An Unromantic but Compelling Theory About Sexual Motivations

Some years ago, we published a theory that people don’t like. I can sympathize with their reaction. I don’t really like it either. It’s about gender and sex. (Incidentally, I use ‘gender’ to refer to males/females/others, and "sex" to refer to, well, doing it.)

The first time I encountered the idea for this theory, I had an immediate negative reaction. Perhaps ironically, this was in some writings by a feminist historian, Nancy Cott, whose works I read and admired. She was grappling with why women in the Victorian era were so sexually prudish. (They were much more prudish than women before or after.) She made some intriguing points.

As is well known, the Industrial Revolution made obsolete most of women’s traditional work, such as making clothes. (The textile industry was an early driver of the Industrial Revolution.) As a result, the 1800s had “the woman question,” as in what is the proper function of women in society, now that they no longer had to do all that spinning, weaving, canning, and other chores.

Cott said women were reduced to using sex appeal as their main ticket to a good life through marriage. As she put it, if sex is your only asset, you need the price to be high, so you want to restrict the supply. I didn’t like that theory and initially rejected it (as in my book Meanings of Life).

Cott just made that as a side point, but it got me thinking. It has some potentially good points when you get past the initial emotionally negative reaction. Our sexual economics theory elaborates her insight.

At that time, theories about sex mostly invoked either biology (evolution) or political science (feminism), so turning to economics was a new direction. Essentially, with sex, women are the supply, and men are the demand. For women, sex has a market value in that it can be exchanged for other resources—love, commitment, or even money. Male (hetero) sexuality does not have that kind of value. (Male sex workers mainly get their money from male clients.) A man who wants to fund his drug habit or manage his serious debts by having women pay him for sex usually will need a plan B.

Early in my career, I read Marcia Guttentag and Paul Secord’s book Too Many Women? A main theme is that around the world, a society’s sexual morals and practices shift in proportion to the gender ratio. And the shift totally fits the supply and demand theory. Sometimes there are more men than women, such as selective migration (America’s Wild West) or selective abortion/infanticide (one-child China; some hunter-gatherer societies).

Also, in polygynous societies, which included many past societies, women are scarce because the rich men marry multiple ones. In these cases of a scarcity of women, the demand far exceeds the supply: so the price of sex is high. Men either pay for sex on a case-by-case basis, or they make a heavy lifetime commitment to a permanent partner (a wife).

In contrast, when women outnumber men, such as after a major war that has killed off many men or on today’s American college campuses, the supply exceeds the demand: so the price of sex is low. There is plenty of premarital and extramarital sex, and the woman cannot demand much in return.

Essentially, there is a sexual marketplace. Men must give women some other resources (commitment, love, respect, expensive dinners, prestige, money) in exchange for sex. The price of sex reflects market conditions, as in how much a woman can get in return for entering into a sexual relationship. A high price for sex favors women. A low price favors men.

The sexual revolution was a kind of market correction. Women want sex, too, of course, though perhaps not as much as men. If Cott was right, the women of the 1800s had to keep the price high. This imposed a cost on them by denying themselves many orgasms, yet it was worth it. But when women moved into the male-created society and started earning their own money, they were less dependent on husbands, so they didn’t have to pump up the price of sex as much.

I am inclined toward a romantic approach to life in general and love stuff in particular. Economics is a decidedly un-romantic discipline. Applying economics theory to sex kind of grates on me. But the evidence in favor of this is overwhelming. I "got over myself" and came around to realizing that any grand theory of relevant human behavior has to make room for sexual economics.

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When we started looking around at the evidence, we were struck by how many phenomena seemed to fit these patterns. If you want to check out the evidence, see the references at the end of this post.

Let’s be clear. Many factors influence sexual behavior, including many that have nothing to do with sexual economics. This is just one factor among others. But it seems to explain and probably drive a great deal of what actually goes on.

My colleague Kathleen Vohs was a co-author on the original theory paper and various others. She also did some lab work to test the theory. Once, she mentioned to me that her research assistants had reported a curious pattern to her as their general impression.

At the end of the experimental session, they would explain to each research participant the purpose of the experiment, including giving a brief explanation of sexual economics theory. The research assistants had the impression that when they explained this to the attractive women in the research sample, these women usually understood it right away, and they said yes, that’s how the world works.

In contrast, the less attractive women did not think this was true at all and sometimes were shocked that anyone would even think such a thing. These are hardly systematic, well-replicated data, but it would make sense if the students’ off-the-cuff impressions were correct. Attractive women might be most attuned to the sexual marketplace because they derive the most benefits.

There is a broader implication here. As a generalist, I have read many different research works of literature on many different topics and tried to come up with a theory for each that fits the current knowledge. One lesson the generalist learns early is that reality is not the way we fondly imagine it should be.

Sometimes one’s hopes are justified, other times not. I have set my life goal to figure out as much as possible. A big picture cannot be good if some of the major pieces are wrong, so one has to get used to accepting things that one doesn’t really like. My romantic self would prefer if sexual economics theory were not true. But it sure seems to be true.