If the illness were dictated solely by genetic inheritance, the identical twin of a schizophrenic person would always be schizophrenic as well, because the two have the same genetic makeup.

• 如果这种病症全然是由基因遗传所主导，那麽同卵双胞胎之一得了精神分裂，另外一位也应该会发病，因为两人拥有相同的基因组成。