And just as animals and children are alike in not registering disgust, so both constituencies are apparently capable of other emotions in the ‘universal’ portfolio, such as happiness. Even a rat will work at pressing a bar, instead of eating, to stimulate electrically its brain in certain areas operationally dubbed ‘pleasure centres’. Of course we will never know what someone else, let alone a member of another species, is actually feeling – but on the face of it a purring cat or tail-wagging dog is not that far removed from a gurgling, smiling baby. Similarly, the sadness that a small child might experience on losing a toy could be compared with that of a dog, listless, with tail between legs, who has lost a human or canine companion. Undoubtedly positive and negative feelings – let's not even call them happiness and sadness – can be generated in non-human brains. So we cannot simply equate basic, ‘universal’ emotions with human nature exclusively.
Some thirty years ago the biologist Edward O. Wilson argued strongly for the durability of human nature, which he defined as ‘those deeply embedded laws of behaviour that shape society, technology and culture’. These traits and tendencies have conferred selective advantages, such as cooperation, spirituality and tool-making. Nothing has changed for 100,000 years and thus, he argues, nothing is likely to change in the foreseeable future. According to Wilson humans will always show a tendency towards hierarchy; personal concern for status; value for self-esteem; desire for personal privacy, including space; deep sexual and parental bonding; aversion to incest; and tribalism of some kind, even, presumably, of soccer teams. We can also add a desire for tranquillity; for independence; for power; for excitement; for a sense of order; a predisposition to laughter; and above all the need, however vague, for fulfilment. Wilson describes as the ‘human condition’ the sad fact that hatred and aggression coexist with a sense of ethics. Promiscuity is ‘not in human genes’ so, Wilson says, the family unit is secure.
The list may offer a good series of examples of human nature but we might come up with others, such as desire to personalize the workspace, or predisposition for curvy corridors. Surely more important than anything, therefore, is not drawing up ever longer inventories of different instances of human nature but rather exploring what the diverse instances on that list all have in common. We need to identify the crucial single factor that is so basic that it is independent of different environments yet so sophisticated that it is exclusively human, indeed, according to Wilson, present exclusively in human genes – presumably the 1 per cent of DNA that differentiates us from chimps.
The psychologist Steven Pinker has taken the baton from Wilson and has more recently argued eloquently against the idea that the human mind is a tabula rasa – a blank slate. Despite the brain's plasticity, its large-scale organization is undoubtedly ‘genetic’, and the small number of genes – still 30,000 at least – are not really as nugatory as all that. This number has turned out to be substantially less than that predicted in Wilson's era, prior to the mapping of the genome; but Pinker points out, pondering how different mutations in genes could lead to large numbers of different permutations and indeed how combinations of genes could yield a very large number of different possibilities, that a ‘combinatorial’ approach to gene expression paints a far richer landscape. The relatively paltry ratio of genes to brain connections poses no problem if we remember how many different combinations can be derived from a limited number: for example, even a group of just 6 components can generate 720 different combinations!
Indeed, Pinker says, this combinatorial way of looking at the brain might explain how innate behaviours come about. Genes can work together so that different combinations exceed the number of component parts – macro brain-structures could do likewise. In normal circumstances the innate tendency to violence would be offset by another ‘natural’ brain system that suppressed such behaviour. So the idea that we have natural tendencies is not as scary as all that, since human nature is usually well equipped to prompt a balanced repertoire of action.
But we cannot, as Wilson did, assume that anything as universal as human nature would simply be wired into our genes. Let's briefly revisit the old nature-nurture issue discussed in Chapter 5. Genes are operative not just in the womb but are switched on and off continuously throughout life; moreover they are necessary but far from sufficient factors in determining brain function. So the issue of whether a behaviour is attributable to nature or nurture is quite meaningless.
To recap: a gene triggers the manufacture of a protein, which in turn has a vast range of actions at the molecular level of brain operations, be it the synthesis or removal of a transmitter, or some form of cellular housekeeping or indeed triggering neuronal suicide (apoptosis) – to cite just a few examples. These myriad, basic biochemical mechanisms are exploited in different ways and at different times in different brain regions, which impacts indirectly, and in ways we still do not really understand, on overall brain function and hence finally on outward behaviours. The gene is activated to start off this process not by a wayward agenda of its own but by local chemicals in the nucleus of the cell.
These chemicals can be released locally within the cell at certain stages of development, but in all cases they are not unleashed in a vacuum of isolation. Rather, throughout life different agents activate different genes and switch them off again, to manufacture different proteins to meet different requirements. Sure, sometimes these may be the natural innate requirements of development, but as likely as not they will be switched on by a cycle of events that can be traced back to something in the environment outside of the brain itself – within the mother's womb, or internal systems of hormones washing through the body. But it is the endless interaction between the individual and the external world ‘out there’ that drives a ceaseless configuring and reconfiguring of brain connections, through the switching on and off of genes. So a gene is simply a tool, one cog in the sophisticated biochemical machinery that translates each influence from an external environment into a physical shift in the pattern of brain connections.
It is therefore impossible to label an emergent behaviour with a nature or nurture provenance. True, there are the twin studies we spoke of earlier, which have found similar dispositions in identical twins reared apart. Some point to an eerie similarity in such cases. However, where this is the case the similarity cannot necessarily be specifically located in precise genes – for example, if both twins had a similar predilection for choosing polka-dot ties, it would not prove that there is a ‘gene for’ love of polka-dot ties. It would be more accurate to say instead that given identical genomes and exposure to similar, usually middle-class environments, similar quirks and habits may emerge in a set of identical twins. We would need to factor out the environment altogether – so far there have been no cases, say, of one twin brought up in New York and one in the Amazonian rainforest – or we would need to know the exact extent to which any happenstances in their domestic lives or cultural environments really contributed to the entire global mindset of each twin.
A far more interesting question, in any case, is whether or not that quirky common trait, say affection for polka-dot ties, would qualify as ‘human nature’ simply because it has a strong ‘genetic’ component. After all, a shared liking for wearing polka-dot ties is remarkable, surely, precisely because not all of us have that trait. So what is human nature, in biological terms? Obviously it is an umbrella term for certain types of behaviour, but one that needs a tighter definition than merely that of having a strong genetic element. Genes, because they are part of the building blocks of the brain, are clearly involved in any behaviours that are attributable to the generic aspects of the human brain – but they are also, by definition, part of what constitutes the non-generic aspects of an individual. Genes, then, will not help us understand the quintessential quality of human nature. Let's look to an older approach.
Way before the famous double helix of DNA was discovered, and the subsequent revolution in gene understanding and technology transfo
rmed biomedical science, Sigmund Freud worked out a framework for making sense of behaviours that were all too human. Unable to refer to maps of the human genome and appropriately discouraged from incursions into the physical brain by the primitive neurology and essentially non-existent neurosurgery of his day, Freud had to make do with abstract concepts. Nonetheless, as we all know, his theoretical structure of the generic aspects of the human mind persists to this day: a primitive and universal tendency, common to all animals, towards destruction and creation – the ‘id’ – the expression of which is channelled by an ‘ego’ and kept in check by a moralistic ‘superego’. It is the ego and superego that distinguishes humans from other animals, but all our behaviours could be stripped down and interpreted as driven by the primitive urges emanating from the id.
This notion was progressed in the early decades of the 20th century by the zoologist Konrad Lorenz, who saw everything we do in terms of the discharge of basic drives. To a certain extent this view of behaviour as ‘drive-discharge’ makes sense: you are hungry and initiate behaviour to reduce that drive, similarly for sexual desire or sleepiness. But these behaviours are common to all animals, and the fact that we suppress them or devise indirect means of attaining them does not in itself explain the essence of human nature. After all, dogs, cats and certainly primates engage in complex and indirect strategies to achieve a desired endpoint. Again, what is so special about us humans?
If it is not our emotions, or our genes or our basic drives, then where to turn next? Rather than extrapolate from biology perhaps it would be better to work in the opposite direction: let's try to find a good social encapsulation of the non-animalistic yet pan-cultural essence of human nature, and then see how it might be accommodated ‘scientifically’ within the physical brain.
The seven deadly sins are all exclusively human, and yet the whole point of their biblical catalogue is that they are universal to all times and cultures. But there is something about the list that distinguishes the pursuits of avarice, lust, gluttony, sloth, anger, envy and pride from the universal animalistic drive-reduction behaviours of sex, eating and sleeping. Perhaps the essence of the sins, why they are just that, is the element of excess – too much sex, too much food, too much sleep, too much aggression, beyond what is physiologically needed to sate the natural drives for survival. As for avarice, envy and pride, they are even further removed from crude biological drive reduction but they also evoke excess, within the individual and, more particularly, how that individual fits within the context of their society – their status.
We might overeat because we seek solace for not being loved or fully appreciated; excessive numbers of sexual partners may bring high status among our peers; hoarding of money may reflect the desire to seem important through wealth; resentment of someone perceived to have higher status than oneself is dependent on certain pan-cultural values; those same values, if promoted excessively in the self, are labelled pride; laziness is judged to be so only when certain expectations of one's behaviour are not met; finally anger, contrasted with more straightforward animal-like aggression, implies inappropriate excess, with a causation that is arbitrary, dependent on more ambiguous cultural or even personal values.
Obviously, this is an extremely limited list of examples of phenomena that could be realized in many different ways, as well as being, in psychiatric terms, probably extremely naive and far from accurate; but nonetheless it shows how the seven deadly sins, capturing as they do the universality yet uniqueness of human nature, can be couched in terms of not just certain cultures and values but cultures and values in general. Human nature is not as biologically basic as mere drive reduction, or as highly personal as liking specifically polka-dot ties. Rather, human nature is a generalized umbrella term for behaviours that depend on status and social values. The cultures and values may vary, but the behaviours do not. The really important distinction to grasp is that diverse cultures and values determine when and how the behaviours manifest themselves, but the behaviours themselves are recognizable as uniform, above and beyond the particular context in which they occur. Now let's take this idea back to the physical brain.
First we need to go back in time. The archaeologist Steven Mithen has questioned what might have accounted for the sudden explosion, some 100,000 years ago, of intelligence in Homo sapiens, and the subsequent development of cave art, language and a host of other exclusively human-type ‘cultural’ phenomena. He suggests that language is just an example of a wider ability to ‘think metaphorically’, to see something in terms of something else. My favourite example from his book The Prehistory of the Mind is that of a tooth, discarded by some animal, lying in one's prehistoric path. A chimp is able to recognize the object, in isolation, as a tooth. However, humans can go one better and see it not just literally as the sharp white thing that is normally in the mouth but also metaphorically, as part of a necklace. Moreover, that necklace could then be worn as a symbol of status. Never ever do chimps – dextrous and organized in social hierarchies though they may be – sport necklaces as symbols of their status. We are pretty much unique, suggests Mithen, in seeing the world in this way, symbolically as well as literally. Language would be but one example – a particularly powerful one – of our wider human skill in the use of symbols.
So this ‘metaphorical’ ability of humans could be general enough to be universal, and indeed to encompass humanoid skills like language and art, yet at the same time be sophisticated and specialized enough to be clearly something beyond our basic animal instincts for drive reduction. Perhaps we could think of this broad-spectrum but very human tendency as an updated version of Freud's original ego.
But is this ego not, after all, genetic? Yes, in the sense that it is a feature of the generic human brain, but no, in that it would not be reducible to any one set of specialized genes that do not at the same time underlie the structure and function of the entire brain. The critical issue, then, is not genes per se, any more than transmitters or receptors or neuronal circuits; instead we should ask how all the biochemical baggage assembles into a cohesive operational system that not only coordinates the human body but also amounts to a human mind capable of living a life based on symbols. If human nature is no more and no less than our individualism, how is it grounded in the brain?
In the middle of the 20th century the biologist Paul MacLean effectively attempted a neuroanatomical description of human nature, although he didn't articulate his goal in quite that way. With shades of the Freudian compartmentalization of id, ego and superego, MacLean pointed to the most primitive part of the brain, the brainstem, as the source of our most basic ‘reptilian’ behaviours, what Freud would have labelled the province of the id. This reptilian aspect of our make-up is, MacLean suggested, kept in check by an overlying system, which he identified as the anatomically enfolding limbic system; in turn, this ‘mammalian’ brain is kept in check by the cortex, the outer layer of the brain, which increases in surface area, and hence is more crinkled, as the brain increases in sophistication. There are easy parallels between the ‘neomammalian’ brain of the cortex and Freud's superego. Although this is now regarded as simplistic and naive in terms of anatomical localization of function, MacLean made a nonetheless admirable attempt to explain the then recent behaviours of the crowds at the Nuremberg rallies in biological terms, in terms of human nature. His idea was this: what went wrong was that ‘reptilian’ crowd behaviour escaped from the normal constraints of the limbic system and was unleashed inappropriately.
But we have seen that there is more to human nature than a simple reversion to being a reptile. The hallmark of the quintessentially human brain is the ability to see things in terms of other things, metaphorically or symbolically. The seven deadly sins would be of no account on a desert island; they are relevant only when human beings start living in a group, a group with certain cultural values, when status counts. Conspicuous consumption, sexual popularity, having more money than anyone else and so on are all tied in with h
ow you the individual are perceived within the context of your culture, by others as well as by yourself.
Central to human nature, therefore, is the concept of the self, and that self will be defined and evaluated in the context of the society in which it lives. A small child feels pleasure from direct stimulation of the senses by the sun or the paddling pool, or the taste of chocolate, or bring rocked to sleep; but if his or her parents win the lottery, it will ‘mean’ little until he or she has learnt the value systems of the culture – more generally the highly complex, nested series of connections which will permit her to ‘understand’ the significance of what has happened. The lines from Macbeth spouted by my 3-year-old brother were, literally, meaning-less sounds until he was able to attach associations to words like ‘death’ and, even more advanced, to grasp the notion of an extinguished candle as a metaphor for the end of life. The more the child sees things in terms of other things, the more deeply they ‘understand’.
The formation of associations through individual experience – the personalization of the brain – is, we saw earlier, a talent of human beings par excellence. Because the rapid and highly adaptable formation of connections between neurons encompasses language skills, we are able to project ourselves away from the sensory present of the infant into a past and a future conjured up in our minds, and even describable in words or pictorial symbols to others. Above all, as this ability enables us to acquire a sense of the most abstract notion of all, the self, as we develop, we become self-conscious.
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