The author seeks, through statistical studies, to achieve an understanding of antecedent factors in the development of schizophrenia. He is impressed particularly by the high percentage (four times that in the general population) of loss of one or both parents before the age of fifteen. Somewhat surprisingly, loss of the father seems to be of even greater significance for both sexes than loss of the mother. The age of orphanhood before fifteen makes little apparent difference. The author speculates about the meaning of these findings.