Cultural creatures

Adam Zeman uncovers the biology behind our human capacity for creativity and cultural change.

We are the most restless creatures. ‘Change, change, change – aren’t things bad enough already?’ exclaimed Lord Palmerston, but his implied advice is seldom heeded. Cultural change is constant and relentless: speech, dress, music, dance, décor, cookery, literature, medicine, science, indeed all conceivable human activities are in a permanent state of flux – hence the belief of the middle-aged that the world is in terminal decline, matched by the belief of the young that their parents have completely lost the plot. Can science shed any light on the – invigorating or exasperating – human propensity to innovate?
  
At first glance, the answer is: plainly not. Cultural change is in the realm of history, not science. Understanding why we prefer our jeans slung low, our boxers high, or why it’s cool to club or best to use a rounded spoon for soup calls on the skills of the cultural historian – not the biologist. And, of course, it is perfectly true that there is an historical story to tell about these preferences – but it is a serious mistake to draw too sharp a line of demarcation between human biology and human culture. Why?

Our hominid line diverged from the lineage that gave rise to the gorilla and the chimp roughly five million years ago. For at least half that time, our ancestors were creating forms of early human culture. Homo habilis, known from fossils in Ethiopia, Zaire, Kenya and Malawi, shaped the earliest known stone tools around 2–2.6 million years ago. The brains of these early toolmakers were larger than those of the first hominids, the Australopithecines, but still only about half the size of the brain that you are using to read this article. What lies between those early hominid brains and yours or mine is a history of extraordinary creativity and innovation. This has a crucial implication: the emergence of human culture – the production of increasingly sophisticated tools,  taming fire, building shelters, the use of burial, the beginnings of art, the creation of language – went hand in hand with the remarkably rapid evolution of the brain. It is very likely that each fuelled the other in the struggle for survival, as the refinement of the cultural traditions made possible by our enlarging brains increased the evolutionary pressure to hone the intelligence with which to develop them further. Culture, if so, is an integral – and central – aspect of our biology: we are precisely cultural animals.

If this is right, what is the biological recipe for culture of a human kind? It has social, psychological and neural elements. First, on the social plane, rather self-evidently, culture requires community: it is the product of the collective, not of an individual. Two features of human communities, each partly the product of culture, play an especially crucial role in its creation. Language, which is equally a social and a biological phenomenon, has many uses besides information exchange, but it undoubtedly enables us to share cultural innovations with extreme rapidity and efficiency. Division of labour allows cultural developments to proliferate as specialists such as farmers or hunters, shamans or poets become expert in their trades and simultaneously extend the boundaries of invention. But while culture is the product of the community, its achievements depend on the capacities of individuals – so what particular aspects of the human psyche, and the brain that sustains it, make us naturally cultural creatures?

Cultural creaturesCreatures who live by their wits, as we do, must be capable learners – rather than rely on instinct we must acquire our skills for living. Our brains equip us for this task by providing us with the most capacious information store in the known universe. The human brain contains somewhere around 100,000 million nerve cells or neurons, each of which has on average perhaps a thousand connections with other cells. These connections, synapses, are thought to provide the foundation for memory: experience sculpts the interconnection between neurons, strengthening or weakening them, causing them to contract or to proliferate, building transient or permanent coalitions of cells that represent our knowledge and our skills. The existence of one hundred million million modifiable connections within our brains surely helps to explain how it is we acquire the ‘manners that maketh man’. Our extended childhoods maximise our opportunities to do so, and the neural plasticity that allows us to learn as children persists into maturity, enabling us to remain adaptable as adults: our nature is inventive and naturally curious, and many of us remain avid to learn new tricks throughout our lives.

Next, we possess a cluster of abilities that help to keep us social, but that are based, to a greater or lesser extent, in the individual brain – our ability to use symbols, our capacity to ‘mind read’ and our possession of ‘mirror neurons’. The degree to which our use of symbolic language is a specifically evolved ability, as opposed to a manifestation of our high level of general intelligence, remains controversial. But there is no doubt that language has found a congenial, and surely somewhat specialised, home for itself within the human brain: we have known since the 19th century that language is mainly represented in the brain’s left hemisphere, the hemisphere that also controls our (usually) dominant right hand. The neurologists Pierre Broca and Carl Wernicke established that regions in the frontal lobe and temporal lobe play critical roles, respectively, in the fluent programming and comprehension of language. Language may not be the single cornerstone of human cognition – but try to imagine human culture without it and its importance becomes clear.

One reason for questioning whether language is the cornerstone of human cognition is that language itself appears to depend on other, arguably more fundamental, skills. One of these has come to be called our ‘theory of mind’. There is little doubt that many other animals, like us, have awareness both of the world and of their inner states such as hunger or pain. There is good evidence that some other animals, for example chimps, have a self-concept – enabling them to recognise themselves in a mirror. But so far it looks as if we may be the only creature on earth to take the further intellectual stride that enables us to become aware of ourselves not just as objects, possessors of physical bodies, but as subjects of experience, possessors of minds. We deploy our theory of mind constantly – I am bearing your mind in mine as I write, asking myself whether you will be able to make sense of what I’m saying. Scarcely a minute passes when we do not wonder what another person might be thinking, believing, remembering, plotting, and we are capable of remarkable feats of nested attribution: I think that you imagine that I want you to believe that understanding the brain will  help to explain human culture. Theory of mind interacts with language use – working out what someone means to say often requires an attempt to work out what they might be intending – and in people with autism, impairment of language use and of theory of mind appear to go hand in hand. Contemporary neuroscientists are chasing the cerebral basis of theory of mind, just as Broca and Wernicke sought the basis of language, and a network of brain regions involved in ‘social cognition’ is indeed beginning to emerge.

One mechanism, in particular, that may help to explain our capacity to inhabit each others’ experience, as we often do when we empathise with a friend’s story, or become absorbed by a film or novel, has won fame recently in neuroscience. ‘Mirror neurons’ are brain cells that become active both when one performs an action, say reaching for a cup, and when one observes another person doing so. Their existence suggests that perceiving the actions of others partly involves unconscious preparation to perform the same actions onseself. No effortful inference is required to work out what someone is intending – we experience their act in our own as we observe them. What is true for action appears true also for emotion. The amygdala, for example, a brain region which plays a key role in fear, becomes active when we are fearful, but also when we see a fearful face or hear a fearful voice. The mechanisms of action and emotion in the brain enable us to enter directly into others’ experience because we perceive their actions and emotions at least partly through the medium of our own.

Language, theory of mind, mirror neurons help to explain our sociality, and how cultural change comes to be so easily transmitted through the tribe. Another, more introverted, set of capacities is perhaps more relevant to the creativity that drives cultural change. Consider what you are doing at this moment. Rather than servicing your body, with food, drink or pleasure, rather than provisioning your larder or shoring up your shelter, you have set aside the demands of the here and now to take some time to think. This surely is one of our most deeply human tendencies – to detach ourselves from the present, to travel mentally into the past and to contemplate the future, to enter possible worlds remote from our immediate experience, conjured up by art or science or our own teeming imagination. This capacity is powerful and poignant – powerful, because by allowing us to dream of how things might be, it gives us the opportunity to realise fabulous possibilities, poignant, because it can condemn us to imagine possibilities we long for but cannot bring about.

Cultural creaturesWe know something about what makes imagination possible in the brain. Take a simple case. Close your eyes and imagine an apple – go on… What did you see? A Granny Smith, a Cox’s, a Braeburn, the Golden Apple of mythology, or one of Robert Frost’s ‘load on load of apples coming in’? If you tried and succeeded – as most of us can – you should be able to answer this question. While you held the image of the apple in your mind’s eye, you were activating regions of the brain that would normally become active when you look at a real apple. The activation was weaker than when you see the real thing, but nonetheless detectable using modern methods of brain imaging. Here then is part of the secret of imagination in the brain. We have evolved an organ that is sensitive to the world around us and to our own internal states, of pain, say, or desire. We have also evolved the ability to play this instrument off-line, summoning up the shades and colours of experience as we sit in our armchairs. When imagination remains faithful to what has happened in the past, we call the result recollection. But if we allow ourselves a little freedom to rearrange and modify the elements of our experience, the result is creativity.

Imagination in the brain involves another element. The visual areas that sustain the image of your favourite apple do so at the bidding of regions elsewhere that organise our thinking and behaviour. The visual areas lie at the back of the brain; the ‘executive’ regions, that issue orders, lie at the front. Our capacity to detach ourselves from the here and now, indeed our self-control in general, depends on this executive system which is especially well-developed in the human brain. If any brain region sprang into life when Eve bit into the forbidden fruit of knowledge, it was surely this region of the frontal lobes, setting us free from the tyranny of the present while simultaneously opening up our poignant knowledge of the gulf between what is and what might be.

There is one final ingredient in the recipe for innovation. It is the most anarchic, the least predicable, the joker in the pack. Creative ideas, in the sciences and the arts, have a habit of appearing unexpectedly. They seem to require some lack of inhibition, some playfulness, some willingness to receive the gifts of the unconscious brain. Notoriously, plots, poems, tunes, mathematical solutions, illuminating metaphors can arrive in their creators’ minds when they are least expected – on waking, in the bath or on a run. They have something in common with dreams, those remarkable acts of invention which reveal the highly patterned working of our brains and minds – patterned even, or perhaps especially, at moments of improvisation. The chance to become attuned to this creative source of invention is one of the rewards of creativity.

So – we are naturally cultural animals, equipped with brains that have evolved to acquire and create culture. Our capacity to learn underpins its importance in our lives; our language, theory of mind and mirror cells provide the cognitive foundations that allow it to propagate; our abilities to detach ourselves from the here and now and to create other possible worlds help to drive cultural change. All these capacities have biological roots which we are just beginning to fathom. Can we learn anything useful from this stripling neuroscience of culture? The story of human evolution indicates that culture, hand in hand with the brain that it has created and which creates it, has been the key to human success. But this particular form of success comes at a price, a price that we can perhaps reduce once we become aware of it.

Our irrepressible tendency to innovate is a constant source of cultural differences which come to matter to us hugely – our particular creed, our culinary preferences, the arcane rules of our favourite sports, our fashions. We can’t stop ourselves building towers of Babel. These differences are bound to matter to us, deeply cultural creatures that we are, and it is right that we should celebrate them: for indeed ‘manners maketh man’. But the natural history of culture, briefly sketched here, urges tolerance if nothing else. The ways of others are, like our own, the outcome of cultural traditions that might have grown quite differently. We cannot escape our tribalism, but should be willing to acknowledge that our traditions are the malleable products of imaginative brains. This may protect us from a recurring danger posed by our tribalistic tendencies, the risk of enslavement to appealing but seriously bad ideas – fundamentalist religion, the worship of political leaders, Cultural Revolutions come to mind.

Cultural creatures are driven by two opposing tendencies, both crucial to our way of life: we are inveterate rule makers and inveterate rule breakers, bound equally to conform and to innovate. We must live by laws that only we invent – and only we can change. Tradition and innovation are twin expressions of the human spirit, reflections of the importance of learning and imagination. All these capacities can be traced back to the workings of our brains. This is because, a little paradoxically, these capacities are among the potent forces that have shaped our human brains.

Adam Zeman is professor of cognitive and behavioural neurology at the Peninsula Medical School.