Have you heard the story about where gossip comes from?
No? Then listen carefully. Because I’m going to tell you something you’ll want to know. But don’t pass it on. You didn’t hear it from me…
Gossiping is a particular and intimate behaviour, which makes working out its origin both difficult and hugely revealing. There are a few competing ideas, and it’s not easy to get to the truth of what drove its evolution, if there was one thing at all.
But the stories about its possible origin are interesting tales to tell, because they are intertwined with our own history: how we learnt to cooperate, how we became ever more social, and the innovative ways we did so.
They bring together grooming, the development of human society and social institutions, and also the way that humans, uniquely, learnt to harness fire.
What is gossip? Put simply, it is a social tool we use to discuss the everyday comings and goings of the people in our lives.
It can be malicious at times but scientists say it can be positive too, a sort of glue that binds society.
As philosopher Julian Baggini puts it, it's a "moral appraisal of other people, it’s about the judgement of what people are doing and whether it’s right or wrong, good or bad".
For gossip to evolve at all, we first needed the basic forms of language. Their origin is also difficult to pin down.
Our common ancestor with apes appeared anywhere between six and 13 million years ago, according some estimates.
To me language is a consequence of these types of social behaviours and that includes gossip.
This ancestor would have been primitive, with a limited brain, meaning it is likely to have communicated using grunts and vocalisations similar to modern chimps.
New research is revealing that ape communication is more sophisticated than first thought. Chimpanzees introduced to a group at Edinburgh zoo, in Scotland, UK, quickly learnt new vocalisations with new meanings; such as "apple", for example.
These vocalisations contain meaningful information, and they offer a glimpse into how human language evolved, says Katie Slocombe from the University of York in the UK.
But they are a long way from qualifying as gossip.
So as well as developing our language skills, our ancestors also had to evolve bigger brains; which ultimately are needed to imagine, process and articulate the information required to discuss the comings and goings of our peers.
An early human species, Homo erectus, lived around 1.8 million years ago. It had much bigger brains than its forebears, and was the first to leave Africa, colonising parts of Europe and Asia. The bigger brains of Homo erectus in turn allowed for the organisation of ever more complex societies. And both further drove the evolution of more complex language.
We can only speculate about the language skills of our human ancestors, as no physical or fossilised evidence can survive to document the spoken word. But gradually as the Homo line continued and became us, language came into being. One version of a gene vital for modern language evolved into its current form about 200,000 years ago, the same time modern humans (Homo sapiens) began to emerge.
But understanding the origin of language doesn’t quite explain the origin of a particular form of it; gossip.
One popular idea, first proposed in the 1990s, is that we need gossip to maintain our social bonds.
Reinforcing and maintaining bonds between individuals is important in many groups of primates, of which humans are also members.
We needed some additional mechanism to allow us to breakthrough what was effectively a glass ceiling
Our closest living relatives, the other great apes, do this mainly by grooming; touching and stroking each other’s hair and bodies, often picking out unwanted parasites or debris.
Human ancestors are likely to have also groomed each other.
Initially grooming served a hygienic purpose. But it "got captured in the course of primate evolution to serve a social purpose", says Robin Dunbar of the University of Oxford, in the UK, who first proposed the hypothesis that gossip also evolved to cement social bonds.
There is evidence for this; cleaning another’s fur only takes minutes, but some primates groom for hours, sometimes up to a fifth of their day. Beyond hygiene, grooming appears to be a way for primates to display their commitment to one another.
So could gossip have emerged out of these more physical origins; a spoken interaction replacing a physical one; both striving to bind together individuals and society?
Perhaps, because there is one advantage to spoken interactions, rather than physical ones. They can scale.
Monkeys and apes can only build relationships with a limited number of associates; as by definition grooming is a one-to-one activity that takes time. This mechanism of bonding "imposes an upper limit on group size", says Dunbar.
"In the course of our human evolution, as we’ve been trying to evolve bigger and bigger groups to cope with the challenges that the world has thrown at us, we needed some additional mechanism to allow us to breakthrough what was effectively a glass ceiling," he adds.
The mechanism may have been the evolution of gossip; harnessing the appearance of language. Gossiping allows individuals to "groom several people simultaneously" and share social information at the same time, says Dunbar.
Since Dunbar proposed his hypothesis, it has been considered the most likely explanation.
But listen to this. There could be more to the story, because early humans required other skills, beyond big brains, language and a need to bond.
To successfully hunt and forage, early humans needed to cooperate. And the most effective way to cooperate is to share information about each individual’s role. Who will chase the prey, and who will catch it, for example. Who looks left for edible plants, and who looks right. To gossip about one another, in other words.
That's what Klaus Zuberbuehler from St Andrews University in the UK, believes. As our early human ancestors moved out of the forest into more open savannahs, there was a greater need to work together to successfully hunt for food. This fostered a high degree of teamwork, and the sharing of personal information.
That drive to share information runs deep and we can see it today in our children. From a very young age, children point out interesting nuggets of their daily lives to friends and family.
It's this type of social, supportive aspect to human nature that allowed gossip to come about, says Zuberbuehler.
"To me language is a consequence of these types of social behaviours and that includes gossip,” he says. “You need to know who is with whom and who is supporting whom. Chimps only have to make sure they stay together and for that they have signals, vocalisations and gestures that help them."
Humans on the other hand, gossip and exchange relevant information all the time.
So for Zuberbuehler, gossip is unlikely to have originated among our primate ancestors as an extension of their need to physically groom one another.
As evidence, he points out that chimpanzees do cooperate with each other, but not how humans do. His studies show that chimps may alert each other to the presence of a dangerous snake, or a source of good-to-eat honey. But such cooperation only serves to meet individual, immediate goals.
However, humans are capable of "joint intentionality". We share information to meet common goals, often far in the future. We plan together, and scheme together.
Gossip then, must have come about as a consequence of our increased understanding of shared needs, Zuberbuehler says.
But like any good story worth sharing, there is one final twist.
That’s because there’s one other heartening idea; that gossip evolved as a consequence of the uniquely human ability to harness fire.
The hypothesis is this. During daylight early humans largely spent their time trying to stay alive; finding food and shelter, while avoiding being eaten themselves by predators. At night they had little choice but to sleep. But the invention of fire, perhaps as early as one million years ago, transformed these hours of darkness.
Warmer, and safer around a campfire, early humans could start to communicate more freely, a form of idle chat, perhaps.
Recent research supports the idea, showing that the conversations of modern hunter-gathers differ during the hours of light and dark. In the day, bushmen in the Kalahari desert in Botswana talk of practical matters. But at night, they speak differently, and storytelling thrives, discovered researchers eavesdropping on their conversations.
A good story is the foundation of a good bit of gossip, especially if those sharing it care about what they are saying.
Camilla Power of the University of East London in the UK studies hunter-gatherer groups today. Around the fire, she says, people could meld story with rituals such as dancing with singing. "These are the things that give us a real emotional connection." And if such talk feels good, there are strong reasons it would continue.
Ancient genetic clues
Determining the exact origin of gossip may prove elusive, due to its ephemeral nature.
We may gain new insights from genetic research into ancient human DNA. If we could pinpoint genes for sociality, it would help us understand whether other early humans, such as Neanderthals, had similar abilities, and how developed was their language.
Scientists have already sequenced the Neanderthal genome and that of their close human relatives, the Denisovans. Indeed Neanderthals are known to have a version of a gene vital for speech that we also possess.
Tecumseh Fitch of the University of Vienna, Austria, is betting on exactly this. He is even hopeful we might one day find Homo erectus DNA. If our early ancestors had the same genetic components for language, they might then, also have gossiped.
But until then, the story of the origin of gossip will remain one to be debated, shared and retold. And like the subject itself, it will stay a combination of hard facts and speculation.
With perhaps just a sprinkling of hearsay thrown in for good measure.
You can listen to Robin Dunbar discussing the origins of gossip on the BBC World Service programme "Hot Gossip".
Follow Melissa Hogenboom and BBC Earth on twitter.