Access to no-cost birth control does not make women any more likely to have multiple partners. (Photo: Beatrice Murch/Flickr)

Although the current debate over contraception coverage has largely been framed in religious-freedom terms, the controversy clearly reflects a continuing discomfort with female promiscuity, at least among certain segments of society. Provocative statements by Rush Limbaugh and Mike Huckabee make the subtext of last week’s Supreme Court decisions perfectly clear: No subsidies for sluttiness.

It turns out the assumptions behind such declarations are utterly wrong: A study released this spring found access to no-cost birth control does not make women any more likely to have multiple partners. This raises the question: What are the deeper psychological impulses that underpin these deeply held, but factually unsupported beliefs?

A newly published study provides a provocative possible answer. A research team led by psychologist Michael Price of Brunel University in Middlesex, England, provides evidence that these attitudes are grounded in outdated but still emotionally potent attitudes about paternity and economic dependence.

Price and his colleagues have come up with what they call “the female economic dependence theory of anti-promiscuity morality.” It states that “opposition to promiscuity arises in circumstances where paternity certainty is particularly important,” and predicts it is likely to arise “in environments in which women are more dependent economically on a male mate.”

"Opposition to promiscuity was significantly lower among heterosexual females with higher incomes, and significantly higher among heterosexual males who made more money relative to their partners."

In other words, these feelings are a remnant of some of the oldest impulses in our evolutionary history: A man’s fear of getting stuck with the tab for raising another man’s child, and a woman’s fear of losing her man’s financial support because he suspects her child isn’t his.

The fact that birth control—a very recent development, in evolutionary terms—drastically reduces the odds of unwanted pregnancies does not penetrate the encrusted region of the psyche where these largely unconscious fears circulate.

Like so many evolutionary psychology theories, this one is difficult if not impossible to definitively prove. But Price and his colleagues describe two experiments that provide evidence in support of their concept.

The first experiment featured 656 Americans recruited online to participate in a “relationship attitudes” survey. They first responded to a series of statements regarding female economic dependence, expressing their level of agreement with such assertions as “Of the women I know who are in long-term heterosexual relationships, most rely financially on their male partner.”

Next, they revealed their ideas about promiscuity, responding to such statements as “It is fine for a woman to have sex with a man she has just met, if they both want to.” Finally, they described their political ideology and religiosity.

The results shows that “perceived female economic dependence was moderately predictive of opposition to promiscuity,” the researchers write, “and this relationship remained significant after controlling for the effects of age, sex, religiosity, and conservatism.”

The second survey, also conducted online via Amazon’s Mechanical Turk, featured 4,626 Americans from all across the country. It replicated the results of the first study, and found that “anti-promiscuity views were strongest among those who were themselves involved in (or likely to become involved in) a relationship entailing high female economic dependence.”

“Specifically,” the researchers write, “opposition to promiscuity was significantly lower among heterosexual females with higher incomes, and significantly higher among heterosexual males who made more money relative to their partners.”

Interestingly, the researchers found the “perceived female economic dependence in one’s social network” was an even greater predictor of opposition to promiscuity than one’s personal economic circumstances.

“These results suggest that moral views about promiscuity are influenced ... by the norms that prevail in one’s community,” they write.

Religion and ideology play a role in reinforcing these ethical codes, of course. But Price and his colleagues argue that, rather than focusing on their influence, “a more interesting question is how these moral systems became so opposed to promiscuity in the first place.

“It is plausible that conservative and religious ideologies tend to oppose promiscuity because they, themselves, developed in environments with high female economic dependence on males,” they argue.

If this theory is correct, we’re in for a dramatic shift in sexual attitudes over the long run, as women begin to earn more than men. But for now, primal fears based on traditional gender roles may be at the root not only of crudely expressed political opinions, but also high-profile court rulings.