QUEENSTOWN -- State troopers set up a roadblock outside the conference on crime and genetics yesterday, but they weren't needed. The weekend meeting, preceded by years of rancor and two hours of protests Saturday, ended amid unaccustomed calm.
In the end, about 100 scientists and other scholars even seemed to agree on one thing: There's no direct evidence that specific genetic mutations can make someone more likely to commit a violent crime, and such mutations may never be found.
But supporters hope such genes exist, and that one day murder and mayhem can be prevented with medical therapy. Critics, meanwhile, strongly doubt that such genes exist and say the search for them could have tragic consequences.
Genetic explanations for violence encourage "passive attitudes toward social justice and aggressive neglect of social problems," said Dorothy Nelkin, a New York University sociologist.
The research, foes warned, could lead to a new holocaust, or encourage a rebirth of the American eugenics movement, which in the early 20th century led to the forcible sterilization of thousands of poor people. Such studies, they charge, may fuel racist attitudes about African-Americans and Hispanics, who are arrested and jailed at far higher rates than whites.
Some scientists, meanwhile, scoffed at the notion that things as ill-defined as crime and violence could be traced to specific genes. The separate contributions of genes, prenatal development and the environment to complex behaviors, they said, might never be untangled.
Supporters of the research, such as Adrian Raine, a psychologist at the University of Southern California, acknowledged there were risks.
But, he said, it would be a "tragedy" if the hunt for genetic or other biological factors in violence turns up empty. "We will never, ever be able to understand violence," he said. "We will never be able to control violence.
"I don't want blood to be on my hands in the future by being part of creating a new holocaust or a new eugenics movement in this country," Dr. Raine said, adding that he viewed such a consequence as unlikely. On the other hand, he said, if critics succeed in stopping the research they might have "the blood on their hands" of innocent crime victims.
The National Institutes of Health spends about $2 million each year on research into potential biological causes for violence. Most of it is focused on such topics as the effect of nutrition programs and lead levels in the blood. None of it bears directly on genetic links to crime, said Susan D. Solomon, senior adviser for behavioral research at NIH.
Dr. Solomon, who attended the conference, said afterward she doubted that any proposed genetics-and-crime studies would get federal money.
"Genetics isn't the way people are going to want to go when they try to intervene in violence," she said. "I don't feel that anybody thinks there's a strong link."
But many biological studies have genetic implications.
"If you wanted to stop all research which could potentially lead to understanding behavior associated with crime, that would mean doing no research on many well-defined psychiatric disorders," said Dr. David Goldman, chief of the laboratory of neurogenetics at the National Institute of Alcohol Abuse and Alcoholism.