All in Our Genes?

If you have a craving for candy and cookies, it may be written in your genes. So said a team of geneticists who have discovered that obese people often have a less common form of a particular gene—the dopamine receptor gene. Nearly half the obese people studied had this unusual form of the gene. We already know that genes spell out our physical features, like height and hair color. But do genes govern our behavior as well? Some scientists seem to think so. The same team of researchers have also located a genetic basis for alcoholism and cocaine addiction. Roughly half the addicts studied had the gene. Other researchers are working feverishly to show that homosexuality is genetic. One study indicated a gene causing homosexual behavior may be located on a small stretch of DNA on the X-chromosome. Other researchers are asking whether there’s a genetic component to crime. The most ambitious geneticists hope to show that the human personality itself is determined by our genes. Francis Crick, co-discoverer of DNA, recently wrote a book called The Astonishing Hypothesis, subtitled The Scientific Search for the Soul. Crick claims that the entire human personality or soul— “your joys and sorrows, your memories and ambitions, your sense of personal identity”—can be reduced to the behavior of the molecules in your brain, acting at the behest of the genes. Language like this ought to raise a huge red flag for Christians. When Crick talks about the “soul,” he has left the realm of science far behind and is giving us his personal philosophy. He’s expressing his commitment to the philosophy of genetic determinism—that people are no more than walking DNA. But if we stick to sober scientific facts, they simply do not support these wild conjectures. Recall that in the study on addiction, only half the people addicted have the unusual form of the dopamine receptor gene—which means the rest got hooked without any genetic basis. On the other hand, some people who do have the gene succeed in resisting temptation. In other words, we’re not talking about genetic determinism but a genetic predisposition—a predisposition that can be resisted by our moral decisions. Dr. David Persing is a molecular genetics researcher and a Christian. The biblical teaching that all of nature is fallen includes our genetic heritage, Persing says. As a result, we all have inborn tendencies toward various forms of sinful behavior—whether it’s addiction, a sexual disorder, or a tendency to ruthlessness or cowardice. But this fact is no excuse for sin, Persing says. We still have room for making real moral choices. Everyone is dealt a different genetic hand in life, but we’re each responsible for how we play it. As Christians we need to stand against the philosophy of genetic determinism, which reduces people to pawns of their genes. The life-giving message of the Gospel is that despite our fallen nature, we can still respond to divine grace. We can still be governed by God, not by our genes.

04/29/96