Abstract

I begin by examining how genetics drivesschizophrenia research, and raise both familiar andrelatively novel criticisms of the evidence putativelysupporting the genetic basis of schizophrenia. Inparticular, I call attention to a set of concernsabout the effects of placentation on concordance ratesof schizophrenia in monozygotic twins, which furtherweakens the case for schizophrenia''s so-called stronggenetic component. I then underscore two criticalpoints. First, I emphasize the importance of takingseriously considerations about the complexity of bothontogenesis and the development of hereditarydiseases. The recognition of developmentalconstraints and supports is crucial, for attention todevelopment exposes the naivete of too many models ofgene action in the aetiology of disease. Secondly, Iattend to those schizophreniologists who ignoremethodological criticisms and thus presume a geneticbasis for schizophrenia, and then seek the schizophrenic genotype lacking an adequatephenotype. In response I attempt to demonstrate thenecessity of a sustained effort at characterizing thephenotype of schizophrenia as an enabling conditionfor the whole enterprise of psychiatric genetics – andfor psychiatry itself. Without the organism-levelphenotype, research at the level of genes will remainunproductive – assuming of course that research at thegenetic level is appropriate at all.