Danger in Linking Genetics to Criminal Behavior

by Tony Fitzpatrick

Social problems of the poor get explained away as 'genetic'	ST. LOUIS -- If criminal behavior is indeed due to a genetic predisposition toward violence or aggression, then behavioral scientists are overlooking some fertile research possibilities, says a biologist at Washington University in St. Louis. "For example, I've never seen a behavioral genetics study linking corporate embezzlement and genetics, or a single one about violent police behavior and genetics, nor one about genetic predispositions toward violence in the military," says Garland E. Allen, Ph.D., also a historian of science whose specialty is the eugenics movement in the United States and Europe from 1900 to 1940. "It's always social problems of the poor working class that get explained away as 'genetically' derived and in need of a scientific answer. But the genetic answer to social problems always has been used against people to blame them rather than social circumstances for their problems. And the so-called scientific answers to criminality today are no more clear-cut, though certainly more insidious, than they were earlier in the century."
A number of government genetics programs planned for study of violent or "anti-social" behavior	Allen presented a paper, "The Biological Basis of Crime: An Historical and Methodological Study," Sept. 23, 1995, at a National Institutes of Health (NIH)-funded conference. The conference explored the relevance of conducting research that linked genetics to criminal behavior. The funding came from an NIH program that examines the ethical and legal issues generated by the Human Genome Project. The conference, which had been canceled two years ago because of its incendiary nature, drew psychologists, biologists, sociologists, historians and neurobiologists into a fray that is certain to last for years to come. Because there are a number of government programs, including ones sponsored by NIH and the Centers for Disease Control (CDC), already in the planning stages for studies of genetics of violent or "anti-social" behavior, opponents and proponents of such research have lots at stake in the discussion. For three days, participants discussed and debated whether criminality is a heritable trait; whether genetic markers may be used to predict a predisposition toward violence; whether links can be drawn between low levels of the brain hormone serotonin and violent behavior; and whether studies of identical twins reared apart can shed any meaningful light on the significance of nature versus nurture. History shows that every time scientists try to explain social problems by simplistic biological models the outcome is a disaster, Allen says. He refers to the eugenics movement, which claimed that many social, personality and mental traits were hereditary. He says it was eugenic thought that led to concerns for the "burden of the poor" and "national efficiency" in Depression-era America and Germany. National efficiency was based on the claim that genetically "deficient" people drained the economies of industrious countries; therefore, such people were burdens best eliminated from the gene pool. He points to compulsory sterilization laws during the '20s and '30s in the United States that led to more than 20,000 sterilizations of both men and women by 1935 (over 60,000 by the 1960s); the Johnson Act of 1924, which restricted immigrants of "inferior biological stock" from central European and Mediterranean countries; and World War II and the Holocaust. All of the laws, designed to reduce crime and other persistent social problems such as pauperism, manic depression and prostitution, were made more palatable because they could be claimed to represent the cutting-edge science of their day, Allen says.
Books such as "The Bell Curve" lead the public to believe that genes are responsible	In his paper, he draws a parallel between the early 20th-century approach to social problems exemplified by Charles B. Davenport, an American geneticist and early proponent of eugenics, and a number of prominent researchers today. Davenport classified problems such as feeblemindedness, unemployment, alcoholism, prostitution, unruliness, nomadism and even thalassophilia -- love of the sea -- as inherited traits. Davenport's 1919 book, Naval Officers: Their Heredity and Development, argued that love of the sea is a sex-linked recessive gene, passing from mothers to half of their sons. More than 75 years later, there have been scores of publications seeking to establish genetic links to such personality traits and social behaviors as depression, alcoholism, shyness, homosexuality, risk-taking, "religiosity," TV-watching habits, impulsivity and, among the hottest of the decade, criminality and violence. In his paper, Allen analyzes concepts and methods of behavior genetics research, the economic and political forces driving such research, and the history of linking genetics and behavior in the 20th century. He noted that popular interpretations of recent books such as "The Bell Curve," by Richard Herrnstein and Charles Murray (1994), and "Crime and Human Nature," by Herrnstein and James Q. Wilson (1985), lead the public to believe that a gene or genes are responsible for specific social behaviors and personality traits. Combined with media hype surrounding the Human Genome Project as the definitive code to human life and neurosciences advances during the "decade of the brain," Allen claims the public believes science is closing in on answers to pervasive and persistent social problems, like crime in the streets. "People talk of relocating, changing jobs and moving out of urban areas to avoid what seems like an unsolvable, and growing, social menace," says Allen. "Such an atmosphere has provided an ever more fertile ground for claims that science can finally begin to provide answers that traditionally have been the province of the social sciences, and which the social sciences have failed to solve. "But genetic and/or neurogenetic explanations of criminal or violent behavior are seriously flawed by any canons of modern scientific research. They are flawed both conceptually -- they ask the wrong questions in the wrong ways -- and methodologically -- in their methods of data collection and the conclusions that are drawn. Very few of the studies delve into actual biological parameters. They simply trace histories, behavior and statistics. Most amazingly, almost none of the studies are performed by people with a formal background in genetics. They are almost all psychologists and psychiatrists."
Scientists are currently trying to link an enzyme with impulsivity and aggressive behavior	Highlighting numerous studies from the 19th century to 1994, Allen points out various recurrent methodological flaws: Subjective and vague definitions of the trait (phenotype) for which the supposed heredity is being studied (for example, unlike clearly defined traits such as blood type, height or eye color, the trait, "antisocial personality disorder" has received five different standard definitions in 20 years, meaning experts constantly disagree over its definition); Misuse of data from twin and adoption studies (in many such studies, researchers know little if anything about specific environmental conditions to which the twins or adoptees are exposed) Futile search for biological markers (from 19th-century cranial, shoulder, ear and nose measurements to 20th- century classifications of body types and measurements of hormone levels, no investigator has found an undeniable biological marker for criminal behavior) Faulty use of statistical concepts or procedures (lack of proper control groups, or faulty interpretation of statistical methods of heritability) Recently, biological markers, such as changes in the enzyme monoamine oxidase A in the central nervous system, have been touted as links to impulsivity and aggressive behavior. Because genes are known to produce enzymes, such sophisticated findings, made available by rapid developments in neurochemistry, should make the heritability of criminality more clear-cut. But Allen points out there are no biological correlates that can be associated with aggressive or criminal behavior while also ruling out other causes. "Similar changes in brain hormones or other enzymes are found in many mental and physical disorders -- for example, depression," he says. "The search for unique and consistent biological markers for criminality have been attempted from the 19th century to the present without any success. After all, is it possible to find an enzyme that makes you have a propensity to steal?" Instead, he says, behavioral genetics studies of criminality rely almost exclusively on description of phenotypes, or traits. "It is this kind of misuse of data -- false representation, one might say -- that has characterized this sort of work for over a century," Allen says. "The enormous difficulty involved in obtaining significant data that in any rigorous way can separate the effects of heredity from environment as causes of complex human behavior ought to make anyone immediately suspicious of strong claims about 'the gene for' or 'a significant genetic component to' a specific behavior. Whether measuring cranial index in the 19th century, IQ scores or serotonin levels in the 20th, over the years genetic determinist theories have continually failed to withstand close scrutiny. It is significant that every one of such theories in the past ultimately has been rejected or withdrawn."
	Science today, as in the eugenic period of the '20s and '30s, is in peril of becoming a pawn for instigating severe and long-lasting social policies, Allen asserts. "If undesirable behavior is believed to be due to a 'bad gene,'" he explains, "three strikes and you're out sounds like a more acceptable judicial policy. "When distinguished federal agencies such as NIH, the National Institute of Mental Health and the National Institute of Alcohol Abuse and Alcoholism invite applications to study the genetics of alcoholism, criminality or violence, scientists today are as vulnerable as their counterparts 60 years ago to contributing to social policies with potentially perverse results. The 'bottom line' mentality is not far removed from arguments of national efficiency and the 'burden of the poor' advanced in both the United States and Nazi Germany in the 1930s."

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