Why humans are so superior in intelligence? Harari’s hypothesis
Prof. Dr. Abdul Haque
It is a well known fact that humans are so much superior in intelligence as compared to other living beings.
Among the primates, the nearest rival is chimpanzee which has a score of 2.5 as compared to human score of 7.5. so there is absolutely no comparison.
A scientist Yuval Noah Harari presented a hypothesis in 2011 in his book “Sapiens, a brief history of humankind” that there may have been a fast track event which gave modern humans (Homo sapiens) such a clear advantage.
This event is commonly known as “The Tree of Knowledge” because it’s believed to be the source of the vast accumulation of knowledge and understanding that characterizes humanity.
The term “tree of knowledge mutation” refers to hypothetical genetic mutations that altered the wiring of the human brain, enabling new ways of thinking and communicating in early Homo sapiens around 70,000 to 30,000 years ago.
It is believed to have enhanced the mental processes involved in gaining knowledge and comprehension (cognitive power). It is called a “cognitive revolution” which allowed humans to develop complex social structures, create art, imagine things never seen, and believe in shared fictions like money, and nations.
It was not just a matter of growing bigger brains but it also resulted in altering the connectivity of neurons, the nerve cells.
That genetic change was thus probably affecting synaptic plasticity (modifications in connections among neurons) of the brain, supercharging our ability to learn and build complex mental models of the world.
And suddenly, as opposed to merely surviving, our ancestors could create art, develop a complex language, and imagine things never seen.
That single genetic change though, created the difference between us and all the other species on Earth, and made the difference that eventually catapulted us to become the dominant Earthling.
According to this hypothesis there was not just one mutation. There were a bunch of genetic changes involved over a long time.
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Historical evidence tells us that we, the Homo sapiens had already populated East Africa 150,000 years ago. According to this hypothesis of Harari, after this “cognitive revolution”, the Homo sapiens began to overrun the rest of planet Earth and drove the other Homo species to extinction in a short time.
Homo sapiens Homo neanderthalensis
Before this supposed “cognitive revolution” although Homo sapiens looked just like us and their brains were as big as ours, they did not enjoy any marked advantage over other human species, did not produce particularly sophisticated tools, and did not accomplish any other special feats. In fact, they were dominated by Neanderthals. They looked like us, but their cognitive abilities – learning, remembering, communicating – were far more limited.
There is historical evidence that about 70,000 years ago, Homo sapiens started doing very special things. They left Africa for a second time and drove the Neanderthals and all other human species not only from the Middle East, but from the face of the earth.
Within a remarkably short period, they reached Europe and East Asia. And about 45,000 years ago, they somehow crossed the open sea and landed in Australia.
The period from about 70,000 to 30,000 years ago witnessed the invention of boats, oil lamps, bows and arrows and needles (essential for sewing warm clothing). The first objects that can reliably be called art date from this era is a Stadel lion-man.
It is made of ivory and is dated as 32,000 years old. It was found in the Stadel Cave in Germany (c.32,000 years ago). The body is human, but the head is leonine (lion like). This is one of the first indisputable examples of art, and of the ability of the human mind to imagine things that do not really exist.
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This hypothesis by Harari is fascinating but it can never be proved or denied conclusively because of lack of enough scientific evidence. Findings like the Stadel Cave statue are extremely rare.
But if we accept this hypothesis following questions arise:
What was the cause of “Cognitive Revolution”?
Was it accidental?
Why it happened only in Homo sapiens and not Neanderthals (Homo neanderthalensis) or any other Homo species?
From an Islamic point of view, we can say that it was not accidental, it was a design of the creator (Allah) to provide a clear advantage to His deputy (humans) on this earth.