CARNAL KNOWLEDGE: HOW BETTER DATA COULD LEAD TO BETTER SEX / THE ECONOMIST

Carnal knowledge

How better data could lead to better sex

What we don’t know about human sexual behaviour is scandalous

Years ago, when Caroline Kabiru was due to learn about sex in school, she found that the relevant pages of one of the textbooks had been glued together. 

And the teacher never showed up.

Oddly, given how much time people spend thinking about sex, many understand it only poorly. 

Dr Kabiru, who is now an expert at the African Population and Health Research Centre in Nairobi, recalls a survey her team conducted among young Kenyans in 2008. 

Roughly half thought the time of the month when a woman was most likely to get pregnant was during her period. 

She speculates that this myth may have arisen because when a girl gets her first period, many Kenyan parents say “Now you must stop playing with boys, or you might get pregnant.”

Globally, three forces hinder the spread of good information about sex. 

One is shame—many adults, like Dr Kabiru’s biology teacher, find the topic embarrassing. 

Another problem is that bad information often crowds out the good. 

Many teenagers pick up ideas from online pornography, which is as accurate a guide to real sex as James Bond films are to the daily routine of a British civil servant. 

Rebecca Cant of Brook, a British sex-education charity, quotes one teenage boy who said, in all seriousness, that he was not ready to have sex with his girlfriend because he was “not ready” to choke her. 

He assumed it was expected.

A third problem is that data are often not gathered in the first place. 

Lianne Gonsalves of the World Health Organisation (WHO) cites three blind spots: non-wealthy countries, men and people over 50. 

Less is known about poor countries than rich ones, since they have less money for sex surveys. 

(China and Russia are black holes, too.) And less is known about men and older people because most big surveys concentrate on those who might get pregnant.

These are huge omissions. 

To make things harder, some governments are prudish, and so reluctant to pry into this area. 

Some people, when asked about their sexual habits, do not tell the truth. 

And in several countries gay sex is still illegal, making it tricky even to pose questions about it.

Early sex research was often shoddy. 

In 1948 Alfred Kinsey’s “Sexual Behaviour in the Human Male” scandalised America, but since it was based on non-random samples it was wildly inaccurate.

Globally, aids gave a big boost in the 1980s and 90s to better research. Britain’s well-regarded national sex survey, natsal, wouldn’t have happened without it, reckons Soazig Clifton of University College London. 

Scientists and rational politicians immediately saw the point of studies to help predict the spread of what was then an invariably fatal disease.

Let’s talk about sex, baby

The broadest source of reliable data today, the usaid-sponsored Demographic and Health Surveys (dhs), are conducted in 90 countries and focus on females aged 15-49. 

They tend to ask basic questions about acts that might lead to infection or conception (“bugs and babies”). 

They don’t ask about pleasure, consent or the context in which sex occurs.

Understanding sex is not just a matter of public health. 

Evidence from America, India and other places suggests that troubles with emotional or physical intimacy are a cause of 20-50% of divorces—which tend to make children sadder and families poorer. 

If better information leads to better sex, it could add to the sum of human joy for a trivial price tag. 

Small wonder sex researchers are passionate about their vocation.

To start, some are trying to extrapolate more information from basic surveys. 

Emma Slaymaker of the London School of Hygiene and Tropical Medicine and her co-authors crunched data from DHS surveys and estimated the number of partners people in 47 developing countries could expect to have by the age of 50.

There was enormous variation. 

A Congolese man of 50 will have had on average 20 partners; an Indian, only nine. 

There was great variety within continents, too. 

Men from Niger have only an eighth as many as their Congolese peers. 

Is this because they often live in small, conservative villages and must cross large deserts to find cities with nightlife? 

No one knows.

Everywhere, women report fewer partners than men. 

This may sound mathematically improbable, but surveys seldom capture sex workers and women often underreport. 

Their stated lifetime tally ranges from 1.2 in Cambodia to nine in Gabon; for men it ranges from 2.4 in Niger to 21 in Gabon. 

Several countries fit the stereotype that as men get richer, they have more partners. 

But in India and Madagascar, it is the other way round: poorer men have more partners. 

Perhaps this is because many migrate to work far from their families and pay for sex; again, it is hard to be sure.

The chance of having more than one partner at the same time varies, too. 

Men in Niger who already live with a partner are 60% as likely to find a new one each year as their single compatriots; for men in Albania, the figure is only 1%. 

This may reflect widespread polygamy in Niger—and perhaps a reluctance among Albanians to admit to pollsters that they are cheating.

As people live longer nearly everywhere, they are not giving up on sex. 

Being over 55 need not mean “focusing only on gardening and trying to get your socks on without putting your back out”, notes David Spiegelhalter, a statistician and author of “Sex by Numbers”. 

Libido declines with age, but slowly, and older people are more likely than in previous generations to be divorced and seeking new partners. 

Yet in most countries no one has much idea what they get up to. 

Data that do exist suggest big differences. 

The median 55- to 64-year-old British woman with a partner has had sex twice in the past month; her 49-year-old married Japanese peer has done it zero times. Why?

“Maybe it’s norms,” suggests Peter Ueda of the Karolinska Institute in Stockholm. 

In western Europe, a sexless marriage might be seen as a sign that the relationship is in trouble. 

In Japan “It’s sort of accepted, [since] marriage is more transactional.” 

It cannot help, though, that more than 70% of Japanese married women over 50 say they and their husbands “never communicate” about their sexual desires.

A study in South Africa, by contrast, found that the old were strikingly vigorous: most men were still having sex until their 80s. 

It also noted that 23% of men over 40 had hiv, and few used condoms. 

Despite this, information about hiv risks among older adults is scarce, the authors lament, and “very few prevention interventions [are] specifically targeted” at them.

Poor information is not only a problem for societies, but also for couples. 

Many are reluctant to talk about sex, which can make it not just unpleasurable but unpleasant, especially for women. 

Even when men are well-meaning, they are seldom telepathic. 

They cannot simply guess what their partners like or dislike, and non-verbal cues are no substitute for frank talk. 

This is tricky, though, when the topic is shrouded in shame. 

Consider Bangladesh, a conservative Muslim country. 

Its dhs survey collects data about marriage and contraception, but not about pleasure or consent. 

How satisfied are Bangladeshi women with their sex lives? 

How easy is it for them to tell their husbands what they want? 

Anecdotally, not easy at all.

“Sexual dissatisfaction is really high with women in Bangladesh,” says a local feminist who prefers not to be named. 

“Lots of women have heard of this thing called an orgasm, but they’ve never had one. 

If I told my husband, ‘you do this and I don’t enjoy it, he would be so upset he would not be able to perform again.’”

If a wife asks for something new, her husband may angrily assume she is promiscuous, suggests Prima Alam, a sexual-health researcher: how else would she know of such things? 

No one is taught to think about women’s pleasure, she laments. 

If they have watched porn, “what they see is [the man] just doing it, and the woman apparently enjoying it, screaming and so on, but real life is not like that, right?” 

The local mindset is that men should take charge. 

“I think marital rape may be common, but we don’t have enough data.”

What would it take to boost sex research? 

Perhaps voters’ hunger for information will gradually outweigh politicians’ squeamishness. 

Nana Darkoa Sekyiamah, author of “The Sex Lives of African Women”, and co-founder of a blog, “Adventures from the Bedrooms of African Women”, reckons there is plenty of bottled-up demand for more information. 

She hears “a lot more conversation about oral sex”, suggesting that “Younger men have realised that for most women, the standard penis-in-vagina sex is not [good enough].”

Britain could provide an example. 

Sex education in British schools is fact-based. 

Teenagers who rely on it are less likely to have their first sex while under the age of 16, and their first experience is more likely to be a good one, with both partners willing and protected. 

The country has problems aplenty in the bedroom, NATSAL reveals, but only around one in seven sexually active Brits says they are sexually dissatisfied. 

Those who feel at ease talking about sex with their mates are more likely to enjoy it, notes Ms Clifton. 

And young Brits appear to be communicative: happy to try something new, but ready to stop if their lovers don’t like it.

Oral sex, which was once so taboo that prostitutes charged more for it than penetrative sex, has become a staple, especially among the better-off and the young. 

When it comes to anal sex, by contrast, around 50% of British men and 40% of women aged 25 to 34 in 2010 had tried it, but fewer than half as many had done it in the previous year. 

Dr Spiegelhalter suggests that for many it is “tried for the experience but [does] not necessarily become a habit. Like swimming at Blackpool.”

With more accurate research that was more widely disseminated, people would have a better sense of what others get up to. 

That might make it easier to overcome taboos, which are often based on circular reasoning (you shouldn’t do x because it is “not normal”). 

“Knowing you’re not alone is really helpful,” says Ms Darkoa Sekyiamah. 

“If you know that lots of other couples have oral sex, [for example], that quite often will make people feel that it’s okay and it’s something that they might try.” 

A culture of transparency around what other people do might also help couples talk to each other about what they actually want.

Experts at the who are eager to fill some of the gaps in the world’s knowledge. 

They have spent four years devising a much more detailed survey called shape. 

It asks, for example, about degrees of consent. 

(The last time you had sex, did you want it, just go along with it, or were you “forced or frightened” into doing it?) 

The aim is to do shape surveys all around the world. 

But so far, funding has not materialised. 

For most governments, it is not a priority.

And many conservatives are loth to fund research that might reveal unwelcome facts, such as that some of their compatriots are gay. 

Some go further. 

In 2024 Ghana’s parliament passed a bill, which awaits the president’s signature, to ban any “promotion” on social media of “unnatural” sex. 

This would make Ms Darkoa Sekyiamah’s broad-minded blog illegal.

She recalls that she married the first man she had sex with, “Because I felt that’s what you had to do.” 

It was only after her divorce that she came into her own, sexually. 

Now in her 40s, she says she wouldn’t want her daughter, or any other young girl, to make the same mistakes she did. 

And to avoid that, they need to hear straightforward talk about sex.