Jay Joseph, Psy.D., is a clinical psychologist practicing in the San Francisco Bay Area of California. Since 1998, his articles on genetic research in psychiatry and psychology have appeared in journals such as Developmental Review, The American Journal of Psychology; Genetic, Social, and General Psychology Monographs; Politics and the Life Sciences; The Journal of Mind and Behavior Psychiatric Quarterly; New Ideas in Psychology; and Ethical Human Sciences and Services. He is currently an Associate Editor of Ethical Human Sciences and Services, and an Assessing Editor of The Journal of Mind and Behavior.

Genetic factors are increasingly presented as an important influence on psychiatric disorders, personality, intelligence, and various types of socially unacceptable behavior - as if that were an unassailable fact, proven by...

Genetic factors are increasingly presented as an important influence on psychiatric disorders, personality, intelligence, and various types of socially unacceptable behavior - as if that were an unassailable fact, proven by research.

Jay Joseph's timely, challenging book provides a much-needed rebuttal of the evidence cited in support of genetic theories in psychiatry and psychology, which are based mainly on twin and adoption studies. He shows that, far from establishing the importance of genes, psychiatric genetic and behavior genetic research on twins and adoptees has been plagued by researcher bias, unsound methodology, and a reliance on erroneous theoretical assumptions. Furthermore, he discusses how this faulty research has been used to support the interests of those attempting to bolster conservative social and political agendas.

In 1925, when the eugenics movement’s influence was at its height and a belief in the overriding importance of genes was widespread, psychiatrist Abraham Myerson observed, “We often hear of hereditary talents, hereditary vices, and hereditary virtues, but whoever will critically examine the evidence will find that we have no proof of their existence.”1 The evidence of Myerson’s era consisted of family pedigrees, preconceived notions, and prejudice. Today it consists mainly of family studies, adoption studies, studies of twins reared together, studies of twins reared-apart, and molecular genetic research.

Although it is widely believed that the results of these investigations converge on the importance of genetics, I will argue in this book that conclusions in favor of genetics based on family, twin, and adoption studies are faulty. And as we will see in Chapter 10, molecular geneticists have failed to find postulated genes for the major psychiatric disorders. Thus, Myerson’s 1925 observation is more relevant to today’s evidence than is commonly believed.

In 1996, twin researcher Irving Gottesman wrote, “no educated person . . . can be oblivious to the fact we are in the midst of a genetic revolution.” He added that the younger generation of genetic researchers could hardly imagine “the uphill battle that had been fought for the past 45 years.” With what weapons was this “battle” fought? Gottesman identified the “old-fashioned strategies” of family, twin, and adoption studies. And he is correct that these methods helped pave the way for the ascendancy of the genetic position as articulated by the fields of behavior genetics and psychiatric genetics….