What is the secret of our success?

The miracle in the Colombian jungle is a testimony to our species

It is an extraordinary story of human endurance and survival, all the more remarkable for the ages of the people involved. Four children, including a 12-month-old baby, were found alive in the remote Colombian jungle after making it out of a plane crash which killed their mother. They had survived for six weeks before being found by the military.

The eldest, a 13-year-old girl called Lesly, kept her siblings alive, using ‘her deep knowledge of the jungle, and what could be retrieved from their family’s luggage, as survival tools. Rescuers said they had found traces of ribbons and a pair of scissors which had been used to build a tiny roof to protect their temporary encampment from the intense rain.’

As the Times reported: ‘Among the dangers the children could have faced in the jungle, as well as poisonous insects, were alligators, jaguars, and anacondas. On Friday the four were lifted out to safety via a 60-metre cable suspended from a military helicopter. They were immediately taken to hospital where their condition last night was described as stable. All are expected to make full recoveries.’

Although the grandmother explained that her eldest had from an early age shown a great caring instinct, perhaps most importantly ‘the four were members of the Huitoto indigenous community, who grew up in a jungle environment.’

‘Their learning from indigenous families and their learning of living in the jungle has saved them,’ Colombia’s president said: ‘They are children of the jungle, and now they are also children of Colombia.’

Almost none of us would have survived the jungle, perhaps even those with military training. Indeed, you could send the most resourceful and intelligent people into such a hostile environment, and most would die, because human beings are extremely reliant on culturally-inherited knowledge — in many cases, what their grandparents teach them is the most important thing they’ll learn.

This is the premise of Joseph Henrich’s The Secret of our Success, which looked at the role of cultural evolution in human evolution. Henrich’s theme is that, not only are humans physically weak, but we are not that intelligent as individuals; our strength and power comes from our ability to tap into culturally-acquired knowledge, a process that begun several million years ago and has had a big influence on our evolution.

As Henrich wrote, humans have managed to colonise the most inhospitable environments: ‘Yet, puzzlingly, our kind are physically weak, slow, and not particularly good at climbing trees. Any adult chimp can readily overpower us, and any big cat can easily run us down, though we are oddly good at long-distance running and fast, accurate throwing. Our guts are particularly poor at detoxifying poisonous plants, yet most of us cannot readily distinguish the poisonous ones from the edible ones. We are dependent on eating cooked food, though we don’t innately know how to make fire or cook. Compared to other mammals of our size and diet, our colons are too short, stomachs too small, and teeth too petite. 

‘Our infants are born fat and dangerously premature, with skulls that have not yet fused. Unlike other apes, females of our kind remain continuously sexually receptive throughout their monthly cycle and cease reproduction (menopause) long before they die. Perhaps most surprising of all is that despite our oversized brains, our kind are not that bright, at least not innately smart enough to explain the immense success of our species.’

Humans survive because of culture, ‘the large body of practices, techniques, heuristics, tools, motivations, values, and beliefs that we all acquire while growing up, mostly by learning from other people.’ From a million years ago, ‘members of our evolutionary lineage began learning from each other in such a way that culture became cumulative. That is, hunting practices, tool-making skills, tracking know-how, and edible-plant knowledge began to improve and aggregate—by learning from others—so that one generation could build on and hone the skills and know-how gleaned from the previous generation.’