Inmates in male prison populations are guilty of much more severe offenses than female prisoners, negating the theory that female offenders are filtered more efficiently and therefore those who do go to prison are more criminal than their male counterparts. It is apparent that the differences between male and female correctional institutions are a product of the interaction between institutional characteristics. The generalization that female prisons are becoming more like male prisons is not entirely accurate. Instead, it would be better to say that male and female prisoner subcultures are continuing to follow different lines of development. Thus, the degree of gender differentiation in prisoner subcultures has not necessarily narrowed over time. It may have even slightly increased during the past decade. The only area in which the subcultures differ substantially, however, is with the existence of pseudofamilies, which exist only in female institutions. Female seudofamilies have not only parents and children but also grandparents, aunts, and cousins. The families incorporate the jealousy and role-playing found in traditional male-female relationships. They provide a meaningful social life and interpersonal support for the prisoners. In the 50 years since the first article on pseudofamilies appeared, no researcher has found any slight variation in the dozens of studies made on the phenomenon. Male prisoners never have anything even remotely resembling pseudofamilies. Deprivation of contact with members of the opposite sex of course means corresponding deprivation of heterosexual love. Despite a great deal of actual sexual contact, there is little homosexual love to be found in prisons for men; women seem to emphasize love over physical sex. Female prisoners will send love notes back and forth to each other without ever intending to engage in overt sexual behavior. Deprivation of sustained interpersonal support from family and friends is far more damaging to females than to males. Both subcultures solve the problem by creating substitute gender roles within the prisons. Black markets and underground economies exist in both subcultures. The male prisons, however, often have elaborate systems that make those of the female prisons look primitive. Both male and female inmates exhibit opposition to the prison staff in proportion to their criminality and experience with deprivation. A total of 22 references are provided.