In the movie, they alluded to the fact that Jerry's mother also heard voices, or as she called them, "angels." We can see that the cause of Jerry's schizophrenia may have had more to do with genetics. Research has shown that there is no single gene responsible for schizophrenia, but that different genetic combinations produce greater susceptibility. Family studies were also conducted in Berlin in 1938 (which is a coincidence since Jerry's family was from Berlin) and showed that parents with severe schizophrenia influenced the likelihood of their children developing it. It does not matter whether the parent had been diagnosed with specific schizophrenia; children were more sensitive to the general predisposition of