Category Archives: The Science of Sex

Brain Circuitry and the Risks of Casual Sex

Once we learn how the brain works, we will be careful selecting a partner in which to copulate.  (Copulation is the scientific term used for sexual intercourse.  Sex is a sensitive topic, but one of the most popular.  We will discuss this topic in the interest of science and medical research.  Our purpose is to provide the information necessary for making better choices.)  Over half of the marriages in America fail.  When I was growing up, adults always said, “Do not have sex before marriage.”  The discussion was over quickly, without discussing the ramifications of poor choices.  I vowed that in my lectures I would give more information.  I am finding that giving the details to young people compels them to make the best choice.  Plus, we take away the desire to do something simply because it is forbidden.

The research we will be exploring was performed by an evolutionary anthropologist named Helen Fisher.  Professor Fisher notes that casual sex is not always casual.  Our brain is similar to an electrical system in a house; it is intricately connected or ‘wired’.  The brain is more complex and sophisticated than a computer.  We are contemporary and liberated today, and it is common for adults to copulate with someone whom they do not have enough compatibility to love.  But after 6 months of casual sex, extreme attachment has complicated the casual sex.  Have you ever heard a friend say, “How did I fall in love with this guy?”  Women have evolved into creatures who experiment with casual sex very well.  But the consequences still exist no matter how cosmopolitan we have become.

Male love is very intense.  Men fall in love more quickly than women and they love very deeply.  Three out of four people who commit suicide after a romantic relationship has ended are men.  Think about all of the stalkers and murder-suicides we hear about on the news.  Many women know how to heal, get counseling, start networking, and move on.  Examine male and female behavior.  Some men have fewer friends than their female counterparts and thus put more into romantic relationships than women.  (We are careful not to generalize, because we have similarities and differences based on gender.  We cannot all fit into a neat package.)  Men tend not to be as expressive as women.  Many women have tightly woven networks with co-workers, biological sisters, mothers, aunts, sororities, and neighbors.  Despite the negative views of female relationships depicted in all of the new ‘housewife’ shows, girls are very supportive of each other.  There is always a sister-girlfriend around when another girl is in emotional turmoil.

Love ’em and leave ‘em is easier said than done for both sexes.  A girl can be the other woman for a while, but then science kicks in and she falls in love.  The sex drive, romantic love, and attachment are three brain systems that are connected.  Romantic love and the sex drive are very closely connected.  Here’s how the brain works.  When you fall in love, you want to start falling into bed with the person.  Elevated levels of dopamine associated with romantic love can trigger testosterone, the hormone of desire (i.e. sex craving).  But the reverse can also happen.  Testosterone can elevate the activity of dopamine and you can fall madly in love with someone you did not intend.  When people sleep around they run the risk of falling in love with the wrong person, getting married, having children, and eventually getting divorced after the roller coaster ride.

Wait!  There’s more information.  When a woman has an orgasm, levels of oxytocin increase.  When a man has an orgasm, levels of vasopressin increase.  Oxytocin and vasopressin are satisfaction hormones.  They give a sense of peace, security, and unity.  If you have enough of these soothing feelings with even the wrong person, you WILL feel attached to them.

Professor Fisher cautions her audience about the use of antidepressants.  In particular, SSRI’s, or selective serotonin uptake inhibitors have an effect on mood and emotional response.  Antidepressants are needed in managing the mental health of people who cannot get out of bed or are contemplating suicide.  Consult your physician before altering your medication schedule.  Do not take an unauthorized drug holiday to experience satisfying sex.

Serotonin-enhancing medications dull the emotions, but can affect romance and attachment in other ways.  SSRI’s dampen the ability to have orgasms, which is a mechanism of attachment.  Having an orgasm is also a form of assessing a mate.  Thus, if a person is not having an organism with their mate on a regular basis the brain is not being flooded with attachment chemicals.  A woman learns a lot about a man in bed.  For instance, is he a self-centered lover who is only concerned about his satisfaction? Is he patient and affectionate?  Does he understand a woman’s body.  The female orgasm does always happen.  In the past researchers called this a maladaptive trait, but now evolutionary psychologists consider it an adaptive trait because it allows a woman to distinguish between Mr. Right and Mr. Wrong.  So, killing a woman’s capacity to have an orgasm destroys the mechanism by which she can assess her potential partner.  The clitoris has over 8,000 nerves.  The only function is feminine pleasure.  (I am thinking about female genital mutilation, FGM, and its capacity to destroy a woman’s sex life.  I will discuss FGM in another session.)  These nerves become less sensitive when taking SSRI’s.  From the male perspective, seminal fluid contains norepinephrine and dopamine, as well as serotonin, testosterone, and estrogen.  All are affected by antidepressants in a negative way.  When a man does not deposit these substances into the vaginal canal, he is not able to influence a woman’s mood positively.  Thus, he is not able to chemically trick her into liking him!  Professor Fisher likens this to taking a medication that blurs your vision.

Now this is the real birds and bees!  I hope you have enjoyed exploring the physiology of sex and all of the hormones involved.  I hope you share this information with your children and grandchildren.  They need to know the exactly how the body works in order to take care of their body.  Do well with this information.


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No More Myths about Human Sexuality

The Role of the Brain in Human Attraction – We really do not know why we pick certain physical characteristics in our quest for mates, but scientists are getting closer to accurate answers.  They have measured every angle of the human face, the symmetry of the bodies of modern dancers, and crafted formulas from the bodies of exotic dancers.  As far as outward features are concerned, the body type for women that is most desired by men is the hour glass shape.  Women work out to preserve that coveted 10 to 12 inch difference between bust-to-waist and waist-to-hip.  Women most prefer that upside down pyramid shape for men, which includes broad shoulders and a cinched waist.  (Look at how men are depicted in an exaggerated fashion on cartoons.)  Of course, we want a potential mate to possess a positive disposition, but we see the physical attributes before getting to know the personality characteristics.  Psychologist Devindra Singh, from the University of Texas studies the waist to hip ratio as it relates to picking mates.  The scientists at UT have manipulated the numbers of enough hips to develop the desired ratio.  I will spare you all of the statistics.  Now this does men that an apple-shaped man or women will not find love.  We are discussing why we like the mates we like.

For those of you who have siblings, think about their past girlfriends or boyfriends.  You should see some similarities in their choices of mates.  If your brother always dates tall, red-headed girls, that is suggestive that there is rhyme and reason to the laws of attraction.  We have all heard the saying, “Opposites attract.”  This old cliché has scientific basis.  MHC or major histocompatibility complex is a term used in microbiology and immunology.  We are all attracted to people with a particular set of genes, known as HMC.  Most of us prefer an HMC that is dramatically different from our own.  This plays an important part in the development of our immune systems.  A mate with a different HMC will allow us all to have strong and robust offspring.  Have you ever seen a very tall man with a short woman or a man of average height with a tall woman?  I have seen computer guys with an affinity for model types.  Opposites do attract.

Women can be very choosey in finding a partner, because they are being competed for.  In the most primitive sense, women looked for stability and men looked for a mate that could reproduce and send their seed into the next generation.  A woman needs a mate who will stick around after she gives birth.  Humans no longer dwell in caves, but the basic rationale behind selecting a mate is very simple.  We all desire to thrive and survive.  Survival truly belongs to the most fit.


I am not here to determine whether or not you subscribe to any Darwinian notions.  However, it is difficult to have a scientific discussion without paying homage to the ideas and philosophies of Charles Darwin.  Let’s set some ground rules.  Evolution simply means a transformation.  The world is constantly evolving or transforming.  Aren’t we different since 9/11?  So, we agree that we have evolved.  I have just saved you an email or a phone call.  You do not have to debate me about my usage of the scientific term ‘evolution’.  (My faith is intact and works very well for me.  Even my spirituality has evolved since becoming an adult.  I certainly do not hold all of the views I held at age 18.)

The goal of these lectures is to explore every angle that science, particularly neurobiology plays in selecting a mate.  Our next discussion will explore how smell can decide who is right for you.  I hope you have fun with this series and apply the scientific facts as you search or the singles seminar sponsored by your place of worship!

Other topics to explore:

Chemicals contained in saliva (Science is involved in an innocent kiss!)

The brain scans of people madly in love are similar to the mentally ill (Yes, you can be love sick.)

Prostaglandins in sperm (Beware of being promiscuous.  You can fall in love with a man who has nothing in common with you.  Intercourse leads to attraction at the cellular level.  Those sperm cells are crafty.)

Brain scans after a traumatic break-up

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The Science of Sex

We will begin a new series that is designed to assist the general public as well as the scientific community about the chemical messages involved in dating, courtship, and sex.  Our goal is always to share information that will assist in having greater knowledge of self.  In the days of my youth, parents would sit children down and have that dreaded discussion about ‘the birds and the bees’, so to speak.  Those conversations were uncomfortable for parents and children.  In professional school I realized that the average person is not equipped with enough information to give a talk on sex and its physiological ramifications.  My mother ordered me to grab a dictionary when we had our talk.  I admired her for her academic posturing, but I had been drawing anatomically correct pictures of every body part for two years prior to our conversation.  Timing is important, too.  I had also been attempting to grow penicillin by placing crumbled crackers and water in a petri dish.  Conversations about natural body processes are still necessary today and I want everybody to be armed with the right information.

Many parents advise girls not to be promiscuous for spiritual reasons.  Do you know that sperm contains chemical messengers that trick a woman into falling in love?  Chemical messengers are also present in saliva.  How is that for a reason to be careful about choosing someone to kiss?  Spirituality is great!  In combination with science, we can help our youth (and adults) to make better choices.  Television is quite graphic today with sexual overtones in commercials and regular shows.  I am excited about this series on the role of science in sex.  Sex is a popular topic of conversation and we should not get our information from pornography or popular magazines.  I had a candid relationship with my grandmother.  She shared that she had given birth to three children before she experienced an orgasm.  Many researchers have studied the differences between the male and female brain activity during an orgasm.  Since the sexual revolution scientists have ceased to be developmentally arrested in the study of the body.  I have seen doctoral theses on a plethora of subjects.  This series should keep our attention as we continue to cover the detailed review of organs and systems.  It is designed to be tasteful, informative, and based on the most up to date research.

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