Swimming Against Biology
"Think of biology and behavior as dancers -- one leads, the other follows. But which does which, and when? They tug at each other, and in turn are pulled by the music, the fluid melody of the environment. And do we ever know -- can we ever know -- where we are in the dance?" -- Sex on the BrainThere are those who believe that the pace of the dance is quickening, that men and women are moving together to become more like each other, physically and emotionally. In this view, the swirling, circular waltz of biology and culture, an intricate dance in which the steps are chosen, to some extent, by the participants, is an embrace toward a real and equal partnership.We are being orchestrated by the setting asunder of traditional role models, the seers of a new age say, even as science delves deeper into the physiology to lay bare the reasons for our differences, providing understanding, and a means to alter the contrasts between male and female.Breakthroughs in the fields of neuroscience, of the examination of how the brain works, the mapping of its various sectors, and of how the entire nervous system is influenced by chemical, hormonal instigators circulating throughout our bodies are leading to telescopic studies to chart the divergent courses men and women take in their approaches to sex, marriage, reproduction and raising children, and to life's other challenges. For many couples and in male/female relationships in general, observers note, the courses are converging, and, intriguingly, biology is changing as a result.The debate over the extent to which biology influences behavior/culture and vice versa rages on, but it's becoming increasingly evident that we can control our own biology, and thus, if it is our chosen destination, incrementally can nudge society to "fairness."Recently discovered evidence now suggests, for example, that even as adults we can stimulate the growth of new neurons in the brain by exposing ourselves to cognitive stimulation in the form of symphonic music, engaging drama or classic literature, a postulate that had been dismissed to near extinction by the leading investigators of neuroscience. Wonder exists as to what other previously identified impediments to change, to evolution, if you will, might soon be shown to be fictional as well.But we must ask: How much sameness is desirable? The spice of life could become undetectable if the female of the species becomes more aggressive in her approach to attaining life's goals while the male affects a more nurturing persona."For many years, sociologists and anthropologists were reluctant to presume that biology played any role at all [in behavior]," says researcher Alan Booth, of Pennsylvania State University. "Fifty years of biological research have taught us that we have to look at the whole individual. But just because we're looking at biological factors doesn't mean they determine our behavior. It's not a one-to-one relationship. Environment plays a part."In her recently published book Sex on the Brain: The Biological Differences Between Men and Women, author Deborah Blum, a University of Wisconsin-Madison journalism professor and Pulitzer Prize-winning science writer, attempts to locate the biological barriers that might prevent men and women from pursuing equality, as well as those that are falling in the wake of new studies yielding evidence of their permeability. Blum's methodology was to compile the cutting-edge studies into the link between biology and gender traits in an attempt to weigh in on the nature-versus-nurture dialectic, drawing from the disciplines of evolutionary science, anthropology, animal behavior, neuroscience, psychology and endocrinology.Blum says as she considered the subject of biology and environment impacting on behavior she began to focus on questions surrounding power. "I wanted to look at the fact that if indeed we all, men and women, start in a different biological place and bring a different collection of strengths and weaknesses to the table, ones that end up being comparable, does biology explain that?"Blum found that much of the scientific biological evidence is ambiguous, inconclusive or still being refined. In addition, researchers base many of their hypotheses on the evolution of human relationships on studies involving other primates -- chimpanzees, rhesus macaques, bonobos and gorillas.Blum, who won the Pulitzer for a 1992 series exploring the ethical dilemmas of using primates in research, underwent several changes of mind as she researched Sex on the Brain, chief among them the belief that men dominate in most human cultures because they are bigger and stronger. Rhesus macaques, an agile species of Asian monkey with a DNA structure even closer to a human's than is a chimp's, provided a counter claim. In the elaborately sophisticated rhesus macaque "society," the much smaller females dominate by forming bonds with and supporting other females, perhaps eliciting envy from the human female population."Once you get into it, you find other primate societies where males are twice the size of females but females run the show," says Blum. "One of the fundamental things that defines which sex has the power is not the relationship between the males and females, but between males and males, and females and females. In primates, you find that females power bond. Females are there for her in large numbers, and it doesn't matter whether she's wrong or not."On average, a male's brain is slightly bigger than a female's, but outside of a few proponents of bigger is better, among them Charles Murray, co-author of The Bell Curve, consensus is lacking as to what that means.A 1995 study identified one dissimilarity between the workings of male and female brains. It involved testing of the limbic system, which controls split-second reactions and emotional processing. Men's brains were found to be active in an area that has been linked to quick physical response, whereas women's brains were active in a region tied to quick verbal response. Other studies have shown men are more adept at solving spatial problems, while women are better at linguistic skills.Another difference has been found in the measured combination of two neurotransmitters, noradrenaline and serotonin, that control the flight-or-fight response. Serotonin produces a calming effect, noradrenaline, reaction and action. On average, women have a 30 percent higher level of serotonin. Very high levels of noradrenaline were found in extremely violent men.But studies also have shown that biological differences are reinforced throughout the formative years by environmental conditions. For example, a University of Michigan study concluded parents reinforce gender stereotypes by attributing success at math by boys to natural talent and by girls to hard work, and by then emphasizing that boys need to learn math, computer science and mechanical skills, whereas girls should focus on English and biology."Everything is biologically determined at one level, but its expression is always an interaction with an environment," Blum quotes Kim Wallen, a professor of psychology at Emory University in Atlanta. "Apparently, to admit that males and females come with different predispositions was regarded as endorsing the worst kind of social discrimination. The boundaries between genders are naturally quite blurred. There are very few things that only males or only females can do. That, however, is not the same as saying there are few things that only males or only females are likely to do.""The point is not whether there are differences," anthropologist Andrienne Zihlman, of the University of California-Santa Cruz, tells Blum, "but that the differences be approached and studied without value judgments."In 1935, Dutch scientists isolated the steroid hormone testosterone, bringing to resolve decades-long speculation that the male body contained some kind of biological magic and launching what Blum concludes has resulted in "The Big T" (scientists refer to testosterone simply as "T") becoming the "most studied hormone" in history.Both sexes have testosterone, but on average about 10 times as much -- still only sixty millionths of an ounce -- circulates in the average male's body as in the average female. It's made by men mostly in the testes, and by women in the adrenal gland and ovaries.Each of us has a basic T-level, but it fluctuates on a daily cycle and in response to daily events. More than a decade ago scientists discovered that testosterone levels could be accurately measured by taking saliva samples, and since then the number of studies of the hormone have mushroomed. The research generally concludes that a high T-level correlates to edgy, assertive, aggressive behavior.Testosterone-driven males have been on the live-fast-and-die track genetically dating back to our prehistoric ancestors, who hunted and gathered and flit from female to female in never-ending battles to reproduce, while women raised and cared for the young."Testosterone rises before a competition, and it doesn't matter whether you're about to play chess or football," says Blum. "It doesn't have to be physical, and if you won either, it would stay up. The same is true for men sitting around watching the game. That's why they have all those horrible fights at soccer games in Europe, I suppose."In one study of 700 Georgia inmates, researchers found that car thieves and burglars had lower T-levels than armed robbers and killers, and that high T-level inmates tended to be rule-breakers who enjoyed confrontations.Booth was involved in a 1993 study that found men with higher T-levels were more likely to have bad marriages, were more likely to divorce, often because they were unfaithful or physically abusive."But there were a lot of men with higher levels of testosterone who had good marriages," Booth cautions. "Maybe it was because of their early family environments, that they got a lot of attention and affection from their parents so they were able to control their behavior more. In a lot of cases it may be that testosterone doesn't always work that way. You expect an individual to behave in a dominant way and it doesn't always happen."Another study found that single men have higher T-levels than married men, that testosterone levels dropped for men who entered stable relationships, dropped again after marriage, again after they became fathers, and could be lowered in males who provide substantial care for their children. They rose for men who divorced, for those whose marriages were becoming unstable, for those who ended relationships.What researchers don't know, what they conceivably could debate ad infinitum, is primarily whether high testosterone levels result in aggressive behavior, or from it.Booth and his colleagues at Pennsylvania State University are concluding a three-year study that might shed light on that very question. Researchers looked at 400 families, 200 of them with two siblings of pre-adolescent age and 200 with two adolescent children. They monitored hormonal levels while attempting to gauge the "quality" of the familial relationships. Booth also studied the development of recreational and career interests by the children. The results are due in about one year.Other researchers have shown that high-testosterone women tended to be less likely to have children and more likely to have careers in challenging, predominantly male-oriented fields, whereas lower-testosterone women had more interest in children, in cooking, in dressing up, in dressing up their homes. Overall, high-T daughters tended to be children of high-T mothers."That raises a familiar question of feedback between biology and behavior," Blum writes in Sex on the Brain. "Is this a genetic predisposition of some kind, passed along from mother to daughter? Or did the high-T mothers treat their daughters differently -- pushing them toward more competitive pursuits -- than the low-T mothers?""We're catching these youngsters as those interests are coming to fruition," says Booth of his ground-breaking study. "We're going to have real good information on young girls' interests in occupations, and how they're influenced by biological factors and family factors. It may be that when we get a whole lot of things together, like parents influencing girls to try non-traditional things and having role models that are non-traditional, plus a little higher levels of testosterone, we may find that these things interact."Blum ponders whether "non-traditional" families, pairings in which both parents work and the males share roughly equally in the caring for offspring and maintenance of the household, females with slightly raised T-levels and males with slightly lowered ones, will fuel the revolution to a more just and equal society. She asked that question of evolutionary biologist Judy Stamps. "As Stamps reminds me, my marriage and those of my friends follow a pattern for educated, middle-class American couples. It's nothing like the worldwide majority trend; there's no great unified rush toward complete equality," Blum writes. "There's just no real evolutionary pressure, Stamps says, for a species-wide change."So Blum touts the individual's capacity for change, citing a southern California study of persons suffering from obsessive/compulsive disorders. A comparison was done in which half of the patients received Prozac and half underwent behavioral therapy in which they were asked to delay, for just five seconds, engaging in compulsive acts such as the repeated washing of hands. They then were asked to delay the compulsion for a longer period of time, and so on, for progressively extended periods."They were able to completely rout out the behavior," Blum reports. "A series of MRI [Magnetic Resonance Imaging] scans were performed and they found that their brains had physically changed, the structure, the neuro-transmitters, simply by changing their behavior. That's a beautiful example of how powerful it can be. The ramifications are huge."Recognizing that evolution is a "great conserver," that nature doesn't discard what works, it's likely that whatever progress is made toward bridging the inequality gap between men and women could be slow in coming."We're on the cusp of this change, which maybe is influenced by biology," says Blum. "We want to push and we want more."Can I recreate myself as a gentler, kinder person? Can you play with the core of who you are or just the periphery, the room itself or the furniture in it?" Blum poses. "It's clear that we can do some re-arranging, some remodeling if that's what you want. I agree with Lillian Hellman, who wrote that we're always unfinished. That's the most encouraging message in the world."