pedigree of crooks and criminals. He probably killed Collins because his genes made him do it. 'He' was not responsible; he was a genetically determined automaton.
Mobley was happy to surrender his illusion of free will; he wanted F R E E W I L L 3 0 9
it to be thought that he had none. So does every criminal who uses the defence of insanity or diminished responsibility. So does every jealous spouse who uses the defence of temporary insanity or justifiable rage after murdering an unfaithful partner. So does the unfaithful partner when justifying the infidelity. So does every tycoon who uses the excuse of Alzheimer's disease when accused of fraud against his shareholders. So indeed does a child in the playground who says that his friend made him do it. So does each one of us when we willingly go along with a subtle suggestion from the therapist that we should blame our parents for our present unhappiness. So does a politician who blames social conditions for the crime rate in an area. So does an economist when he asserts that consumers are utility maximisers. So does a biographer when he tries to explain how his subject's character was forged by formative experiences. So does everybody who consults a horoscope. In every case there is a willing, happy and grateful embracing of determinism. Far from loving free will, we seem to be a species that positively leaps to surrender it whenever we can.5
Full responsibility for one's actions is a necessary fiction without which the law would flounder, but it is a fiction all the same. To the extent that you act in character you are responsible for your actions; yet acting in character is merely expressing the many determinisms that caused your character. David Hume found himself impaled on this dilemma, subsequently named Hume's fork. Either our actions are determined, in which case we are not responsible for them, or they are random, in which case we are not responsible for them. In either case, common sense is outraged and society impossible to organise.
Christianity has wrestled with these issues for two millennia and theologians of other stripes for much longer. God, almost by definition, seems to deny free will or He would not be omnipotent. Yet Christianity in particular has striven to preserve a concept of free will because, without it, human beings cannot be held accountable for their actions. Without accountability, sin is a mockery and Hell a damnable injustice from a just God. The modern Christian consensus is that 3 1 0 G E N O M E
God has implanted free will in us, so that we have a choice of living virtuously or in sin.
Several prominent evolutionary biologists have recently argued that religious belief is an expression of a universal human instinct
— that there is in some sense a group of genes for believing in God or gods. (One neuroscientist even claims to have found a dedicated neural module in the temporal lobes of the brain that is bigger or more active in religious believers; hyper-religiosity is a feature of some types of temporal-lobe epilepsy.) A religious instinct may be no more than a by-product of an instinctive superstition to assume that all events, even thunderstorms, have wilful causes. Such a superstition could have been useful in the Stone Age. When a boulder rolls down the hill and nearly crushes you, it is less dangerous to subscribe to the conspiracy theory that it was pushed by somebody than to assume it was an accident. Our very language is larded with intentionality. I wrote earlier that my genes built me and delegated responsibility to my brain. My genes did nothing of the sort. It all just happened.
E. O. Wilson even argues, in his book
So even determinists can escape determinism. We have a paradox.
Unless our behaviour is random, then it is determined. If it is determined, then it is not free. And yet we feel, and demonstrably are, free. Charles Darwin described free will as a delusion caused by our inability to analyse our own motives. Modern Darwinists such as Robert Trivers have even argued that deceiving ourselves about such matters is itself an evolved adaptation. Pinker has called free will 'an idealisation of human beings that makes the ethics game F R E E W I L L 3 1 1
playable'. The writer Rita Carter calls it an illusion hard-wired into the mind. The philosopher Tony Ingram calls free will something that we assume other people have — we seem to have an inbuilt bias to ascribe free will to everybody and everything about us, from recalcitrant outboard motors to recalcitrant children equipped with our genes.7
I would like to think that we can get a little closer to resolving the paradox than that. Recall that, when discussing chromosome 10, I described how the stress response consists of genes at the whim of the social environment, not vice versa. If genes can affect behaviour and behaviour can affect genes, then the causality is circular. And in a system of circular feedbacks, hugely unpredictable results can follow from simple deterministic processes.
This kind of notion goes under the name of chaos theory. Much as I hate to admit it, the physicists have got there first. Pierre-Simon de LaPlace, the great French mathematician of the eighteenth century, once mused that if, as a good Newtonian, he could know the positions and the motions of every atom in the universe, he could predict the future. Or rather, he suspected that he could not know the future, but he wondered why not. It is fashionable to say that the answer lies at the subatomic level, where we now know that there are quantum-mechanical events that are only statistically predictable and the world is not made of Newtonian billiard balls. But that is not much help because Newtonian physics is actually a pretty good description of events at the scale at which we live and nobody seriously believes that we rely, for our free will, on the probabilistic scaffolding of Heisenberg's uncertainty principle. To put the reason bluntly: in deciding to write this chapter this afternoon, my brain did not play dice. To act randomly is not the same thing as to act freely — in fact, quite the reverse.8
Chaos theory provides a better answer to LaPlace. Unlike quantum physics, it does not rest on chance. Chaotic systems, as defined by mathematicians, are determined, not random. But the theory holds that even if you know all the determining factors in a system, you may not be able to predict the course it will take, because of the 3 1 2 G E N O M E
way different causes can interact with each other. Even simply determined systems can behave chaotically. They do so partly because of reflexivity, whereby one action affects the starting conditions of the next action, so small effects become larger causes. The trajectory of the stock market index, the future of the weather and the 'fractal geometry' of a coastline are all chaotic systems: in each case, the broad outline or course of events is predictable, but the precise details are not. We know it will be colder in winter than summer, but we cannot tell whether it will snow next Christmas Day.
Human behaviour shares these characteristics. Stress can alter the expression of genes, which can affect the response to stress and so on. Human behaviour is therefore unpredictable in the short term, but broadly predictable in the long term. Thus at any instant in the day, I can choose not to consume a meal. I am free not to eat. But over the course of the day it is almost a certainty that I will eat.
The timing of my meal may depend on many things — my hunger (partly dictated by my genes), the weather
