Overall, the effects detected of time spent in prison and the quality of life before prison on response to imprisonment was small. A considerable proportion of the variation in adaptations was unaccounted for by the indigenous (prison environment) and imported factors that were studied along with others. Time spent in prison had a direct effect on prisoners’ participation in programs, their thoughts of needing control over their lives, their feelings of hopelessness, and their disciplinary infractions in prison. Prisoners’ quality of life before prison had a direct effect on their participation in programs, their feelings of happiness, and their prison infractions. Lastly, time spent in prison and quality of life before prison interacted to affect prisoners’ contact with their family and friends. There has always been great interest in how people adjust to prison life. The patterns of adaptation to imprisonment can have significant implications. The extent to which adaptations are influenced by the prison environment itself (indigenous) or influenced by the prisoners’ preprison characteristics (imported) has been a matter of considerable debate. This study investigated specific adaptations to imprisonment as a function of time spent in prison and quality of life before prison, with the goal of examining the relative and interactive explanatory power of these two influences. Data for the study consisted of responses on a self-administered survey completed by 712 prisoners. Tables, figure, and references