Can We Change Human Nature?
After decades of exile, the concept of human nature is back. It has been rehabilitated both by scientific findings that the mind has a universal, genetically shaped organization, and by philosophical analyses that have dispelled the fear that the concept is morally and politically tainted. So if human nature exists, can it be changed? Attempts to redesign human nature by directed evolution (eugenics) or directed social engineering (revolutionary utopianism) are generally recognized as futile, dangerous, and unnecessary to achieve moral and political progress. What about voluntary changes, such as parents genetically engineering their children? Despite widespread concern that human genetic engineering will change human nature, I present a number of reasons for skepticism that it will ever be a significant phenomenon.
- There is a built-in bias toward luridness and glibness among scientists and journalists who write about technological change over long time spans in the future. Their dramatic predictions rarely come true.
- Though we have good reason to believe that tens of thousands of genes acting in complex combinations affect mental abilities in the course of development, we have no reason to believe that a single gene (or a small number of them) could be inserted in a fetus to enhance mental abilities.
- Most genetic effects are probabilistic: identical twins, for example, are similar, but they are far from indistinguishable.
- The human species comprises six billion individuals whose mental traits vary quantitatively in statistical distributions. It would take an unimaginably massive intervention to shift these distributions significantly.
- Ethical constraints on experimentation with humans impose an impediment to research and development on human genetic enhancement, preventing the high-speed trajectories we have seen in other areas of technology.
- People make choices according to their costs and benefits, not according to their benefits alone. It is far from clear that the imaginable benefits of genetic engineering (such as a child with some probability of having a slightly higher IQ) will outweigh the costs, such as the trauma and expense of IVF, the risk of a deformed child, and violations of deep-seated intuitions about naturalness (which act as a brake on the acceptance of other technologies, such as genetically modified food). Similar skepticism should surround other claims about radical changes in human nature such as those surrounding enhancing drugs and human-machine interfaces. These uncertainties speak against restricting beneficial research on the basis of dystopian fantasies.
Before I get to the subject of human nature itself, I’d like to say a few words about the concept of human nature. Presently, we are witnessing a rediscovery of the concept of human nature. Part of this comes from common sense. Anyone who has raised a child knows that children are not indistinguishable lumps of putty waiting to be shaped. They come into the world with a distinct personality. The environment alone does not determine behavior. Innate abilities play a role. The concept of human nature has been also rejuvenated by the recent study of human universals, despite traditional anthropological emphasis on differences in culture, which, of course, can be profound. Finally, the importance of our genetic endowment has been highlighted by discoveries in behavioral genetics and cognitive neuroscience.
MRI images of related living human brains show that large amounts of gray matter are influenced by the degree of genetic similarity. These similarities are not just meaningless differences in anatomy, but have well-known consequences for intelligence and personality. Studies of identical twins separated at birth show astonishing similarities in personality, intellect, and many idiosyncratic personal quirks. So, if there is such a thing as human nature, we may well ask if we are able to change it.
There have been notorious attempts to change human nature in the twentieth century, like the New Socialist Man of Stalinist Russia, the coercive eugenics of Nazism, as well as milder forms which occurred in Western democracies. I will set these to the side and concentrate instead on a more benign form of changing human nature—namely voluntary genetic engineering. Many people believe that it is simply a matter of time before designer babies become a reality, and that we should anticipate and intervene now before it is too late.
I have a somewhat skeptical view of that inevitability. In fact, I have three reasons for thinking it highly unlikely that it will happen within our lifetime. The first is the historical fallibility of predictions about complex technology.
The second are the theoretical impediments to changing human nature that arise from the study of behavioral genetics. And third is some difficulties of changing human nature that arise from human nature itself.
Predictions about the future based on the development of complex technologies are notoriously unreliable. There are several reasons for this. First, is the fallacy of constructing a linear or exponential extrapolation for progress. Moore’s Law has been applied without justification to almost anything. Second, prognosticators often underestimate the number of things—technological, psychological, and sociological—that have to go exactly right for the projected scenario to take place. Third, many futurologists do not adequately consider the costs as well as the benefits of a new technology. Finally, there is the general built-in incentive for dramatic futurological predictions. People pay less attention to a prediction that things will be pretty much the same as they are now.
The prospect for designed babies is further qualified by what we already know about behavioral genetics and neural development. The most important of these findings is the rarity of single genes that have consistent beneficial psychological effects. Tens of thousands of genes working together have a large effect on the mind, but so far we have found no single genes that can explain schizophrenia, autism, or OCD, let alone talents like musical ability, likeability, intelligence, and so on. The human brain is not a bag of traits, with one gene for each trait. Neural development is staggeringly complex, with many genes interacting among each other in complex feedback loops. The effects of genes are often non-additive, and the pattern of the expression of genes is as important as which genes are present.
There are other impediments to genetic enhancement. Even identical twins raised in the identical environment don’t end up identically. Sheer chance and stochastic processes play an enormous and underappreciated role in making us who we are. Genes also have multiple dominance effects. The effect a gene has depends on what other allele it is paired with. Most genes have multiple effects, and evolution selects for the best compromise. There are also ethical impediments to research on human enhancement. We do not know how to make these processes safe or to weed out deleterious side effects. Finally, most genes are desirable at intermediate, not extreme, values.
Last of all, there are some impediments in human nature itself to enhancing it. Although it may be true that most parents wish for the best for their children and want to provide them with a competitive edge, an equally strong parental motivation is the wish to spare their children any harm or the risk of harm. We must also recognize the widespread aversion to artificial life forms and technologies that are viewed as sinister. For genetic enhancement to change human nature, not just a few, but billions would have to agree to it.
For all of these reasons—the complexity of neural development, the rarity of single genes with consistent beneficial effects, the tradeoffs of risks and benefits of genetic enhancement—I do not think that changing human nature by voluntary genetic enhancement is inevitable. An effective bioethics policy should acknowledge the unreliability of long-term technological predictions and base itself on fact, not the fantasy of exponential extrapolation.
The Future of Human Nature
The idea of human nature once was quite respectable in philosophy; but it came under attack from many quarters in the course of the 20th century, and has fallen into such disfavor that it now is rarely even mentioned in polite philosophical society, and is generally shunned in the curricula of mainstream philosophy departments. I consider this to be unfortunate; and, after a glance at this sorry history of the idea’s decline and fall, I argue that the time has come to resurrect it—or rather, to revisit and rethink it—in a manner that can and should give it a new lease on philosophical life. In doing so I make common cause with David Hume, and to an even greater extent with Friedrich Nietzsche, who is often (but quite wrongly) thought to be one of the arch-enemies of the very idea of human nature. Both were critics of metaphysical conceptions of some sort of human essence; but both were advocates of naturalistic reconceptions of our human nature, and of its philosophical investigation in a manner attuned if not restricted to what can be learned about it by way of the various human sciences. I suggest what some of the themes of such a “philosophical anthropology” might be, and conclude with a sketch of some of my own thinking along these lines, to give a more concrete indication of the sort of philosophical approach to the question of human nature that I believe has—or at any rate, deserves to have—a future.
I am in essential agreement with Steven Pinker’s position, although I will say a few other things later on which perhaps diverge from him. To start with, I would like to say something about what happened to the concept of human nature in twentieth-century philosophy, and then to go on to discuss David Hume and Friedrich Nietzsche, who powerfully and interestingly revived the concept. Finally I want to conclude, after speaking somewhat critically about the notion, to suggest some things that are still worth talking about.
The question of whether there is anything beyond the strictly biological that is true about human nature is still a subject of hot debate. Michel Foucault and his followers, for example, think that the idea is a nineteenth-century misunderstanding whose time has long passed. They admit that there are, of course, plenty of human beings around, but all of them are historically contingent affairs. They deny that there is anything like a blueprint of humanity that we all exemplify or ought to exemplify. These attitudes, extreme though they sometimes seem, are quite representative of many twentieth-century philosophers of various schools.
This, however, was not always the case. John Locke and David Hume both emphasized the concept, and French Enlightenment philosophers took up the idea with enthusiasm, as did Hegel. With Marx, Kierkegaard, and Nietzsche, however, the situation becomes more complicated. All three had deep and significant sets of reservations about the concept. A movement called philosophical anthropology revived some of these ideas in the 1920s, but it was overshadowed by Heidegger, the Second World War, and then by existentialism, Marxism, post-structuralism, and deconstruction.
Most twentieth-century schools of philosophy reject the notion of human nature as philosophically useful. Phenomenologists object to the idea of assuming that our nature is fundamentally human, and existentialists insist that existence precedes essence. They also think that the notion of human nature serves to help us avoid facing our ultimate freedom and responsibility. Marxists condemn the idea as a reactionary ideological construct intended to subvert the recognition for the need for a profound transformation of social and economic conditions. Similarly structuralists reject the notion for the way it detracts attention away from historically contingent arrangements.
Although many of these schools claim Nietzsche as their spiritual grandparent, my own reading of that philosopher finds him to be an important proponent of the concept. He was the heir of Hume, who proposed establishing a science of human nature. Nietzsche explicitly proclaimed his project of naturalizing ourselves in a newly redeemed notion of human nature and of attaining a kind of anthropological optic in thinking about philosophical questions. Although the common view of Nietzsche sees him as taking a strongly reductionist and bio-logistic point of view, I see him as thinking of animal life as having been transformed and shaped with the advent of society into human life, stressing both social and cultural phenomena. For him, our humanity has a history and a genelogy, and it remains capable of further transformation.
Human life for Nietzsche is both a biological and a socio-cultural affair. Social and cultural diversity stand in contrast to the relative constancy and uniformity of our biological constitution. Human life is open-ended with respect to the possibility of the emergence of new socio-cultural forms. That is why a good deal of what goes on in human life is not explicable in merely biological terms. This socio-cultural supervenience might be called our true supernaturalism. We are creatures of nature who have outgrown our animality. A thoroughgoing dialectic of nature and nurture makes it impossible to disentangle them.
Our human nature is therefore a question of biology, our historicality, and our psychosomaticity, which includes our senses, our emotions, and our sexualities. The dynamics of the interrelations between the psychosomatic and the socio-cultural are the heartbeat of humans. Another feature is objectification, the way subjectivity finds its objects in and undergoes transformation under the impact of humanly produced objectivities. Our nature also includes the phenomenon of human intersubjectivity, mediated by symbols, conventions, and institutions, but not fixed by any of their forms and structures. Another feature of our human existence is our relation to our own bodies, a thing we both have and are. In a similar way, we have both brains and minds. All this is bound up in the geneology of our humanity.
This is only a small list of topics that might constitute the agenda suggested by Hume and Nietzsche. It posits a notion of human beings quite different from that of traditional Western philosophy, starting from Plato. It also differs from the one we find among those who take a cognitive science point of view, which sees the mental dimension of human life as just disguised neurophysiological events. Although everything that goes on in us has these dimensions, such an analysis does not take us very far in understanding human reality, which finds its objective expression and embodiment in social and cultural phenomena.
The information we take in is schematized and bound up with the interpretive and evaluative contexts within which its meaning is constituted. We take in these systems, and, as we learn them, we make modifications and refinements. We relate to each other by means of them. These representations owe at least as much to the symbolic systems we internalize as to the sensory and neural apparatuses with which we are endowed. It is the meaning content of the representations, not the locus where such representations become effective, that is of paramount importance in human life. And that content requires an analysis that reflects its symbolic elaboration and socio-cultural objectification.
Nietzsche thought that we could make naturalistic sense of this project. We can imagine a Hobbsian creature, a body with a brain, entering into group arrangements that emphasize the development of communication and the coordination of behavior. These lead to more complex social arrangements and to further elaborated systems of conventions and rules. In addition, relations among elements can begin to affect their very use and function, and various social dynamics, in turn, can come to be reflected in them. The resulting conceptual, interpretative, and evaluative schemes come to structure ways in which human beings encounter each other. Their existence has come to be mediated by socially generated domains of symbolic phenomena. Psychosomatic human nature has not disappeared, but has been transmuted and superceded. And it has also entered into socially and symbolically constructed forms of life.
As human beings, we often do things in response to some event, signal, or communication in the socio-cultural world. The brain is certainly involved in this, but it is not the only party running the show. The brain makes our remarkable manner of existence possible. It determines what forms these social and symbolic structures will take and what courses of events will unfold. Other animals have brains, but they are quite oblivious to the sorts of things we respond to. This is because they lack minds. What is needed to mediate between symbolic systems and neural processes underlying behavior? There must be a way of internalizing them and representing their contents. In other words, there must be an intermediary between an objectified symbolic order and the neural order.
Our minds work with a kind of social symbolic education. We have a neural apparatus, but in describing it, we must remember the difference between the truth and the whole truth. I think that the idea of human nature does have a future and that a consideration of it from both philosophical and scientific points of view is not only possible, but quite interesting. It will, of course, remain a rather untidy and tentative affair. But the same is true with respect to human life itself.
This is a chapter from The Future of Human Nature: A Symposium on the Promises and Challenges of the Revolutions in Genomics and Computer Science (Conference).
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