'Are humans the products of nature or nurture?' There are few questions that
have produced more heated, but less illuminating, debates.
Over the past half century there has been a fierce dispute as to whether human
behaviour is determined by our genes or by our environment. In the decades
following the Second World War, the experience of racial science, eugenics
and the Holocaust led many scholars to denounce genetic theories of human
behaviour and to insist on the importance of nurture in shaping who we are.
More recently, disillusionment with social explanations, and advances in genetics
and evolutionary biology, have helped swing the pendulum back towards theories
that stress the importance of nature in the human make-up.
The latest round in the nature-nurture debate took place in the wake of the
publication in February 2001 of the first detailed analysis of the data from
the human genome project. This suggested that human beings possess far fewer
genes than previously thought; not the 100,000 genes that many had believed,
but more like 30,000. We have a genome barely bigger than that of corn plant,
and possess just 300 more genes than a mouse.
There have been two responses to these findings. For some, the fact that the
human genome appears different from that of lesser creatures seems to show
that there is nothing particularly special about humans. 'It's humbling isn't
it?', observed Ari Patrinos of the US Department of Energy, which funded much
of the public genome research. But why should it be? Perhaps we should rather
celebrate the fact that a creature with barely more genes than a cress plant
can nevertheless unravel the complexities of its own genome.
The second view is that the findings show that humans are more controlled
by nurture than by nature - that they provide an argument for the existence
of free will. 'We simply do not have enough genes for the idea of genetic
determinism to be right', claimed Craig Venter, the founder of Celera, the
private company which played a major part in the human genome project. An
editorial in the UK Observer suggested that 'we are more free, it seems, than
we had realised'. 'Politically', the editorial continued, the new research
'offers comfort for the left, with its belief in the potential of all, however
deprived their background. But it is damning for the right, with its fondness
for ruling classes and original sin'.
A moment's reflection should reveal how unfounded is the argument that fewer
genes means greater freedom. If it had turned out, for instance, that humans
possessed 200,000 genes, would that have implied that we are slaves to our
nature? And given that fruit flies possess half our number of genes, should
we consider them to be twice as free as we are?
That the UK Observer should seek political solace in the human genome
says more about the desperate character of contemporary social thought than
it does about the data emerging from the human genome project. There remains
considerable controversy about the extent to which heredity influences human
behaviour. But the argument for the importance of heredity has never rested
on arguments about the number of genes we might possess. Rather, it has emerged
largely from studies of identical twins. The interpretation of the data from
such studies may leave much to be desired, but handwaving about numbers of
genes will not make any difference to that data.
The fact that humans have fewer genes than expected does not mean that we
are governed more by nurture than by nature. Even if it did, however, it would
not imply that humans are 'more free'. Being controlled by one's environment
does not make one any freer than being controlled by one's genes.
The problem with the nature-nurture debate is that this is an inadequate way
of understanding human freedom. Like every other organism, humans are shaped
by both nature and nurture. But unlike any other organism, we are also defined
by our ability to transcend both, by our capacity to overcome the constraints
imposed both by our genetic and our cultural heritage. It is not that human
beings have floated free of the laws of causation. It is rather that humans
are not simply the passive end result of a chain of causes, whether natural
or environmental. We have developed the capacity to intervene actively in
both nature and culture, to shape both to our will.
To put this another way, humans, uniquely, are subjects as well as objects.
We are biological beings, and under the purview of biological and physical
laws. But we are also conscious beings with purpose and agency, traits the
possession of which allow us to design ways of breaking the constraints of
biological and physical laws.
All non-human animals are constrained by the tools that nature has bequeathed
them through natural selection, and by the environmental conditions in which
they find themselves. No animal is capable of asking questions or generating
problems that are irrelevant to its immediate circumstances or its evolutionarily
designed needs. When a beaver builds a dam, it doesn't ask itself why it does
so, or whether there is a better way of doing it. When a swallow flies south,
it doesn't wonder why it is hotter in Africa or what would happen if it flew
still further south. Humans do ask themselves these and many other kinds of
questions - questions that have no relevance, indeed make little sense, in
the context of evolved needs and goals.
What marks out humans is our capacity to go beyond our naturally defined goals
- such as the need to find food, shelter or a mate - and to establish human-created
goals. Our evolutionary heritage certainly shapes the way that humans approach
the world. But it does not limit it. Similarly, our cultural heritage influences
the ways in which we think about the world and the kinds of questions we ask
of it, but it does not imprison them. If membership of a particular culture
absolutely shaped our worldview, then historical change would never be possible.
If the people of medieval Europe had been totally determined by the worldview
sustained by medieval European culture, it would not have been possible for
that society to have become anything different. It would not have been possible,
for instance, to have developed new ideas about individualism and materialism,
or to have created new forms of technology and new political institutions.
Human beings are not automata who simply respond blindly to whatever culture
in which they find themselves, any more than they are automata that blindly
respond to their evolutionary heritage. There is a tension between the way
a culture shapes individuals within its purview and the way that those individuals
respond to that culture, just as there is a tension between the way natural
selection shapes the way that humans think about the world and the way that
humans respond to our natural heritage. This tension allows people to think
critically and imaginatively, and to look beyond a particular culture's horizons.
In the six million years since the human and chimpanzee lines first diverged
on either side of Africa's Great Rift Valley, the behaviour and lifestyles
of chimpanzees have barely changed. Human behaviour and lifestyles clearly
have. Humans have learned to learn from previous generations, to improve upon
their work, and to establish a momentum to human life and culture that has
taken us from cave art to quantum physics - and to the unravelling of the
genome. It is this capacity for constant innovation that distinguishes humans
from all other animals.
All animals have an evolutionary past. Only humans make history. The historical,
transformative quality of being human is why the so-called nature-nurture
debate, while creating considerable friction, has thrown little light on what
it means to be human. To understand human freedom we need to understand not
so much whether we are creatures of nature or nurture, but how, despite being
shaped by both nature and nurture, we are also able to transcend both.