Polyamory and the Prairie Vole

The Reverend Roger Fritts
February 6, 2005
Cedar Lane Unitarian Universalist Church
Bethesda, Maryland

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I am a heterosexual monogamist. That is to say, I have only one wife, and I am faithful to her. A therapist once told me that my monogamy is because of the death of my mother when I was 14. The therapist said that in my relationships with women I was searching for a mate who would provide the stability and the love that I had lost when my mother died. Because I did not want to lose that love again, I was emotionally adverse to any risky behavior that might jeopardize the relationship. This, the therapist told me, was why I was a monogamist.

For years I accepted this explanation of my mating behavior. However, recently in a book about neuroscience called Mind Wide Open by Steven Johnson, I read about a rodent called the prairie vole. These tiny animals live in a maze of tunnels and burrows on the grasslands of the American Midwest. According to scientists who have studied them, 90 percent of prairie voles live in lifelong unison with a single partner, raising children together in a rodent version of domestic bliss.

Starting in the mid 1980s several researchers including Sue Carter at the University of Wisconsin at Madison, Tom Insel, who was at Emory University in Atlanta, and is now President of the National Institute of Mental Health here in Bethesda, and James Winslow, who also works at the National Institute of Mental Health and is a member of this congregation, studied the brain of the prairie vole in an attempt to understand what caused its unusual fidelity.

There was already research showing that the hormone oxytocin facilitated parent-child bonding in sheep. Oxytocin is found in both men and women. In women it stimulates contractions of the uterus during labor, and it is often given to a woman through an IV to speed up the birth process.

When researchers injected oxytocin into the brains of the prairie voles, the rodents formed even more tenacious bonds. When they injected chemicals that shut off oxytocin receptors, the prairie voles engaged in indiscriminate mating without developing any lasting attachments.


In studying the brains of prairie voles and comparing them to their less monogamous cousins, the meadow voles, researchers discovered that in the faithful voles, the oxytocin receptors over-lapped with dopamine receptors in the area that is one of the brain’s pleasure centers. In the non monogamous voles, the oxytocin receptors were located elsewhere. In the monogamous voles oxytocin receptors were in the reward circuitry of the brain. In other words, it appears that prairie voles brains are designed to make monogamy pleasurable.

Of course, we are in the early stages of understanding brain chemistry. More brain chemicals may be involved in monogamy besides oxytocin. Still, I wonder, can any of this information about the prairie vole’s brain be applied to human beings? It is tempting to give a group of college sophomores a dose of oxytocin to see if they become more monogamous. Furthermore it is tempting to block the oxytocin receptors in another group of sophomores to see if they engage in indiscriminate mating. Of course, ethical rules about such experiments on human subjects make such research unlikely.

Nevertheless, I am tempted to speculate about the possibility that human brains are like the brains of rodents. Perhaps the reason I am a monogamist has less to do with my personal history and more to do with the presence in my brain of oxytocin. Perhaps I was born designed to mate with only one person. And perhaps other people were born designed to mate with several people. Perhaps different humans are biologically predetermined to have different life styles when it comes to mating behavior.

The discussion about what is natural human mating behavior is at least as old as the writings in the Old Testament. According to the book of Samuel, King David had at least 6 wives, and the book of Kings says that Solomon had 700 wives as well as 300 concubines. While polygamy was accepted, there were limits. The sixth commandment says: “Thou shalt not commit adultery .” The tenth commandment focuses in on males saying: “Thou shall not covet thy neighbor’s wife .” In Leviticus and Deuteronomy it says that an adulteress and her lover are to be stoned. Jesus entered the debate 2000 years ago, when in John’s Gospel, Jesus stopped the stoning of a woman caught committing adultery by saying “He who is without sin, let him cast the first stone.”


Modern anthropologists have looked at mating rules in different human groups. For example, G.P. Murdoch looked at 238 societies and found monogamy as the only acceptable marriage system in 43. Most of the 195 non monogamist societies approved of men having more than one wife. However, in most of these polygamist groups men could only have additional wives if they could afford to support them. Because most men could only afford to support one wife, even in polygamist societies, most men are monogamists. The anthropologists found that societies where women have more than one husband are exceedingly rare and even rarer are societies that have group marriages.

Of course our society officially supports monogamy. However, recent testing has documented extra marital activity.

For example, researchers conducted a study into the inheritance of blood groups in America in the mid 20th century. Because a gene from each parent determines your blood type, in most instances only a certain number of combinations are possible. The researchers discovered that 1 in 10 babies’ blood types could not be explained by hereditary factors. The fact that one in ten babies had a different father than the husband of the mother was so shocking to the researchers they kept the results secret for many years.

In southern England in the early 1970s, a schoolteacher assigned a class science project in which his students were to find out the blood types of their parents. The students were then to use this information to deduce their own blood types. Instead, 30 percent of the students discovered their dads were not their biological fathers, to the surprise of both the students and the teacher. The project was discontinued on the grounds that the classroom was not the ideal place for young people to find out this information.

A study published in the Journal of the American Medical Association in 1995, “Blood Grouping Tests in Undisputed Paternity Proceedings,” using blood typing, found that 18 percent of the men who had voluntarily admitted paternity, were not the actual fathers of the children. In still another study, the American Association of Blood Banks says the 300,000 paternity tests it conducted on men in 2000 ruled out nearly 30% as the father.

The use of blood groups for testing for paternity is not very accurate, as O and A blood groups are common. In the last few years more and more parents are paying for DNA tests. A random sample of parents and children in the United States has not been tested. Still, based on blood and DNA testing, researchers guess that between 10 percent and 20 percent of us were not fathered by the man who is the husband of our mother.


This 10 or 20 percent estimate also comes up in a study by an anthropologist at Rutgers University, Dr. Helen Fisher. She surveyed people who said they were in love. Twenty-one percent of the men and thirteen percent of the women said they would go out on a date with someone else when their beloved was unavailable. Twenty percent of the men and 12 percent of the women disagreed with the statement “Being sexually faithful is important when you are in love.”

So it appears that although monogamy is the officially approved form of mating in the United States, a significant minority, perhaps10 percent of women and 20 percent of men, are engaging in extramarital contacts.

Which brings me to this new word Polyamory. Supporters of polyamory say that the word describes a lifestyle in which a person may have more than one romantic relationship, with consent for this choice by each of the people concerned.

According to a paper by a psychologist, there are three main variations of polyamory. In the first, “one relationship takes priority over others,” as in a relationship that allows partners to include outside mates. The original couple considers their relationship to be their “primary” bond, and it is the relationship to which they each devote the most time, energy and loyalty. This is what we called open marriage back in the 1970s.

The next type of polyamorous relationship is one in which two or more relationships are of comparable weight. Each of these relationships are considered to be of importance in the person’s life, and significant time and energy is devoted to each.

The third type of polyamorous relationship is a group marriage: “an inter-relationship of three or more people, in which there is a strong relational commitment between all members.”


Unitarian Universalists for Polyamory Awareness was founded five years ago. They have held informational workshops at our annual Unitarian Universalist General Assembly. The group has not been endorsed by the Unitarian Universalist Association’s Board of Trustees.

As a monogamist, I am uncomfortable with polyamory. I crave exclusivity. I do not wish to have my sacred relationship corrupted by outsiders. I tend to agree with the I Ching, the Chinese book of wisdom written over three thousand years ago, which said: “A close bond is possible only between two persons; a group of three engenders jealousy.”

Indeed, I have written an entire book on the sacrament of marriage, encouraging people to make a serious commitment of fidelity. Having officiated at over a thousand weddings, I have supported couples as they make a public declaration of their faithfulness. I am very uncomfortable with polyamory.

On the other hand, it appears that God or evolution creates life-forms in a variety of ways to increase our chances of survival. For example, some of us have been given genes that cause us to gain more weight than others. The thin among us live longer when the food supply is plentiful, but over-weight people survive longer during a food shortage. Over weight people look sick in a society of plenty, but if we are suddenly hit with a famine they will outlive the thin people.

In the same way, perhaps, ten to twenty percent of the human population has a lower amount of oxytocin in their brains, and therefore, do not suffer from the same feelings of jealousy as the rest of us do when it comes to relationships. These people would be better equipped to keep the human race going in a situation of imbalance between the sexes. They would function better than I would in a society where because of plague or war or natural disaster, there were many more men than women or many more women than men.

So where does this lead me? Although I am married, I realize that everyone is not like me. I believe that the life of a single person can be a satisfying, meaningful alternative to the traditional model of marriage. I believe it is possible for some people to move from one intimate involvement to another retaining a degree of personal independence. Being content with several relationships is possible for some people. It is, it seems to me, possible to have deeply meaningful relationships with others without having one permanent commitment. If the hormone oxytocin encourages us to be faithful to one mate, perhaps oxytocin is not strongly present in the brains of 10 to 20 percent of us, and that this percentage of human beings should not be forced into monogamy.

However, I have observed several couples who have experimented with the idea of trying to have both, a marriage to one person and other relationships. In my experience such arrangements have not lead to fulfillment and happiness. Instead people end up experiencing considerable emotional pain. My experiences are an unscientific random sample. Still, I recall a woman I knew who committed suicide in 1975 after she and her husband experimented with an open marriage. I recall a man who drank himself to death in 1981 a few years after he proclaimed to me the joys of his open marriage. Based my limited, non scientific observations, people in our culture who try to maintain a committed relationship with one person while also mating with others, end up getting hurt and hurting others.


Personally, fidelity makes me feel secure. The thought of infidelity make me anxious. This may mean I have a lot of oxytocin in my brain, or it may reflect the fact that I lost my mother when I was a teenager. It is probably a combination of both, along with other factors.

Whatever the reason, I am part of the 80 or 90 percent of the population who are monogamous. I believe that the traditional marriage, with its rules prohibiting outside sexual involvements, is a winner. In my experience, human beings can have fulfilling lives living in such a relationship.

I realize that traditional marriages fail even with the best of intentions, and even with the most careful preparations. If, despite a sincere attempt, the marriage is disruptive to both partners, the couple should dissolve it. Nevertheless, in spite of its dangers, I believe it is well worth trying.

As news of the research on prairie voles spreads I expect that we will all start getting e-mail spam offering to sell us oxytocin , in pill or injectable form that we can give to our partner as a way of insuring faithful love.

If you get such a junk e-mail, don’t buy anything yet. The research on brain chemistry and attraction is in its very early stages. While oxytocin appears to play a role, others see dopamine as important. Another researcher says that vasopressin receptors are the key. And although much of the circuitry in our brains is similar to that in voles, our two lineages diverged, perhaps 100 million years ago. Therefore what works for the vole probably won’t work exactly the same for humans.

Still, we are starting to learn a little about the love circuitry of the brain, the chemistry of romantic love. My hope is that as we learn more we will be less likely to hurt each other by abuse or betrayal. My hope is that as we understand more about life we will be more likely to mate with each other in ways that give us joy and happiness. If this happens, we will owe a debt of thanks to the two ounce prairie vole and the scientists who study it.

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