Inaccuracy and Bias in Textbooks Reporting Psychiatric Research: The Case of the Schizophrenia Adoption Studies

Mental health textbooks sometimes provide inaccurate information, typically supporting common beliefs in the field. Psychiatry and psychology textbooks' discussion of the schizophrenia adoption studies is examined. Particular attention is paid to the earlier studies, which helped pave the way for the current widespread acceptance of the importance of genetic factors influencing psychological trait differences. This article compares the accounts of 30 textbooks to the original studies they reviewed. Generally, problems with these textbooks' accounts include (1) the failure to critically assess the original researchers' methods and conclusions, (2) some textbooks' reliance on secondary sources, (3) the failure to discuss published critiques of the schizophrenia adoption studies, (4) inaccuracy in reporting the original findings, (5) the claim that studies finding nonsignificant results support the genetic position, and (6) a failure to discuss the potentially invalidating environmental confounds in the schizophrenia adoption studies (through the selective placement of adoptees). It is concluded that, in general, these textbooks have served to rubber-stamp mainstream psychiatry's questionable claims about the schizophrenia adoption studies at the expense of a thorough critical analysis.