Presented in the paper is the hypothesis that father-daughter incest may be seen as a family maintenance device when the mother abdicates her sexual role and the father turns to his daughter to fulfill his sexual needs rather than going outside the family. Data from subcultures in Sweden, Japan, and America is cited. Female sex role development is described, and the daughter's willingness to participate in the incestuous relationship is seen to be an outgrowth of her sex role conditioning and self-esteem. It is suggested that the incestuous family conforms to the definition of a subculture. (CL)