Marriage, according to those who habitually preface the word with "traditional", is a collaboration. With complementary roles, filled as predictably by one woman and one man as peanut butter fills the gap between two slices of white bread.
If you encounter somebody clinging to this view of marriage in which women happily traipse down the church aisle into economic dependence on their menfolk, then I'm sure you can predict their views on sex and the thousand other issues that inhere to sex:
Sex education? Abstain until marriage, 'cos true love waits.
The pill? Okay if you're using it to control your acne.
Abortion? Causes all those calamities the greenies like to pin on climate change.
Okay, my clumsy stereotype grows unkind. My point is that more often than not women's economic dependence on men is bundled up with strong views against sexual promiscuity.
But why? Are economic dependence and anti-promiscuity morality both symptoms of the same cause? Patriarchy, perhaps? Or does one bring about the other? A new study in Archives of Sexual Behaviour suggests that economic dependence might lead to anti-promiscuity views.
Paternity no laughing matter
Visiting friends or relatives in the neonatal ward isn't the place to crack jokes about paternity. In fact, most people, especially relatives of the new mum, go to great efforts to comment on the newborn's likeness to the guy who thinks he's dad.
Paternity strikes such a raw nerve with men because they can never be truly sure that they're the father. At least they couldn't until recent technological developments in DNA analysis made it possible.
And yet throughout our evolutionary past, some men thought they were working hard to raise their own genetic progeny where they were actually rearing the young of another. Men who were suspicious, jealous and not prepared to raise another man's children might not have won any nice-guy prizes, but they did ensure their hard work contributed to the success of their own genes. Including any genes that disposed them to jealousy and vigilance about paternity. Unfortunately, we are all descended from many such men.
Today, humanity's long history of insecurity over paternity can be seen in the politics of paternity testing and the undignified squabble over how many children are really sired by someone other than dad.
Sensitivities over paternity have shaped religious practices, laws, customs for the inheritance of wealth, and behavioural norms.
In their pop bestseller Sex at Dawn, Christopher Ryan and Cacilda Jethá argued that sexual jealousy and paternity insecurity are newcomers to human society, almost unknown in our species' long hunting and gathering past where love flowed more freely and couples stayed together only briefly. The economic changes wrought by farming tied families to the land, necessitating cultural innovations to ensure wealth and land stayed within the family.
Ryan and Jethá make several mistakes, including unduly romanticising our hunter-gatherer ancestors, and viewing culture as something separate from biology. The cultural practices that surround fidelity and conception are more usefully viewed as extensions of men's evolved paternity insecurity. And the scale of those extensions varies among places and over time.
When to worry about promiscuity
When women depend economically on their husbands or partners, then both women and men should value paternity certainty more highly. Men working hard to raise a family have plenty to lose in evolutionary terms if the children they raise are actually sired by somebody else. When men don't do much for their partners or the offspring, they should be much more chilled about paternity, and thus much more relaxed about sexual promiscuity.
Likewise, when a woman depends heavily on a man's labour, or the money he brings in to the household, then the cost of losing him is much greater. There are two ways she might lose him through extra-pair sex: if he has other sexual relationships he could run off with one of the other women, leaving his existing family in the lurch. But when she has extra-pair sex and gets busted, she might lose him. Or worse. Jealousy can trigger psychological abuse and violence.
In the recent paper that inspired this column, psychologists Michael E. Price, Nicholas Pound and Isabel M. Scott, from Brunel University in the UK, sought to test the links between women's economic dependence and both women's and men's attitudes to promiscuity.
From online surveys of more than 5000 Americans, Price and his colleagues showed that when the women in a subject's social network depend economically on men, then subjects tend to judge promiscuity more harshly. And the effects weren't spurious consequences of religion, or ethnicity or political conservatism. When they fitted these other variables into their statistical tests, the association between female economic dependence and opposition to promiscuity remained.
Price also asked whether the association arose as an artifact of geography: Texas and Utah, for example differ culturally on questions of morality and gender roles from, say, Massachusetts or California. States in which women earned more were also more relaxed about promiscuity. And this result arose out of the effects women's earnings had on female economic independence.
Even more compelling, by comparing the attitudes of geographic neighbours, in the same or nearby zip codes, Price and his colleagues found that the association held. Irrespective of where you live, the economic dependence of the women a person's social network predicts how they feel about promiscuity and non-marital sex.
We've known for some time that variation among societies in sexual morality is associated with variation in gender roles and, especially, earnings. The exciting development is how the new research suggests the patterns emerge from the bottom upward, with individual attitudes being shaped by prevailing economic circumstances in their close social network. At least in part.
I'm interested to know what the authors think about the relevance of their data to Roy Baumeister and Kathleen Vohs' ideas on sexual economics in which women restrict the supply of sex under circumstances when they have the most to gain from a high price. This interpretation is not inconsistent with Price et al's arguments about paternity certainty. But high female economic dependence presents exactly the kind of economic situation in which women need to drive a hard bargain in the sexual marketplace. Intriguingly, women took stronger anti-promiscuity stances, on average, than men did.
There are so many studies I would like to see done with a view to teasing out the causal relationships, and how attitudes to promiscuity change in the headwind of religion and other cultural forces. But this finding explains much about some of the trickiest ideological differences both within and among societies.
It could explain how economic changes since the Second World War paved the way for the sexual revolution. And why conservative politicians, especially in the USA seem equally hung-up on sexual liberty and the growing proportion of breadwinner moms.
And it may form an important ingredient in the ever-growing and dangerous ideological chasm between patriarchal theocracies and more gender-egalitarian democracies.
PS I always relish seeing how other media cover research concerning issues touching sexual morality. According to "News Staff" at Science2.0, "If women want their promiscuity to be accepted they have to earn more money say evolutionary psychologists". Keith Perry of the Telegraph reckons "Promiscuous women more likely to be tolerated if they are high earners". And Lydia Smith, writing in the International Business Times got even more pithy, declaring "Only poor women are branded sluts".
These were the first three links to news stories that popped up on Google. Not one headline reflects the real message of the study, but they all find a short path to slut shaming. For the record, the study tracked attitudes to women's and men's promiscuity.
Explore further: Women reject promiscuous female peers as friends, study finds