Final answer:
The statement that there is no genetic factor associated with schizophrenia is false. Genetic factors do contribute to the risk of developing schizophrenia, but environmental stressors are also important.
Step-by-step explanation:
The answer to the question regarding the association between genetics and schizophrenia is false. There is indeed a genetic factor associated with schizophrenia. Studies, such as the one by Tienari et al., suggest that there is a significant genetic component to the disease, as evidenced by a higher risk in adoptees whose biological mothers had schizophrenia compared to those whose mothers did not. However, the environment plays a crucial role as well. Adoptees with high genetic risk were most likely to develop schizophrenia if raised in disturbed home environments. This supports the idea that genetic vulnerability and environmental stress together contribute to the development of schizophrenia.