Klein and Horwitz studied eighty patients in whom various types of paranoid pictures were encountered. Psychodynamic factors were investigated, with special reference to the concept that homosexual conflicts are basic in these disorders. The patients showed widely varying types of character structure. Insecurity in family backgrounds, instability in the face of frustration, and painful sexual experiences were prevalent in the histories. While over and latent homosexual tendencies were prominent in some cases, in others there was a definite absence of any material which would support a supposition that homosexual problems were a factor. Moreover, the authors are of the opinion that homosexual anxieties, when they do occur, may be 'an expression of failure, blow to pride, or general distrust of acceptance. These fears did not, of necessity, represent homosexual strivings.' Klein and Horwitz conclude that 'if the relationship of homosexuality to the paranoid mechanism is assumed to be invariable, other important considerations will be neglected'.