Predestination by Genes



Kevin Sharpe with Rebecca Bryant

ABSTRACT. Genetic predisposition looks like a modern form of divine predestination. If it is, it is also a sophisticated form that allows us freely to work out our destiny in and from the cradle of the behaviors our genes predispose.


Apply intense heat to an ox scapula or a turtle shell and look carefully at the craze of cracks the heat produces. The future reveals itself in the craze. Wu shamans of the Shang dynasty in China practiced this art, called pyroscapulimancy, 3,000 years ago.

We have invented many means to predict the future. We want to know it. Those who do can prepare for it and thereby try to benefit from what happens.

A belief hides behind this fascination and desire for success, however, a belief whose grip can still hold us 3,000 years after the Wu shamans: that the future is knowable beforehand implies it is set or preordained. Nothing can change it.

God supposedly knows the future because God supposedly formed it. We must act the way God decided for us. A principle task of Christian theology is to explain how, in the presence of an all-knowing, all-powerful God, we have free will. If God knew or foreordained from eternity every choice we make and every move we take, how can we freely choose any decision or action? Free choice means that we could act differently from how we do act; hence, no one – not even God – can predict the course we take.

The idea of predestination offers a special case of this contradiction. All versions of predestination concern the possibility of salvation (will we go to heaven or not?) and all say that God knows whom God will save and that God will do what God says God will do. An extreme version known as “double predestination” – commonly associated with John Calvin – considers that God has, from eternity, determined whom to damn and whom to save, irrespective of their faith, merit, or love; our future for life in heaven or hell lies totally out of our hands. Now, suppose we are responsible for how we live. Suppose also that God has, for eternity, engineered everyone’s salvation or damnation. How then can we perform free actions that (at least partially) determine our futures and for which we stand responsible? The predestinarian must balance the idea that we depend utterly on God for our salvation, with an adequate account of freedom that allows us to take responsibility for our actions, independent of God. Predestination faces a catch-22 around the question of free will.

The science of behavioral genetics raises similar questions.

With recent advances in molecular biology and the use of in-depth twin studies, scientists are beginning to reveal that not only our physical characteristics – height, weight, hair and eye color – but also our personality traits involve a significant genetic component. Studies suggest that thrill seeking is 59 percent heritable, happiness 80 percent heritable, and assertiveness 60 percent heritable. Our genetic inheritance also apparently influences other behavioral attributes including leadership, religious belief, anxiety, extroversion, alienation, traditionalism, and career choice. Twin studies show the heritability of most personality traits at around 50 percent.

These kinds of statistics lead to talk of genetic predispositions toward all kinds of behavior including alcoholism, violence, drug taking, and crime. We begin to believe that we have no choice over who we are or how we behave – and this kind of thinking can lead to excuses for socially unacceptable or criminal behavior. Some defense attorneys have already attempted to use genetic predisposition in their clients’ favor.

Such scientific findings parallel the theological issue of predestination. Predestination suggests that our behaviors and actions are mapped out in advance and that, because of this mapping, our future salvation fixedly awaits. Behavioral genetics suggests that, not only our physical, but also our personality traits possess a genetic component over which we hold no sway. We can’t change what biological fate set down for us. Both predestination and behavioral genetics raise issues of control. If our behaviors or personalities are fixed in advance, do we lack the power to deliberate, to act freely, and to stand responsible for our actions?

Perhaps we should ask if we really fall this much at the mercy of our genes. If most personality traits are around 50 percent heritable, then 50 percent outside influence remains – from our environment, our parents, our peer group, and ourselves.

Recent research and practice supports this intuition. Psychologist Grazyna Kochanska’s long-term study of pre-schoolers suggests the development of conscience depends both on children’s natural approach to the world (which genetic inheritance governs) and on specific parental practices. Fearful children become conscientious if they receive gentle discipline based on encouragement rather than coercion, while fearless children ignore gentle discipline and only become conscientious when they share a co-operative, loving, and secure relationship specifically with their mother. “We can’t change the genes, but we can change the way genes express themselves. We can change behavior,” says psychiatrist Stanley Greenspan. Working with children and their parents, Greenspan re-routes youngsters’ genetic predispositions. He successfully prescribed gentle rocking to soothe an acutely fearful three year-old and imaginative play to develop the child’s assertiveness.

This aspect of behavioral genetics may shed some light on the dilemmas that predestination raises. Molecular biologist Dean Hamer draws an important distinction between temperament (what we’re born with) and character (what we learn). “One of the biggest myths is that something is genetic, therefore it is fixed. And of course this simply isn’t true,” he says. “All these genes do is give us a disposition one way or another. Whether we act on that is still very much a matter of free will or choice.” Consider how some of us arrive in this world with a genetic predilection for thrill seeking. Some fear nothing and will do anything – hang-gliding, parachuting, or bungee jumping. But no one can predict what thrill-seekers will make of their predilection. A thrill-seeker may become a fire fighter or a drug addict. Free choice enters here. We may inherit very broad-brush personality traits, but how we choose to mold those characteristics depends on us.

Perhaps, then, we should consider temperament the package that God foresees or foreordains – our genetic predestination. Not even God can predict how we will transform temperament into character. Since we can, in this sense, act freely, neither can God predict how well we will behave.

Genetic predisposition looks like a modern form of divine predestination. If it is, it is also a sophisticated form that allows us freely to work out our destiny in and from the cradle of the behaviors our genes predispose.

Further Reading

Dean Hamer and Peter Copeland. 1998. Living with our Genes. New York: Doubleday.

Lawrence Wright. 1997. Twins: Genes, Environment, and the Mystery of Human Identity. London: Weidenfeld and Nicholson.

To appear in Science & Spirit. Copyright © 2000 by Kevin Sharpe.

Comments and Responses:
"Predestination by Genes." Letter from Andrew Petto, 4 April 2000.
    Rejoinder from Kevin Sharpe.