What Can Science Tell Us About Human Nature?
by Kenan Malik
'What can science tell us about human nature?'
Can be broken down into two more basic questions:
1. How does science know about the world?
2. How does human nature fit into the world?
In other words, what tools does science possess, and are those tools
sufficient for understanding that which is human nature. Not just in
science, but in all aspects of life, how you do something – the tools
that you utilise – determines what you can do. If you try to mow your
lawn using a pair of nail scissors you won't get very far. Nail scissors
places constraints on what you can do to a lawn.
I want to suggest, in a similar way, that the way that science
understands the world places constraints upon the way it can
understand human beings. A paradox of science is that its success in
understanding nature has created problems for its understanding of
human nature.
Let us begin with the question, 'How does science know about the
world?'
The success of science derives from the way that it has 'disenchanted'
the natural world. Whereas the prescientific world viewed the universe
as full of purpose and desire, the scientific revolution transformed
nature into an inert, mindless entity.
At the heart of the scientific methodology is its view of nature, and of
natural organisms, as machines; not because ants or apes work like
computers or TVs, but because, like all machines, they lack agency
and will. Animals are objects of natural forces, not potential subjects
of their own destiny. They act out a drama, not create one.
Humans, however, are not disenchanted creatures. We possess
purpose and agency, consciousness and will, qualities that science has
expunged from the rest of nature. Uniquely among organisms, human
beings are both objects of nature and subjects that can shape our own
fate. 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.
Two important expressions of the way that human subjectivity
distinguishes us from the rest of the natural world: our ability to make
history, and our ability to advance science.
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 chimpanzee have barely changed. Human behaviour and
lifestyles clearly have. Humans learn from previous generations,
improve upon their work, and have established a momentum to
human life and culture that has taken us from cave art to quantum
physics and the conquest of space. It is this capacity for constant
innovation that distinguishes humans from all other animals. All
animals have an evolutionary past. Only humans make history.
And only humans make science. All non-human animals are
constrained by the tools that nature has bequeathed them through
natural selection. They are incapable of striving towards truth; they
simply absorb information, and behave in ways useful for their
survival. The kinds of knowledge they require of the world have been
largely pre-selected by evolution. 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.
Some Darwinists have come to believe that there are indeed certain
questions that humans are incapable of answering because of our
evolved nature. 'Our minds evolved by natural selection to solve
problems that were life-and-death matters to our ancestors, not to
commune with correctness or to answer any question we are capable
of asking', argues Steven Pinker. 'We cannot hold ten thousand words
in our short-term memory. We cannot see ultra-violet light. We
cannot mentally rotate an object in the fourth dimension. And perhaps
we cannot solve conundrums like free will and sentience.'
Whether or not this is true remains to be seen. What we do know,
however, is that most scientific problems – from the structure of DNA,
to the physical composition of the sun, to the mechanism of evolution
– are problems that would not have been 'life-and-death matters to
our ancestors'. We have solved them despite our evolutionary legacy,
not just because of it. The development of science requires mental
skills, many of which are evolved adaptations. But it also requires us
to transcend those adaptations. We are only able to do science, in
other words, because we are able to transcend our evolutionary
heritage, because we are able to act as subjects, rather than as
objects.
All of which brings us back to our two questions:
1. How does science know about the world?
2. How does human nature fit into the world?
Science understands the world by treating as an object or a machine.
Science is mechanistic. Science is designed to understand phenomena
that are objects. Humans are distinct from the rest of the world by
virtue of being subjects. So, now we are faced with a third – and
crucial question - how can a tool designed to understand objects tell us
anything about phenomena that are also subjects– in other words
about human beings?
There are three broad answers to this question that I want to look at.
The first answer is that humans are not really subjects, that in reality
we are simply objects like every other natural being. Teleology is an
illusion, something that natural selection has designed us to believe in,
not because it is true but because it is useful. As the neuroscientist
Colin Blakemore has put it, when 'we feel ourselves to be in control of
an action, that feeling itself is the product of our brain, whose
machinery has been designed, on the basis of its functional utility, by
means of natural selection.'
A variation on this argument is provided by the psychologist Susan
Blackmore who adopts Richard Dawkins' notion of a meme, a unit of
culture that inhabits, or rather parasitises, our brains. Blackmore
suggests that 'Instead of thinking of our ideas as our own creations,
and working for us, we have to think of them as autonomous selfish
memes, working only to get themselves copied.'
Since 'we cannot find either beliefs or the self that believes' by looking
into somebody's head, she argues, so we must conclude that there are
no such things as beliefs or selves, 'only a person arguing, a brain
processing the information, memes being copied or not.'
There are lots of arguments against this view. But consider just this
one. From an evolutionary point of view, truth is contingent. Darwinian
processes are driven by the need, not to ascertain truth, but to survive
and reproduce. Of course, survival often requires organisms to have
correct facts about the world. A zebra that believed that lions were
friendly, or a chimpanzee that enjoyed the stench of rotting food
would not survive for long. But although natural selection often
ensures that an organism possesses the correct facts, it does not
always do so. Indeed, the argument that consciousness and free will
are illusions designed by natural selection relies on the idea that
evolution can select for untruths about the world because such
untruths aid survival.
If, then, our cognitive capacities were simply evolved dispositions,
there would be no way of knowing which of these capacities lead to
true beliefs and which to false ones. As the philosopher Thomas Nagel
points out, there would be no basis on which to trust reason itself. To
accept the truth of reasoning, Nagel observes, 'I have to be able to
believe… that I follow the rules of logic because they are correct – not
merely because I am biologically programmed to do so.'
In other words, if we were simply natural beings like every other
natural being, then science would simply be an evolved way of looking
at the world, not a means to ascertain objective truths. The logic of
the argument put forward by Colin Blakemore and Susan Blackmore
undermines our confidence in its own veracity. For if we are simply
sophisticated animals or machines, then we cannot have any
confidence in the claim that we are only sophisticated animals or
machines. We are only able to do science because we are able to
transcend our evolutionary heritage, because we are able to act as
subjects, rather than as objects.
For these and many other reasons, many people find implausible the
notion that human agency is an illusion and the self just a story. They
therefore adopt a different approach – accepting, in principle, the
existence of consciousness and free will, but ignoring them in practice
when formulating scientific concepts of human nature.
Steven Pinker, for instance, is 'as certain that I am sentient as I am
certain of anything.' Moral reasoning, he points out, depends upon our
acknowledgement of ourselves as sentient beings. The concept of
sentience 'underlies our certainty that torture is wrong and that
disabling a robot is the destruction of property but disabling a person
is murder.' Pinker acknowledges that, as yet, we have no idea how to
explain sentience scientifically. But, he argues, 'Our incomprehension
of sentience does not impede our understanding of how our mind
works.'
It seems bizarre to hold that sentience is both central to human
thinking and also irrelevant to our understanding of how the mind
works. As writer and neuroscientist Ray Tallis points out, to construct
a theory of the human mind while ignoring sentience is a bit like
'trying to build a house by starting at the second floor'. Sentience,
Tallis observes, 'is the first, not the last, problem… of psychology. It is
not merely the most difficult of the problems of consciousness or
mind; it is also the pivotal one and addressing it cannot be postponed
until one has solved the "easier" problems such as those pertaining to
"cognitive functions" like intelligence, memory, thinking etc.'
Tallis here raises the central problem in trying to apply to the
subjective world the types of reductions that one applies to the natural
world. The natural world works essentially from the 'bottom up'. The
laws of physics are the most fundamental because they constrain all
other natural phenomena.
There is a certain unity of nature so that, as the sociobiologist EO
Wilson has put it, 'quantum physics… blends into chemical physics,
which explains atomic bonding and chemical reactions, which form the
foundation of molecular biology, which demystifies cell biology', and so
on. Such reductionism allows one to imagine the universe as a unitary
body, but one in which phenomena form a hierarchy of 'levels',
whereby the laws and principles of a higher level fold into those of
more general, and hence fundamental, levels. A primatologist
understands the behaviour of chimpanzees in its own terms, through
the use of behavioural and mentalistic concepts. But he also
understands that such behaviour can be understood in
neurophysiological terms, and that the physiology of neurones can in
turn be understood at a more fundamental level through the laws of
chemistry, and so on.
The social world, however, because it embodies teleology or
purposiveness, often works from the 'top down'. The 'higher' levels
often influence the workings of the 'lower' ones. Consciousness
shapes the workings of 'lower' cognitive functions. Individual
behaviour is often driven by will and purpose. Social and historical
forces can determine the way in which individuals think or behave.
Humans make history, but in the process history helps remake the
kind of humans that we are.
All of which leads me to the third answer to the question: how can a
tool designed to understand objects tell us anything about phenomena
that are also subjects? My answer: Natural science can tell us much
about being human insofar as we are objects, but is constrained in
what it can tell us about humans as subjects.
Humans are physical beings and evolved creatures. Our evolutionary
heritage plays an important part in many aspects of human behaviour,
from phobias to sexual desire. Recent advances in evolutionary
biology, neurology, genetics and AI have certainly told us much about
human nature changed our perceptions of it. We no longer, for
instance, think of newborn babies as blank slates, and we've begun to
unravel the genetic roots of many behaviours from schizophrenia to
autism.
Yet however much we learn about our brains, our genes or our
evolutionary history, we will not fully learn what it is to be human.
Why? But because a discipline such as evolutionary psychology or
genetics inevitably understands us simply as objects, rather than as
subjects, and hence is limited in its understanding of the human
condition.
I am not saying that human nature cannot be fully understood. I am
saying that they cannot be fully understood as natural beings.
The distinction I am drawing is between what we might call the three
Ms – mechanistic, mysterian and materialist views of humanity. A
mechanistic view sees human beings largely as objects through which
nature acts. A mysterian view suggests that there are aspects of
human existence not knowable to mere mortals.
A materialist view, on the other hand, understands humans beings
without resort to mystical explanations. But it also sees humans as
exceptional because humans, unlike any other beings, possess
consciousness and agency. And understanding human consciousness
and agency requires us to understand humans as not just as natural,
but also as historical and social, beings.
These notes were written for The Great Debate day school held
in May 2001 entitled
Modern Theory and the
Human Mind.
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