Scientists' Debate: Nature or Nurture? Digging for the Roots of Human Behavior
William Allen Post-Dispatch Science, St Louis Post-Dispatch (MO)
A RECENT REPORT THAT humans are genetically programmed for infidelity is a simplistic leap of logic, local scientists say.
"When people say we're born to be unfaithful, it's like saying we're born to be gamblers, drug addicts or alcoholics," said Dr. C. Robert Cloninger, a psychiatrist at Washington University School of Medicine.
"It's just not that simple," said Cloninger, who studies the genetic basis of personality. He reflected the view of several scientists who study the relationship of genes and behavior.
At issue is a long-standing debate among scientists about whether genetic makeup or lifetime experiences - nature or nurture - most shapes personality and character.
The debate has revived in recent years as new technology made it possible for scientists to begin mapping out the functions of specific genes in the human genetic blueprint carried by the DNA in our chromosomes.
As they discover specific genes for physical traits and for such maladies as Huntington's disease, they're also finding tantalizing signs that genes influence our behavior much more than previously thought.
But finding which genes lead to which behaviors is incredibly hard. That's partly because many genes may be involved in any given type of behavior - from simple cheerfulness to more complicated traits like infidelity, criminality and even a taste for Scotch and soda.
Still less clear are the enormously complex interactions between the genetic code - which dictates the basic structure of circuits in the brain - and the life experiences that further shape those circuits.
Researchers believe that a person's genetic blueprint instructs the developing body how to build the brain's basic circuits. The billions of circuits in that three-pound mass connect and fall apart according to the person's experiences - from touching a hot stove to reading a book. Out of those circuits come character and personality.
That's why a person's genetic makeup and environment are inextricably linked, scientists say.
"The more we learn, the more we see that it is not at all an either-or situation," said Dr. Judith Miles, who leads a study of genetics and autism at the University of Missouri School of Medicine in Columbia.
Said Washington University's Dr. Theodore Reich, who helps lead a national study of genetics and alcoholism: "We're forced to study the full complexity of it." The Keeping Of Harems
The intriguing report on infidelity came last month in a Time magazine essay by writer Robert Wright, in which he adapted arguments from his soon-to-be-published book, "The Moral Animal: Evolutionary Psychology and Everyday Life. …