What does it mean to be human? We’ve pondered over this puzzle for centuries. From philosophy, to evolutionary biology, to neuroscience, there are many different ways to approach the question, but one suggestion seems to come up time and time again: intelligence.
Human beings have proven themselves smart enough to build entire civilizations, to travel the universe, to learn the dance moves to the Macarena. We’re capable of many things. And so it’s fair to deduce that our intelligence must be a uniquely human trait. But what if it isn’t?
The great apes are our closest living relatives, and when we look closely at their behaviour, there is something undeniably ‘human’ about them. But we now have reason to think that chimps and some species of monkeys may be even smarter than we previously gave them credit for.
A New Age
Evidence is growing to suggest that chimpanzees and monkeys have entered the Stone Age: a period of prehistoric culture characterised by the use of stone tools. And what’s more, this form of behaviour may have been going on a long time – potentially thousands of years.
Observed cases of monkeys and chimps using stone tools have cropped up in Asia, Africa and South America, and it’s thought that different communities and species may have independently evolved the use of tools over generations.
In a landmark 2007 study, chimpanzees on the Ivory Coast were found to have been using stone tools for at least 4,300 years. That means that back when human beings were still in the Bronze Age, chimpanzees were already experiencing their own unique Age.
So how exactly do we know what these creatures were up to all those years ago? Well, the burgeoning field of primate archaeology can tell us a great deal about long-term behavioural history.
In a 2016 study from Oxford University, researchers demonstrated that Brazilian capuchin monkeys have been exploiting stone tools to access food for at least 700 years. These little creatures – colloquially known as ‘organ grinder’ monkeys – use stones to crack open stubborn cashew nuts. And it looks like they’ve been doing this since the Renaissance period – years before Europeans set foot in the new world.
The Oxford group demonstrated this amazing find by excavating the area around the capuchin’s ‘workshop’ to uncover ancient tools. They found a total of 69 stones which displayed signs of capuchin usage, and used carbon dating to determine the stones’ age.
Their findings suggest that approximately 100 generations of capuchins have used stone tools. The study even poses the question: did human arrivals to the new world learn techniques for opening cashew nuts from observing the native monkeys?
Of course, none of this is to say that we can expect a Planet Of The Apes scenario any time soon. Another recent Oxford study observed that whilst the monkey’s rock banging creates stone flakes that could be used as knives, they do so unintentionally, without any realisation of the flakes’ potential. These animals are certainly clever, but they’re not quite there yet.
But all of this aside, perhaps one of the most intriguing elements of the newly-discovered chimp and monkey Stone Age is what it can tell us about our own history.
Our view of how humans have evolved – how we made the leaps to tools, to fire, to civilization – is being shaped and redefined as we learn more about the behaviour of our primate relatives. This, in turn, prompts questions about the uniqueness of our story, and fuels the fires of that enduring question: what does it mean to be human?
A version of this article was originally published in The Oxford Mail