From Science, 1994: Time and time again, scientists have claimed that particular genes or chromosomal regions are associated with behavioral traits, only to withdraw their findings when they were not replicated. Joel] Gelernter, “it’s hard to come up with many” findings linking specific genes to complex human behaviors that have been replicated. All were announced with great fanfare; all were greeted unskeptically in the popular press; all are now in disrepute. The author of the lead article on genes and behavior in a special issue of Science speaks of the renewed scientific recognition of the importance of environment.
He notes the growing understanding that: . The same data that show the effects of genes, also point to the enormous influence of nongenetic factors. More Modest Claims to the Scientific Community Researchers’ public statements to the press are often grand and far-reaching. But when answering the scientific community, they speak much more cautiously. He replied: “Absolutely not. Our studies try to pinpoint the genetic factors. But in qualifying their findings, researchers often use language that will surely evade general understanding making statements that will continue to be avoided by the popular press, such as: . Sounds too complex to bother translating? This is actually a very important statement.
In layman’s terms, this means: It is not possible to know what the findings mean–if anything–since sexual orientation cannot possibly be inherited in the direct way eyecolor is. Thus, to their fellow scientists, the researchers have been honestly acknowledging the limitations of their research. However, the media doesn’t understand that message. Columnist Ann Landers, for example, tells her readers that “homosexuals are born, not made. Accurate Reporting Will Never Come in “Sound Bites” There are no “lite,” soundbite versions of behavioral genetics that are not fundamentally in error in one way or another. Nonetheless, if one grasps at least some of the basics, in simple form, it will be possible to see exactly why the current research into homosexuality means so littleand will continue to mean little, even should the quality of the research methods improveso long as it remains driven by political, rather than scientific objectives.
Understanding the Theory There are only two major principles that need to be carefully understood in order to see through the distortions of the recent research. They are as follows: 1. Heritable does not mean inherited. Genetics research which is truly meaningful will identify, and then focus on, only traits that are directly inherited. Almost every human characteristic is in significant measure heritable. But few human behavioral traits are directly inherited, in the manner of height, for example, or eye color. Inherited means “directly determined by genes,” with little or no way of preventing or modifying the trait through a change in the environment. How to “Prove” That Basketball-Players are Born that Way Suppose you are motivated to demonstratefor political reasons–that there is a basketball gene that makes people grow up to be basketball players.
You would use the same methods that have been used with homosexuality: (1) twin studies; (2) brain dissections; (3) gene “linkage” studies. The basic idea in twin studies is to show that the more genetically similar two people are, the more likely it is that they will share the trait you are studying. So you identify groups of twins in which at least one is a basketball player. You will probably find that if one identical twin is a basketball player, his twin brother is statistically more likely be one, too. You would need to create groups of different kinds of pairs to make further comparisons–one set of identical twin pairs, one set of nonidentical twin pairs, one set of sibling pairs, etc. Using the “concordance rate” (the percentage of pairs in which both twins are basketball players, or both are not), you would calculate a “heritability” rate.