New Tools for an Old Problem
Human behavior is the most complex and difficult problem ever attacked by geneticists, and it is likely to resist their best efforts for a full explanation for many years to come. In fact, it is quite likely that classical genetics would never be able to solve the most puzzling problems in behavioral genetics. This difficulty in understanding human behavior arises for several reasons. The first major problem for the behavioral geneticist is that human behavior is far more complicated than the simple physical traits that Mendel was able to study in his pea plants. When Mendel did his breeding experiments he could look at a pea seed and easily determine whether that seed was smooth or wrinkly, but human behavioral options cannot be so easily dichotomized. The second major problem is that, unlike most of the research for which classical genetics is best suited, human behavior does not involve one or a few genes. Instead, human behavior is determined by a large number of genes, each of which probably has a small effect, and there may even be many different combinations of genes that result in the same behavior. The last major problem for the behavioral geneticist is that the environment can have a profound effect on behavior, so that a genetic effect can be either accentuated or blunted by the environment.22
Given all of these major problems, it is a good thing that modern behavioral geneticists have at their disposal a range of new tools that could scarcely have been imagined even a decade ago. These new tools of molecular genetics will be described here, from the standpoint of both their strengths and their
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Publication information: Book title: DNA and Destiny:Nature and Nurture in Human Behavior. Contributors: R. Grant Steen - Author. Publisher: Plenum Press. Place of publication: New York. Publication year: 1996. Page number: 63.