Since the beginning of time as we know it, love between the sexes has been the driving force of our survival as a species.  Countless stories have been written about it, wars have been fought over it, and yet the relationship between men and women still remains one of life’s greatest mysteries.

Men and women are irrevocably attracted to one another and can’t seem to live without each other, yet both men and women seem perplexed about what makes the other tick.  Women often become frustrated with their men and wonder why men can’t be more like them.  To many women, men seem incapable of giving them the emotional support and commitment they are seeking in a relationship, yet men are equally exasperated with women and often puzzled about what women want from them.

In the last fifty years gender roles have changed dramatically, adding more confusion to our expectations, yet the biology of sexuality and the innate physical, mental and emotional differences between men and women have not changed in thousands of years, and it is not likely that they will dramatically change any time soon.

In his fascinating book, “What Could He Be Thinking?”, Michael Gurian describes the science behind the differences between men and women, reflected in how their brains function.  Much of the mystery can be dispelled when we understand that the male and female brain operate very differently from one another, and that our hormones dictate much of our behavior, both physically and emotionally.

Recent research has demonstrated, through MRI and PET scans of the brain, that men and women’s brains function very differently.  For example, when processing emotions, far more areas of the brain were active and lit up on the screen in women’s brains than in men’s.  The female brain has 15% more blood flow than the male brain with more neural pathways connecting different parts of the brain, simultaneously engaging parts if the brain that are not stimulated in men.

Men are more capable of spatial skills, including mechanical design, measurement, direction, abstraction and manipulation of physical objects, while women are more verbally skilled than men.  The corpus callosum, a bundle of nerves connecting the right and left hemispheres of the brain, is 25% smaller in men, making it more difficult for men to make language out of their experience.  In fact, studies show that men use about half the amount of words that women do.  Women love to talk about their emotions, while for most men, talking about their emotions is often difficult and even stressful as evidenced by an increase in the stress hormone cortisol when engaged in this activity.

In women, the secretion by the hypothalamus of the hormones serotonin and oxytocin is greater than in men. Serotonin calms us down.  Men tend to react to a perceived threat with a physical response, while women will try to talk themselves out of a stressful situation.  Lower levels of serotonin and oxytocin in men also result in less acute hearing, affecting communication.  Men also possess less aural neurons so loud noises don’t bother them as much as they do women.

Oxytocin is the bonding chemical.  The higher the level of oxytocin, the more empathic and less aggressive the individual will be.  Oxytocin also links the verbal centers in the brain and stimulates a nurturing response with others.  Higher levels of oxytocin in women enable them to be good mothers and respond to the emotional needs of their spouse, children and friends.

During sex the increase in oxytocin causes a woman to bond intensely with her partner, creating romantic attachment.  About the only time a man experiences a surge of oxytocin is during orgasm which allows him to bond with his partner as well.  However, after orgasm, a man’s oxytocin levels return to their normally low levels, while the woman’s levels remain consistently higher than the man’s.  This is why a man may be compelled to say, “I love you” during sex, but may not feel like saying it much afterwards when the woman is longing to hear reassuring words of love and affection.

Men have different bonding strategies than women.  In general, men choose a physical activity such as participating in sports, playing poker or hunting. For women, sharing their experiences verbally helps them to bond with others.

Much of the more aggressive, sexual and action-oriented responses in men are caused by higher secretions of testosterone signaled by the hypothalamus in the male brain.  A man’s system is dominated by testosterone, with 20 times more of this hormone than is found in a woman’s system.  In women, testosterone levels usually increase only around the time of ovulation, causing interest in sexual bonding.  Athletes, soldiers, and CEO’s tend to have more testosterone, both in men and women.  Competition also causes increased testosterone levels.

Deep in the limbic system of the brain where our primal urges reside, lies the amygdala which handles many of our emotions and aggressive tendencies.  The amygdala is larger in men than in women leading to increased aggression.  Compared to women, there are also less neural pathways in the male brain linking to the cortical parts of the brain that regulate emotions and moral decision-making. This may explain why men and women think differently about ethics, empathy and morality.

The hippocampus is the memory center of the brain and is larger in women than in men.  There are also more neural pathways from the hippocampus to the emotive centers in the female brain. Women tend to remember more physical and emotional details of an experience which may be linked to the primal need for these abilities in childrearing, while men did not need to remember such things to hunt or build.

A woman’s brain doesn’t rest from stress the way a man’s does. A University of Pennsylvania study showed that men take mental naps when over-stimulated.  They can zone out in front of the TV or engage in a physical activity to switch focus from a distressing event or emotion.  When the female brain does rest, more of its neurotransmitters stay lodged in the cingulated gyrus, an important feeling and emotion center of the limbic system.  When a man’s brain is at rest, more neural transmissions occur in the brain stem, the home of the fight or flight response.  It is fascinating to note that brain scans of couples in love show a highly active cingulated gyrus in both sexes.

Michael Gurian points out that one major difference between men and women is how they develop self-worth.  By nature, females are born with a sense of self-worth through the onset of menstruation and childbearing.  Men, however, must earn their passage into manhood through the tests and challenges of life experience.  There is a biological drive within every man to find his calling and earn respect through his actions.  Unlike women, men tend to search out ways to become wounded and make games out of it with other men.  They seek to show bravery and courage by accomplishing the impossible.  A man’s pursuit of self-worth and personal power is such a life-driving force, that in most cases it takes priority over intimacy.  If a man has developed a strong sense of self as a man, he is better able to participate in a healthy intimate relationship with a woman.  She will feel his strength and derive nourishment from it.

In the past and in more primitive cultures, society was set up to help men on their quest for self-worth.  Tribal rites of passage such as the hunt or vision quest were arranged for young men to find their calling and their courage.  Fathers and elder men mentored these youth, teaching them the moral codes of honor and how to conduct themselves as men.  In today’s society, we no longer provide young men with a structured path to manhood.  Boys of divorced families where the father is often absent are especially disadvantaged and can develop violent behaviors or confused sexual identity without the guiding hand of a male mentor.

Another important factor in a man’s ability to have a healthy romantic relationship is the successful biological and psychological separation from his mother.  A domineering or controlling mother who doesn’t allow her son to individuate as a self-reliant man will cause her son to fear enmeshment in relationships with women and resist commitment.  Women are also influenced by their relationship with their fathers, fearing distance and abandonment from men she partners with if this was her experience with her father.

The degree of “maleness” a man’s brain will exhibit is largely determined when the brain is forming in the womb.  The greater the testosterone secreted around the developing fetus, the more he will exhibit these male brain tendencies.  About 25% of men are what Michael Gurian calls “bridge-brains.”  These men exhibit more emotional,  nurturing and verbal ability than other men, and seem to be what many women are looking for in a man.  A woman’s sexuality is also determined in utero and, depending on the hormonal environment, can produce a more masculine bridge-brain female.  Gurian points out that in order for relationships to be successful it is important that both men and women understand their differences and accommodate them.  He calls this “intimate separateness.”

Since the feminist movement of the sixties and seventies, women have developed more abilities outside the home stimulating the development of more masculine traits, while men have been forced to explore the more feminine aspects of emotions and nurturing behaviors.  In his book, “Intimate Communion,”  author David Deida explains how these new gender roles have helped to neutralize the natural sexual polarity between men and women.  Women who desire a more sensitive, nurturing man may also miss the strong, passionate masculinity of the goal-driven male that was more prevalent in previous generations.  Men may be confused by a woman’s aggressiveness and desire to control him.  He walks a fine line between being the man she wants and offending her sensibilities.  According to Deida, intimate communion is achieved when women learn to be more comfortable with their feminine essence and men embrace their masculinity, while both partners maintain an appreciation for the other’s needs.  It appears that the recent brain research presented by Michael Gurian would support this more conscious way of relating.

The dance between male and female polarity will always be the primary motivating force of life, and with consciousness, can provide a vehicle for creating a fulfilling union.