The Gene Illusion (2004)

The Gene Illusion: Genetic Research in Psychiatry and Psychology Under the Microscope

Algora Publishing, 2004. Available from $26.95

Chapter-By-Chapter Summary of The Gene Illusion (PDF)

What are the forces shaping who we are, how we live, and how we behave? Are we shaped primarily by our environment, or by our genes? These very old questions form the basis of the “nature-nurture” debate. Increasingly, we are told that research has confirmed the importance of genetic factors influencing psychiatric disorders, personality, intelligence, criminality, and so forth. 

Jay Joseph’s timely, challenging book provides a much needed critical appraisal of the evidence cited in support of genetic theories in psychiatry and psychology. His book shows that, far from establishing the importance of genes, family, twin and adoption research has been plagued by researcher bias, unsound methodology, and a reliance on unsupported theoretical assumptions. Historically speaking, in Chapter Two he shows how this greatly flawed body of research has been used to support conservative social agendas and eugenics. This chapter contains the only in-depth critical review of twin research history ever published.

Much of the alleged scientific evidence put forward in support of genetic theories has been produced by the fields of behavior genetics and psychiatric genetics. It has been delivered to the public by the popular media, as well as by the authors of several popular books. These popular accounts typically promote the claims of the original researchers uncritically, and frequently contain errors and misrepresentations.

Studies of twins (both reared-together and reared-apart) have been put forward as providing conclusive evidence in support of genetic influences on psychological traits such as intelligence and personality. The reared-apart twin studies performed by researchers at the University of Minnesota have received a substantial amount of media attention, including stories of individual pairs of ostensibly reared-apart identical twins who, it was claimed, displayed remarkable similarities upon being reunited. Joseph shows, however, that both systematic reared-apart twin studies and stories about individual pairs provide little (if any) evidence in support of genetic influences on human psychological trait differences.

Schizophrenia is the most studied, and at the same time the most feared and misunderstood, of all psychiatric disorders. Joseph devotes two chapters to problems with genetic research in this area. In Chapter Seven he reviews schizophrenia adoption research, which includes the frequently cited Danish-American and Finnish investigations. Another chapter looks at the “genetics of criminal behavior” topic. Genetic theories in this area have been making a comeback in recent years. Additional chapters look into the genetics of IQ (including alleged racial differences in intelligence), the heritability concept, and molecular genetic research.

The bleak view of humans and their future put forward by the proponents of genetic determinism is based largely on the faulty research Joseph reviews in detail in this book. He concludes that there is little evidence (1) that disordered genes underlie psychiatric disorders such as schizophrenia, and (2) that genetic factors play an important role in explaining behavioral and psychological trait differences among humans.

The Gene Illusion is a groundbreaking work, and is essential reading for those seeking an alternative to the increasingly popular, yet mistaken view that “genes are destiny.”

Table of Contents

CHAPTER 1: Introduction
CHAPTER 2: Twin Research: Misunderstanding Twins, from Galton to the 21st Century
CHAPTER 3: The Twin Method: An Environmentally Confounded Research Method
CHAPTER 4: A Critique of Studies of Twins Reared Apart
CHAPTER 5: The Heritability Concept: A Measure of Inheritance or Inherently Misleading?
CHAPTER 6: The Genetics of Schizophrenia I: Overview
CHAPTER 7: The Genetics of Schizophrenia II: Adoption Studies
CHAPTER 8: Is Criminal Behavior in the Genes? A Critical Review of Twin and Adoption Studies of Criminal and Antisocial Behavior
CHAPTER 9: Genetics and IQ
CHAPTER 10: Molecular Genetic Studies in Psychiatry and Psychology: An Exercise in Futility?
CHAPTER 11: Where Do We Go From Here?