Thursday, May 01, 2008

What Implications Does Behavioral Genetics Research Have For Society?

Researchers in the field of behavioral genetics have asserted claims for a genetic basis of numerous physical behaviors, including homosexuality, aggression, impulsivity, and nurturing. A growing scientific and popular focus on genes and behavior has contributed to a resurgence of behavioral genetic determinism—the belief that genetics is the major factor in determining behavior.
Are behaviors inbred, written indelibly in our genes as immutable biological imperatives, or is the environment more important in shaping our thoughts and actions? Such questions cycle through society repeatedly, forming the public nexus of the "nature vs. nurture controversy," a strange locution to biologists, who recognize that behaviors exist only in the context of environmental influence. Nonetheless, the debate flares anew every few years, reigniting in response to genetic analyses of traits such as intelligence, criminality, or homosexuality, characteristics freighted with social, political, and legal meaning.
What social consequences would genetic diagnoses of such traits as intelligence, criminality, or homosexuality have on society? What effect would the discovery of a behavioral trait associated with increased criminal activity have on our legal system? If we find a "gay gene," will it mean greater or lesser tolerance? Will it lead to proposals that those affected by the "disorder" should undergo treatment to be "cured" and that measures should be taken to prevent the birth of other individuals so afflicted?
There are several scientific obstacles to correlating genotype (an individual's genetic endowment) and behavior. One problem is in defining a specific endpoint that characterizes a condition, be it schizophrenia or intelligence. Another problem is in identifying and excluding other possible causes of the condition, thereby permitting a determination of the significance of a supposed correlation. Much current research on genes and behavior also engenders very strong feelings because of the potential social and political consequences of accepting these supposed truths. Thus, more than any other aspect of genetics, discoveries in behavioral genetics should not be viewed as irrefutable until there has been substantial scientific corroboration.
How do genes influence behavior?
No single gene determines a particular behavior. Behaviors are complex traits involving multiple genes that are affected by a variety of other factors. This fact often gets overlooked in media reports hyping scientific breakthroughs on gene function, and, unfortunately, this can be very misleading to the public.
For example, a study published in 1999 claimed that overexpression of a particular gene in mice led to enhanced learning capacity. The popular press referred to this gene as "the learning gene" or the "smart gene." What the press didn't mention was that the learning enhancements observed in this study were short-term, lasting only a few hours to a few days in some cases.

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