Last week, scientists from University College London released a paper presenting evidence that men and women in early society lived in relative equality. The paper challenges much of our understanding of human history, a fact not lost on the scientists. Mark Dyble, the study’s lead author, stated “sexual equality is one of the important changes that distinguishes humans. It hasn’t really been highlighted before.”

Despite Dyble’s comments, however, this paper isn’t the first foray into the issue. In fact, it represents another shot fired in a debate between scientific and anthropological communities that has been raging for centuries. It’s a debate that asks some fundamental questions: who are we, and how did we become the society we are today?

Our modern picture of prehistoric societies, or what we can call the “standard narrative of prehistory” looks a lot like The Flintstones. The narrative goes that we have always lived in nuclear families. Men have always gone out to work or hunt, while women stayed at home to look after the house and the children. The nuclear family and the patriarchy are as old as society itself.

The narrative is multifaceted, but has strong roots in biological science, which can probably be traced back to Charles Darwin’s theory of sexual selection. Darwin’s premise was that due to their need to carry and nurture a child women have a greater investment in offspring than men. Women are therefore significantly more hesitant to participate in sexual activity, creating conflicting sexual agendas between the two genders.

This creates a rather awkward situation. With women producing such “unusually helpless and dependent offspring”, they require a mate who not only has good genes, but is able to provide goods and services (i.e. shelter, meat and protection) to the woman and her child. However, men are unwilling to provide women with the support they require unless they have certainty the children are theirs — otherwise they are providing support to the genes of another man. In turn men demand fidelity; an assurance their genetic line is being maintained.

Helen Fisher calls this ‘The Sex Contract’, but the authors of Sex at Dawn, Christopher Ryan and Cacilda Jethá, are a little more cutting in their analysis: “the standard narrative of heterosexual interaction boils down to prostitution: a woman exchanges her sexual services for access to resources … Darwin says your mother’s a whore. Simple as that.”

Herein, so some scientists say, lie the roots of our nuclear family and the patriarchy. Our gendered hierarchy is based on an innate biological need for women to be supported by men. The very capacity for women to give birth to children places them in a lower position within society.

Scientists use a whole range of other evidence to support this narrative. Many for example point our closest relatives. Scientists have researched monogamy of gibbons and the sexual hierarchies of chimpanzees to point to a “natural” expression of our innate desires.

Other scientists use human biology. A common example is women’s apparently weak libido. Discussing his book Why Can’t a Woman be More Like a Man? released last year, for example, Lewis Wolpert states: “About half of men think about sex every day or several times a day, which fits with my own experience, while only 20 per cent of women think about sex equally often. Men are far more likely to be sexually promiscuous, a throwback to evolution where procreation was all-important.”

If you subscribe to the theory of a sex contract this is logical. A lower sex drive ensures women are more selective in their sexual decisions, making certain that they only mate with high-quality men. Women, so some scientists say, are evolutionarily designed to be selective in their mates.

Yet, for centuries many have questioned the logic, and the biology, of the standard narrative.

The first real splash in this arena came from the anthropologist Lewis Morgan, and his book Ancient Society. In the book Morgan presented the results of his study of the Iroquois, a Native American hunter-gatherer society in upstate New York. The Iroquois, Morgan observed, lived in large family units based on polyamorous relationships, in which men and women lived in general equality.

Morgan’s work hit a broader audience when it was taken up by Friedrich Engels (most famous for being the co-author of the The Communist Manifesto) in his book The Origin of Family, Private Property and the State. Engels drew on Morgan’s data, as well as evidence from around the world to argue that prehistoric societies lived in what he called “primitive communism”. Other anthropologists now call this “fierce egalitarianism”: societies where families were based on polyamory and in which people lived in active equality (i.e. equality is enforced).

Morgan and Engels were not painting a picture of a “noble savage”. Humans were not egalitarian nor polyamorous because of their social conscience, but because of need. Hunter-gather societies were based largely on small roaming clans where men engaged in hunting, while women’s roles focused around gathering roots, fruit and berries, as well as looking after the “home”. In these societies community was everything. People survived through the support of their clan and therefore sharing and working within their clan was essential. This crossed over into sex as well.

Polyamory helped foster strong networks, where it became everyone’s responsibility to look after children. As Christopher Ryan states: “These overlapping, intersecting sexual relationships strengthened group cohesion and could offer a measure of security in an uncertain world.” The same can be said for our other social hierarchies. As Jared Diamond explains, with no ability or need to store or hoard resources, “there can be no kings, no class of social parasites who grow fat on food seized from others”. Hunting and gathering enforced social equality. It was the only way people could survive.

While initially developed in the 1800s, these theories died down somewhat in the early 20th century. With Engels’ connection to Marx, many of these ideas were lost in the great philosophical debate of the Cold War. Many second wave feminists, led primarily by Simone de Beauvoir in her book The Second Sex, also argued against Engels’ ideas.

Recently however, these theories have had something of a renaissance. On top of Dyble’s study last week, new anthropological and scientific evidence backs up this challenge to the standard narrative. In 2012 Katherine Starkweather and Raymond Hames conducted a survey of examples on ‘non-classical polyandry’, discovering the phenomenon existed in many more societies than previously thought.

In another example Stephen Beckman and Paul Valentine examined the phenomenon of ‘partible paternity’ in tribes in South America: the belief that babies are made up from the culmination of the spermatozoa of multiple males. This belief, which is common in tribes in the Amazon requires polyamorous sexual activity by women, and that men share the load of supporting children.

And then there is the example of the Mosua in China, a society in which people are highly promiscuous and where there is no shame associated with this. Mosua women have a high level of authority, with children being looked after by a child’s mother and her relatives. Fathers have no role in the upbringing of a child — in fact the Mosua have no word to express the concept of “father”.

In Sex at Dawn, released in 2010, Ryan and Jethá provided a range of biological evidence to back up this anthropological data. Let’s take a look at their counteractions to the two examples produced earlier: the behaviour of our closest relatives and women’s apparently low libido.

Ryan and Jethá argue that while yes, gibbons and chimpanzees are close relatives, our closest relatives are in fact bonobos. Bonobos live in female-centered societies, where war is rare and sex serves an important social function. They are polyamorous, with both male and female apes having regular sex with multiple partners. This looks more like the societies Morgan and Engels were describing.

When it comes to women’s “low libido”, Ryan and Jethá simply disagree, arguing in fact that women have evolved for sex with multiple partners. They look, for example, at women’s ability to have multiple orgasms in a sexual session, to have sex at any time during their menstrual cycle and their propensity to make a lot of noise during sex — which they argue is a prehistoric mating call to encourage more men to come and join in. These evolutionary traits have occurred, they argue, to ensure breeding is successful.

In short, Dyble’s paper is unlikely to provide the conclusion to a battle that has been raging for at least two centuries.

The paper, however, certainly is another nail in the coffin of the standard narrative of prehistory. One this seems clear: our history is much more complex than previously thought. How complex, we may never know. Without a time machine it is impossible to confirm. But we now can be certain that things in the past were very different to the standard narrative. We are not all just versions of the modern stone age family.