ABSTRACT
A standard textbook in general genetics is that by A. M. Srb and R. D. Owen. A fundamental principle of genetics is that the phenotype is the result of the interaction of the genotype with the environment. A parent might transmit a gene predisposing to psychopathology, but at the same time also provides the relational environment with which the gene interacts to produce the phenotype. D. Rosenthal presents in modern form the debate over the organic versus the psychogenic origin of psychosis that characterised nineteenth century German psychiatry and was present in C. G. Jung’s 1907 monograph on dementia praecox. Concerning psychopathy, the common occurrence of psychopaths in the families of schizophrenics has been observed. In adoption studies, environmental factors are separated from genetic factors. There is the more general problem of the biological unity of the schizophrenic spectrum disorders and of the specificity of the schizophrenic genotype with regard to other functional disorders.
