The book covers important topics in the psychiatric genetics (PG) field. Many of these have been overlooked in mainstream accounts, and many contemporary PG researchers have omitted or whitewashed the eugenic and "racial hygiene" origins of the field. The author critically analyzes PG evidence in support of genetic claims which, given the lack of gene discoveries, are based mainly on the results of psychiatric twin and adoption studies. Given that the evidence in favor of genetic influences is much weaker than mainstream sources report, due to serious issues in twin and adoption research, the author points to environmental factors, including trauma, as the main causes of conditions such as schizophrenia.