While many approaches to incarceration are aimed at rehabilitating a criminal to the degree that they can safely re-enter society, the life sentence without parole is a strictly punitive alternative to the death sentence. Just as the death sentences raise ethical concerns, experts have studied the effects of long-term incarceration on those imprisoned.
Prison is for all prisoners a life-altering experience. The prison environment is harsh and at times dangerous, leaving inmates with many atypical patterns of thinking and behaviour. The clinical terms "institutionalization" or "prisonization" identify the negative psychological impact experienced by inmates in a correctional facility. According to a study by Craig Haney at the University of California Santa Cruz, the normal psychological response to being deprived of privacy and freedom includes dependence on structures, hypervigilance, suspicion, isolation and damaged self esteem.
Some prisoners adapt to prison life by withdrawing socially. Inmates may experience symptoms that are similar to depression, or to patients with terminal diseases who close themselves off to relationships out of deep resignation to their fate. Others focus more on work and other activities rather than withdrawing into themselves. Studies suggest that where inmates decline socially with other inmates over decades, they maintain contact with outside relationships.
Studies have shown that prison takes a physical toll on inmates as well as emotional. Since inmates are denied conjugal rights, sexual deprivation is a concern. Many prisoners find they must fight for dominance in a social order based on homosexual sex which is often forcible, and can lead to the spread of infectious diseases. In rare instances, prisoners hopeless and fatigued from prison life suddenly die for reasons unexplained.
Long term prison sentences have been shown to increase hostility in inmates if for no other reason than the loss of autonomy. The strict rules and lifestyle that confines a prisoner's life govern every conceivable aspect that many non-incarcerated persons might take for granted: what to wear, what to eat and which tasks to perform. All of these components taken together are characteristic of the helpless state of childhood, and can be extremely frustrating for inmates, resulting in open hostility.