is eight times more likely to occur in a boy than a girl.
Oxytocin is a powerful bonding hormone whose production is stimulated by estrogen. This is great for a mother bonding with her newborn. However, when we look at some of the odd, even disturbing couplings in society, it appears to me that oxytocin can lead a woman into a“Midsummer Night’s Dream” madness with the hormone behaving much like Puck’s fairy dust, causing a woman to fall in love with the first “man” she sees. Maybe this accounts for all the sitcom couples where the woman is attractive and the man is not.
Oxytocin is also a major factor in the bonding that occurs between girls during puberty. This serves an important evolutionary purpose that can still be seen among our close relatives, the bonobos. What inexperienced mothers need most is not a male, however doting a father he may be, but an experienced, older female who can help the new mother successfully navigate the birthing process and provide guidance in raising the infant. Women are more emotional than men. This does not mean that men are somehow superior. It is simply a biological fact that the average woman is more attuned to and more open to expressing her emotions than is the average man. Brizendine cites research comparing brain scans of men and women shown emotional images. Two areas lit up in men’s brains, but nine areas lit up in women. Women need to be attuned to the slightest emotional change of their infants and children if they are to successfully raise them. Mothers who were not attuned would have had their genes selected out of the gene pool. Millions of years of natural selection have created the differences we see between men and women. They are differences that have provided their offspring with the best chance of success.
This review has provided just a taste of the material covered by Brizendine. Parents who are tearing their hair out will find her chapter on the “Teen Girl Brain” especially useful. Couples who want to improve their sex lives will enjoy reading “Sex: The Brain Below the Belt.” Brizendine points out that women cannot really enjoy sex and have an orgasm unless the amygdala, which controls the response to fear or anxiety, is in neutral. So try a little tenderness and relaxation. For those who are familiar with the field of evolutionary psychology, there is little new information here. However, for those who are not or who have wondered, like Henry Higgins, “Why can’t a woman be more like a man?” this book is an enlightening, enjoyable read.
AnthroHealth Tip of the Month: This month, daylight seems brief, ephemeral. Hence the many and various celebrations of lights. It is also the beginning of the seasonal depression known as Seasonal Affective Disorder. As regular readers know, SAD, and depression in general, are associated with vitamin D deprivation. Little or no UVB radiation exposure means plummeting vitamin D levels. The 1,25 OHD version of vitamin D is a hormone. As Brizendine points out in her book, hormones are powerful. Researchers have found vitamin D receptors on virtually all tissues in the body including the brain. It should not be surprising to find that inadequate levels of this hormone should have wide-reaching negative effects on health, including mental health. In order to combat this and enjoy life more, consider taking vitamin D supplements of 2000 IU/day. The vitamin D needs to be D3 or cholecalciferol and should be taken alone; that is, not as part of a calcium, vitamin A, or multivitamin tablet.
May the end of this year be the beginning of a wonderful new year.
© 2001-2009 Kathleen E. Fuller, PhD. All rights reserved.