Barash and Lipton: "The Myth of Monogamy"

"Myth of Monogamy: Fidelity and Infedility in Animals and People," By David P. Barash and Judith Eve Lipton;
W. H. Freeman; 227 pp.


By David Abel  |  Globe Staff  |  7/22/2001

This is not the sort of book you want to be seen reading in public.

There are no pornographic pictures inside, the author isn't wanted for blasphemy, and the language couldn't be further from the Marquis de Sade. In fact, this compact scientific volume is written in such clinical detail that it might border on mind-numbing, if not for its subject.

But "The Myth of Monogamy" is better read in solitude. I should know. Over the course of several days, in airports, restaurants, and parks, I read the book and watched as people glanced at the incendiary title on the jacket and eyed me suspiciously.

Of course, the ultimate message of David Barash and Judith Eve Lipton's work is nowhere as apocalyptic for those married or considering marriage as the title might suggest. Still, its findings do not bode well for couples who earnestly believe wedding vows automatically translate into lifelong monogamy.

The husband-and-wife team of Barash, a psychologist with a doctorate in zoology, and Lipton, a psychiatrist, write in Darwinian detail but are breezy enough so not to lose the lay reader. It also helps that they are straightforward. In their opening paragraph, they paraphrase the anthropologist Margaret Mead, who once suggested that monogamy is the hardest of all human marital arrangements.

"It is also one of the rarest," they write. "In attempting to maintain a social and sexual bond consisting exclusively of one man and one woman, aspiring monogamists are going against some of the deepest-seated evolutionary inclinations with which biology has endowed most creatures, Homo sapiens included."

In example after example, using recent research based on the "DNA fingerprinting" of hundreds of creatures ranging from orangutans to red-winged blackbirds to rats, Barash and Lipton find widespread evidence of infidelity in many animals previously thought to be monogamous. In all, they say, out of about 4,000 mammal species, only roughly 3 percent form "reliable pair-bonds" (most of which are not reliably monogamous), and of primates fewer than 15 percent practice a variation of monogamy, what they call "social monogamy," or marriage with furtive affairs.

Monogamy is similarly rare in human societies. In study after study, Barash and Lipton write, researchers have overwhelmingly found that monogamous relations are far more the exception than the rule. Of more than 200 human societies, including Indian tribes in North and South America, clans in West Africa and the Arab world, and peoples throughout Oceania, more than 80 percent practice a form of polygamy.

The institution of monogamy, as underscored during Bill Clinton's presidency, is hardly pure in America either. In response to surveys, which probably underreport the phenomenon, about 40 percent of men and 30 percent of women in the United States acknowledge having had at least one extramarital affair.

While male species as well as men typically tend to be more eager for multiple sex partners, which the authors attribute primarily to the biological desire to spread sperm and increase the chances of producing offspring, they note more unexpectedly that female species and women are often just as eager to sleep around: "Freud spoke more truth than he knew when he observed that female psychology was essentially a `dark continent.' "

The authors' explanation for why female species as well as women often engage in extramarital sex includes a desire for sperm competition (the more mates, the more sperm, the more probable that offspring will be better endowed); for personal benefits that come from suitors, such as food, protection, and extra help in raising offspring; and for the chance to "prospect" for a better mate.

There are examples in nature of animals that do practice monogamy. They include a few species of bats, some foxes, tiny monkeys known as marmosets and tamarins, the giant otter of South America, a few species of seals, and several small African antelopes. "A pitiful list," according to Barash and Lipton.

Even with those, the authors write, researchers can't be certain. After all, like humans, most animals who are "socially monogamous" don't advertise their infidelities. Such trysts are carried out almost entirely on the sly, when the mate is tending babies or out hunting.

Another problem is that scientists often have to go to great lengths to do their research. It is dangerous to try to collect semen produced by a chimpanzee, and gathering information about a human being's sex life can be unreliable, especially when done through questions and answers.

Nevertheless, there are obvious patterns that have emerged after centuries of scientific observation - and they all point to humans falling outside the monogamous camp. Like humans, those species that don't maintain strictly monogamous relations usually produce males about 10 to 15 percent larger than females, males that mature sexually later than females, males with proportionally large testicles, and males who have a tendency to be more violent than women.

"Don't be deceived, however, into thinking that human beings can easily be pigeonholed as to their `natural' way of living," Barash and Lipton caution, though adding: "A Martian biologist sent to earth to describe its various life forms would have little doubt, based on sexual dimorphism [significant differences between males and females in size and genitalia] alone, Homo sapiens is mildly polygamous."

Of course, as the authors note, there is an important difference between animals and humans. Unlike nearly all other creatures, we have the ability to act against our instincts or, rather, deliberate among options and choose what is in our best interests, even if it's not immediately gratifying.

In fact, the authors believe monogamy is a social advance. Considering how even among animals adultery often leads to jealousy, violence, sexually transmitted diseases, social estrangement, and divorce, it's not surprising that humans in more technological societies choose to maintain at least socially monogamous relationships, they contend.

Monogamy, they write, is also more democratic. It may be a neat argument that fits all too well with our Western values, but Barash and Lipton believe monogamy is as rational for humans as polygamy is instinctive. Given the emotional, financial, philosophical, and biological complexities of life, they effectively argue, the stability of monogamy makes sense.

"The perfect fit of a good monogamous marriage is made, not born," they write. "And despite the fact that much of our biology seems to tug in the opposite direction, such marriages can in fact be made. It is an everyday miracle."

David Abel can be reached at

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