Is Crime in the Genes? A Critical Review of Twin and Adoption Studies of Criminality and Antisocial Behavior Author(s): Jay Joseph Source: The Journal of Mind and Behavior, Spring 2001, Vol. 22, No. 2 (Spring 2001), pp. 179-218 Published by: Institute of Mind and Behavior, Inc. Stable URL: https://www.jstor.org/stable/43853952 JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at https://about.jstor.org/terms is collaborating with JSTOR to digitize, preserve and extend access to The Journal of Mind and Behavior JSTOR
179 @2001 The Institute of Mind and Behavior, Inc. The Journal of Mind and Behavior Spring 2001, Volume 22, Number 2 Pages 179-218 ISSN 0271-0137 Is Crime in the Genes? A Critical Review of Twin and Adoption Studies of Criminality and Antisocial Behavior Jay Joseph La Familia Counseling Service This paper performs a critical review of twin and adoption studies looking at possible genetic factors in criminal and antisocial behavior. While most modern researchers acknowledge that family studies are unable to separate possible genetic and environ- mental influences, it is argued here that twin studies are similarly unable to disentan- gle these influences. The twin method of monozygotic-dizygotic comparison is predicated on the assumption that both types of twins share equal environments, and it is argued here that this assumption is false. Adoption studies have been promoted as a better way of separating genetic and environmental influences. However, there is good reason to believe that adoption studies of criminal and antisocial behavior were confounded by selective placement factors. In addition, these studies suffered from bias and serious methodological errors. In spite of these problems, no adoption researcher claimed to have found evidence of a genetic predisposition for violent crime. It is con- cluded that the weight of the evidence from family, twin, and adoption studies does not support a genetic basis for any type of criminal or antisocial behavior. The histori- cal background of genetic theories of criminality is also discussed. The debate over the causes of crime is an old one. The potential for criminal behavior has been viewed by some as being stamped on people at birth for rea- sons of heredity, while others have maintained that "criminals are made, not born." Still others have taken an interactionist stance, holding that both genes and environment are important. This paper focuses on twin and adoption stud- ies of criminal, "antisocial," and "psychopathic" behavior. Topics beyond the scope of this paper include the "XXY" controversy of the 1960s and 1970s, studies linking abnormal behavior with specific genes (e.g., Brunner, Nelen, Breakefield, Ropers, and van Oost, 1993), and studies looking at possible bio- logical components of criminality. Although conflated in the minds of many, I thank