Eve: How the Female Body Drove 200 Million Years of Human Evolution

by Cat Bohannon

In all of our closest primate cousins—chimps, bonobos, and even orangutans—promiscuity has a clear purpose for the female. She’s not just getting her rocks off. She’s making sure that no local male knows who the father is. In biology, this is called “paternal uncertainty.”

That means cooperative culture had to come before monogamy started.

You had to have other cultural checks in place before measures to create paternal certainty made sense.

You had to have bands of ancient hominins who were interdependent and had created clear and dire consequences for any ...

Being in a matriarchal primate society is a bit like spending your entire life in a high school where the popular girls rule. It’s Mean Girls.

In species like ours, males usually have to compete for rank. That’s true in every single social primate species—except our own.

Among our primate cousins, you can be born a princess but never a prince.

Once our ancestors had princes, dominant males gained much more power. The ability to inherit social status bred tighter male coalitions.

Again, in this scenario, it doesn’t happen all at once, but more like a slow tide: Males get more power. Brotherhood gets stronger. Groups of males start coming together to resist the Mean Girls.

When men step out of line, women get mad. When women step out of line, other women get furious.

I propose that women are sexist because we essentially evolved to be.

No—sexism is one of the ways our ancestors solved our hardest problem, which, as I’ve already discussed at great length, is that we categorically suck at making babies.

I think of sexism and gynecology as two sides of the same coin: they’re two behavioral strategies our species employed—and still employs—to try to jury-rig a glitchy system. If pregnancies are dangerous and babies are needy, you need work-arounds.

That’s the core of what sexism is: a massive set of rules that work to control reproduction.

built up over more than a hundred thousand generations.

But men’s bodies were already shrinking by the time Lucy came along. That probably means violent male competition was waning.

So maybe by Lucy’s time, we were already starting to move away from promiscuous matriarchies toward monogamy.

Eventually, we built patriarchies. And there’s a good chance sexism was built into those ...

What we call culture is an emergent property of a huge, complex system: individuals making decisions, most often unconsciously, that collectively and over many thousands of years become ingrained in local identity.

Our ancestors’ birth control was only so good. Our midwifery could save only so many lives. Our abortions used to be really dangerous.[*30] We still needed sexism to get where we needed to go when it came to survival.

Over the millennia, gynecology slowly advanced as cultures constantly tweaked the switchboard to create better reproductive outcomes.

Consistent condom use is remarkably low in places famous for their machismo, from Brazil to Texas, South Korea to South Africa.

The Centers for Disease Control has been tracking them throughout the United States: Minnesota hit a record high for STIs in 2014. Montana more than doubled the rate of gonorrhea transmission from 2013 to 2014.

Louisiana, Mississippi, Georgia, and Texas lead the charge in syphilis, chlamydia, and gonorrhea—all

Syphilis rates tripled between 2012 and 2014 in Louisiana, a state where more than 60 percent of the population regularly attends religious services.

Every year, roughly sixty-two million people are infected with gonorrhea. It’s burning across America like a brush fire, frying the fallopian tubes in its path.

For most of human history, most girls didn’t reach sexual maturity until age 16 or 17.

But if she’s under fifteen, her chances of survival drop drastically. Under thirteen, the chances of survival are even lower.

Maternal age is the single most predictive factor for whether a girl is likely to die simply because she became pregnant.

Reducing the number of girls married before they are eighteen by even 10 percent can reduce a country’s ma...

Thus, the sexist cultures that produce child marriage—places like Niger, Chad, Bangladesh, and Nepal[*41]—are also the ones that kill the most girls, if for no other reason than that they force girls to marry and have sex with older men be...

That such practices are seen as “ancient” is only evidence of humanity’s myopia. Sure, once upon a time, child marriage was also fairly normal in places such as China and Europe, but we’re talking only a few hundred years ago, and since then it’s fallen out of favor.

Ancient Greece aimed closer to sixteen, as did ancient China, while the age of marriage in ancient Rome ranged from fourteen to twenty. What’s more, in Rome the younger brides were often wealthy and married off as a matter of political exchange; the plebes generally married in their late teens or early twenties. The same was true of China and Greece.

In the mammalian game, you can always make more boys. The loss of a healthy, young female is incredibly expensive.

While every pregnancy has risks, pregnancy is statistically more dangerous for obese women than for non-obese women.

but the rise of cheap sugary foods and drinks is strongly tied to the rise in maternal obesity among poorer populations in Europe and the United States.

Where are most pregnant American women dying? Poor communities, yes, but particularly poor communities in Texas, the American South, and Minnesota.

The state of women’s health in these communities, in other words, is starting to look the way it did fifty years ago.

It just so happens that the easiest, cheapest, and most reliable way to increase a community’s wealth is to invest in its women and girls.

In a wide variety of studies, covering cultures ranging from rural America to urban India, women are more likely to allocate financial resources in a way that directly affects the welfare of their immediate households and local community. When given the opportunity, women are more likely to spend a family’s money on food and clothing and health care and children’s education. Men, meanwhile, are more likely to spend it on entertainment

Worldwide, girls and women spend up to 90 percent of their earned income on their families. Men and boys spend only 30–40 percent.

As troubling as it sounds, the data exist: when you leave men in charge, roads and bridges and dams are effectively left to rot.

When women are empowered in local governance, for whatever reason, they are more likely to vote for local infrastructure (and health services and local, directly impactful public spending)

Many well-regarded economists have written extensively about this: give women more money and give them the power to make decisions about where to spend it, and their communities will generally become more economically productive.

For every additional year you educate a girl, her average lifetime wages increase by 18 percent.

For boys, it’s only 14 percent.

The World Bank estimates that for every four years of education, a woman’s fertility is reduced by about one birth per mother.

Let’s put that in the simplest terms possible: four years of school equals one less baby.

This extends to other countries, too: the greater the number of girls who go to secondary school, the higher that country’s per capita income growth.

If you have an IQ even fifteen points higher than the average when you’re eleven years old, you’ll have a 21 percent higher chance of surviving into your seventies.