Regarding genetic factors in schizophrenia, which of the following statements is false?
1) When one identical twin has schizophrenia, the other twin has a 45% chance of developing the disorder.
2) Schizophrenia tends to run in families and has a strong genetic component.
3) Certain genes have been identified that are associated with an increased risk of developing schizophrenia.
4) Environmental factors, such as exposure to viruses or malnutrition during pregnancy, can also contribute to the development of schizophrenia.