by Bjørn Grinde
Although rational in many ways, the idea of considering human beings as something apart from nature is dangerous. Evolution has shaped all organisms, us included. Moreover, we are all shaped to live in particular environments. If animals are kept under unfavourable conditions their health tends to deteriorate, they typically behave oddly and appear discontent. People living in modern societies show similar ailments, as witnessed by the incidence of various maladies, including mental disorders. I believe it is possible to alleviate these problems by creating living conditions closer to those our genes are adapted to; but in order to do so, we need to accept our biological inheritance.
Our ancestors once lived in the forest. I imagine a soft and green Garden of Eden. A long time ago they were animals like all the rest, but our more recent ancestors decided to be something else – something apart from nature. What happened? Why did we choose a different path; and more important, where does this path take us?
The crucial step seems to have been the invention of agriculture approximately ten thousand years ago. It was a bizarre move, because we are pretty sure that the gardens of the early settlers were no more pleasant than the Garden of Eden they left behind. Farming did not free us from a life of toil. People apparently spent more time procuring food by cultivating the land and caring for animals than they had done as hunters and gatherers. Thus, most likely they chose this path out of necessity, not out of indolence: The climate was drying up, and the population was growing beyond the land's carrying capacity; people therefore needed to obtain more food per acre of land. As farmers, so they did.
In biology, success is measured in terms of number of offspring, or as the total 'biomass' of the species. According to these terms agriculture was a great success. It allowed for the creation of societies larger and more powerful than tribes, and it gave us a culture with specialists to cater to different tasks. All in all it was a revolution. What happened has parallels to one of the most significant episodes in the history of life: the invention of multicellular organisms a billion years earlier. Both events led to the creation of specialists working together – and both events changed the face of the Earth.
Life with only single-celled organisms can hardly be more than muddy water. But life with agriculture, and all the innovations that followed, may, in a worst-case scenario, eventually reduce life to about the same.
Unfortunately our brains never adapted to all the opportunities of the modern world. When stimuli beckon, the reward mechanisms laid down in my nerve circuitry whisper: Go for it! Which is why I prefer wine instead of water, and the flickering of a TV screen, rather than a story told by a friend. And which is why I prefer the superstimuli of a metropolis.
In the oldest known city, Catalhöyük in Turkey, the houses were built so close to each other that the entrances had to be through the roofs. The first Big Apple. Since then we have been lured by the notion that the place to be is where most people are gathered.
Our genes are basically the same now, as they were a hundred thousand years ago, as evidenced from the accepted theory that the more distant surviving twigs of our family tree branched off at about that time. Thus, however much concrete or how many people I am surrounded by, in my heart and in my brain I am still a Stone Age person. And as such, I do not need a crowd – I should be with my tribe. But in today's world, the crowd is all I have.
Yes, our genes are adapted to a Stone Age way of life. They expect our bodies, including our brains, to mature in interaction with the social, physical and natural environment of those days. When conditions deviate from that norm, we gamble with our health. Some changes may not matter, or may even be purely beneficial, but other discrepancies make us vulnerable.
Unfortunately it is difficult to tell which changes are good and which are bad. Take our immune system, for example. A highly complex entity designed to interact with the surrounding world of germs, our immune system seems to suffer from a lack of dirt! Ten thousand years ago babies crawled on a carpet of soil and grass. Today, in the absence of a steady stream of mostly innocent bacteria to contend with, the immune system tends to develop aberrant 'behaviour'. It launches excessive attacks on harmless pollen or, even worse, on the person it belongs to. Asthma, allergy and rheumatic disorders descend on us like plagues. But who would have guessed that the solution may be a bit of Stone Age living: a daily spoonful of mud for the babies?
How about our brains? The brain is not only the most complex, and least understood, part of us; it is also a part that requires extensive interactions with a suitable milieu in order to mature properly. As a consequence, the brain is probably our most vulnerable organ when it comes to misdirected development due to suboptimal conditions.
According to the National Institute of Mental Health, an estimated 22 percent of adult Americans suffer from diagnosable mental disorders in a given year, the more common problems being related to depression and anxiety. And the more overt forms of psychiatric disorder are presumably just the tip of the iceberg of mental agony and suboptimal quality of life.
Should we be surprised?
The Masai people of the Great Rift Valley appear to be content. They are a part of nature and they take part in nature. The children play in the shadow of the trees, and develop relationships lasting a life-time. Maybe more important: The Masai do not have separate cribs or separate rooms in which to store their children; and the babies are carried close to the bodies, typically skin against skin. It has been shown that the simple touch of another person is enough to give a surge of endorphins, the brain's natural opioid drug of choice. The lack of dirt has been proposed to foster the baby with a propensity for allergy. Perhaps the lack of parental proximity and the suboptimal dose of intimacy cause a propensity for anxiety and depressions.
There are many discords between the nature of being human and the human-made 'nature' we presently live in. Most discords are not life threatening. We survive and breed in the city. True, many of us even thrive in a ghetto of concrete, but, as indicated by the statistics of mental health, for the average person life could be better. Something seems to be wrong, and I believe the medicine we ought to prescribe is to heed the calling of our genes.
Deep inside we yearn for the Garden of Eden, for a life in tune with our genes: a life in the tribe and close to nature. But we may not be aware of the gloom taking root in its absence, like we never sensed the allergy coming.
So, the big question is: When we invented the plough, did we take a step towards – or away from – paradise?
As a member of the most successful animal ever to have walked on Earth – in terms of biomass – I look back at ten thousand years of accelerating progress, and I am still not certain which way we are heading. Obviously, we have gained a lot, but overall, are we better off? We talk about the 'diseases of civilisation', is life in the Big Apple really that much better than life in the Stone Age Eden? Research has shown that rich people are not much happier than poor people. As long as the basic needs were cared for, our ancestors, like the Masai, were probably content. What more can anyone ask for?
Sometimes it appears to me that we used the plough to turn the Garden of Eden upside down.
Evolution gave us this measure of free will. As a consequence of that, humans have evolved a capacity for enjoyment that probably is unequalled by any other organism: In the absence of instincts to drive our behaviour in genetically sensible ways, evolution installed rewarding and punishing sensations to guide us. Thus your brain can bless you with a flood of rewards, but, incidentally, also drown you in pain. The brain can truly do wonders for you, but when it goes awry, due to too many discords, it can also turn into your worst enemy.
Few of us would want to sacrifice all the advantages of modern living, but, fortunately, that may not be necessary. Many of the discords between genes and environment can be dealt with within the frame of a modern society. But in order to succeed, we need to understand our own nature. Yes, we do tend to choose whatever kindles the reward circuitry of the brain, even when these choices obviously do not benefit us, as when taking drugs; but it is also within our power to make rational choices. Evolution gave us this extraordinary intellect, and the measure of free will to accompany it. By using these unique human capacities, we can resist temptations offering short-term benefits, and we can create a paradise superior to anything we ever had. We can make a new Garden of Eden.
Bjørn Grinde is chief scientist at the Norwegian Institute of Public Health. He works (among other things) on how our current understanding of our evolutionary background can help us design a better place to live.Copyright by Bjørn Grinde, 2004. All rights reserved
http://www6.sunydutchess.edu/bhs/andrews/garden_of_eden1.htm
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