Americans are increasingly likely to attribute their own—and others'—behavior to innate biological causes. At best that may relieve guilt about behavior we want to change but can't. The quest for genetic explanations of why we do what we do more accurately reflects the desire for hard certainties about frightening societal problems than the true complexities of human affairs. Meanwhile, the revolution in thinking about genes has huge consequences for how we view ourselves.
Just about every week now, we read a newspaper headline about the genetic basis for breast cancer, homosexuality, intelligence, or obesity. In previous years, these stories were about the genes for alcoholism, schizophrenia, and manic-depression. Such news stories may lead us to believe us are being revolutionized by genetic discoveries. We may be on the verge of reversing and eliminating mental illness, for example. In addition, many believe, we can identify the causes of criminality, personality, and other basic human foibles and traits.
But these hopes, it turns out, are based on faulty assumptions about genes and behavior. Although genetic research wears the mantle of science, most of the headlines are more hype than reality. Many discoveries loudly touted to the public have been quietly refuted by further research. Other scientifically valid discoveries—like the gene for breast cancer—have nonetheless fallen short of initial claims.
Popular reactions to genetic claims can be greatly influenced by what is currently politically correct. Consider the hubbub over headlines about a genetic cause for homosexuality and by the book The Bell Curve, which suggested a substantial genetic basis for intelligence. Many thought the discovery of a "gay gene" proved that homosexuality is not a personal choice and should therefore not lead to social disapproval. The Bell Curve, on the other hand, was attacked for suggesting differences in IQ measured among the races are inherited.
The public is hard pressed to evaluate which traits are genetically inspired based on the validity of scientific research. In many cases, people are motivated to accept research claims by the hope of finding solutions for frightening problems, like breast cancer, that our society has failed to solve. At a personal level, people wonder about how much actual choice they have in their lives. Accepting genetic causes for their traits can relieve guilt about behavior they want to change, but can't.
These psychological forces influence how we view mental illnesses like schizophrenia and depression, social problems like criminality, and personal maladies like obesity and bulimia. All have grown unabated in the past few decades. Efforts made to combat them, at growing expense, have made little or no visible progress. The public wants to hear that science can help, while scientists want to prove that they have remedies for problems that eat away at our individual and social well-being.
Meanwhile, genetic claims are being made for a host of ordinary and abnormal behaviors, from addiction to shyness and even to political views and divorce. If who we are is determined from conception, then our efforts to change or to influence our children may be futile. There may also be no basis for insisting that people behave themselves and conform to laws. Thus, the revolution in thinking about genes has monumental consequences for how we view ourselves as human beings.
The Human Genome Project
Today scientists are mapping the entire genome—the DNA contained in the 23 human chromosomes. This enterprise is enormous. The chromosomes of each person contain 3 billion permutations of four chemical bases arrayed in two interlocking strands. This DNA may be divided into between 50,000 and 100,000 genes. But the same DNA can function in more than one gene, making the concept of individual genes something of a convenient fiction. The mystery of how these genes, and the chemistry underlying them, cause specific traits and diseases is a convoluted one.
The Human Genome Project has, and will continue to, advance our understanding of genes and suggest preventive and therapeutic strategies for many diseases. Some diseases, like Huntington's, have been linked to a single gene. But the search for single genes for complex human traits, like sexual orientation or antisocial behavior, or mental disorders like schizophrenia or depression, is seriously misguided.
Most claims linking emotional disorders and behaviors to genes are statistical in nature. For example, differences in the correlations in traits between identical twins (who inherit identical genes) and fraternal twins (who have half their genes in common) are examined with the goal of separating the role of environment from that of genes. But this goal is elusive. Research finds that identical twins are treated more alike than fraternal twins. These calculations are therefore insufficient for deciding that alcoholism or manic-depression is inherited, let alone television viewing, conservatism, and other basic, everyday traits for which such claims have been made.
The Myth of Mental Illness
In the late 1980s, genes for schizophrenia and manic-depression were identified with great fanfare by teams of geneticists. Both claims have now been definitively disproved. Yet, while the original announcements were heralded on TV news and front pages of newspapers around the country, most people are unaware of the refutations.
Tags:
behavior,
bell curve,
biological causes,
causes of criminality,
certainties,
depression,
DNA,
faulty assumptions,
gay gene,
gene,
genes and behavior,
genetic basis,
genetic cause,
genetic discoveries,
genetic research,
hubbub,
human affairs,
human foibles,
initial claims,
newspaper headline,
societal problems,
weight
