And as long as mother & son or father & daughter, don''t procreates then it''s no harm done, from a biological standpoint. As adults it''s there right to do so, and the state legislation should not prohibit it. Adult Incestuous relationships is a natural and rightful as homosexuals. Father-Daughter Incest Book Description: Through an intensive clinical study of forty incest victims and numerous interviews with professionals in mental health, child protection, and law enforcement, Judith Herman develops a composite picture of the incestuous family.