1. The frequency of various antecedent familial experiences in the histories of 568 schizophrenics from the U. S. Navy was determined and compared with incidence data from the general population, a group of 100,000 Naval recruits, and, where applicable, to a previously studied group of 392 schizophrenics from the Elgin State Hospital.2. The factors investgiated were: (1) marked rejection and/ or overprotection by one or both parents; (2) bereavement by death or separation of one or both parents prior to the fifteenth year; (3) placement in the sibling hierarchy; (4) family size; and (5) religious affiliation.3. It was found that among this group, 50.3% came from homes in which there was severe rejection and/or overprotection by one or both parents. Severe rejection by one or both parents was by far the most frequently manifested attitude, 34% having been so rejected, while only 9% were overprotected by one or both parents. A rejecting father was the most frequently encountered pathological parental attitude.4. Of the entire group 41% had lost a father or mother by death, divorce, or separation before the age of 15 years, as compared with 11.4% of such loss among the generality of Navy men. Approximately 4 times as many of this schizophrenic group had been orphaned prior to their fifteenth year than in the general population. The loss of the father by death was predominant: 55% of the schizophrenic orphans had lost a father, 33% a mother, and 18% had lost both.5. As to the sibling position, 18% were oldest children, 26% youngest, 12% next-to-youngest, and 14% were only children. All other placements constituted 31%. Youngest children slightly, but definitely, predominated. Among the Naval group 25% were oldest children, 25% youngest, 9% only children, and all other placements constituted 34%. Possible implications of ultimate sibling placement on the development of the self are discussed.6. The average family size of members of the schizophrenic sample was 4.4 children per family. This compares with a national average of 2.2 per family. It is considered that large family membership may operate to produce specific stress situations; and mechanisms by which this might operate are described.7. Among the group, 51% were professed Protestants, 42% Catholics, 2% Hebrews, 2% other or none. It is not certain that religious membership per se played any decided role in the development of schizophrenic illness.8. Some of the implications of these data for identification theory and upon the genesis of schizophrenia are discussed.