The earliest evidence of the existence of the prisoner dates back to 8,000 BC from prehistoric graves in Lower Egypt. This evidence suggests that people from Libya enslaved a San-like tribe.

Some of the most extreme adverse effects suffered by prisoners appear to be caused by solitary confinement for long durations. When held in "Special Housing Units" (SHU), prisoners are subject to sensory deprivation and lack of social contact that can have a severe negative impact on their mental health.

A psychopathological condition identified as "SHU syndrome" has been observed among such prisoners. Symptoms are characterized as problems with concentration and memory, distortions of perception, and hallucinations. Most convicts suffering from SHU syndrome exhibit extreme generalized anxiety and panic disorder, with some suffering amnesia.

The State-Trait Anxiety Inventory (STAI) was developed to understand the mechanisms behind anxiety. State anxiety describes anxiety that takes place in a stressful situation while trait anxiety is the tendency of feeling anxious in many situations because of a set of beliefs that an individual has that threatens their well-being.

SHU syndrome is a term that was created by Psychiatrist Stuart Grassian to describe the six basic mechanisms that happen in a cognitive matter in prisoners that are in solitary confinements or supermax level cell prison. The six basic mechanisms that occur together are:
• Hyperresponsivity to External Stimuli
• Perceptual Distortions
• Illusions, and Hallucinations
• Panic Attacks
• Difficulties with Thinking
• Concentration and Memory
• Intrusive Obsessional Thoughts
• Overt Paranoia
Stuart Grassian proposed that the symptoms are unique and are not found in any other situation.

Long durations may lead to depression and changes in brain physiology. In the absence of a social context that is needed to validate perceptions of their environment, prisoners become highly malleable, abnormally sensitive, and exhibit increased vulnerability to the influence of those controlling their environment. Social connection and the support provided by social interaction are prerequisites to long-term social adjustment as a prisoner.

Prisoners exhibit the paradoxical effect of social withdrawal after long periods of solitary confinement. A shift takes place from a craving for greater social contact to a fear of it. They may grow lethargic and apathetic, and no longer be able to control their own conduct when released from solitary confinement. They can come to depend upon the prison structure to control and limit their conduct.

Long-term stays in solitary confinement can cause prisoners to develop clinical depression, and long-term impulse control disorder. Those with pre-existing mental illnesses are at a higher risk for developing psychiatric symptoms. So…

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The founding of ethnographic prison sociology as a discipline, from which most of the meaningful knowledge of prison life and culture stems, is commonly credited to the publication of two key texts: Donald Clemmer's The Prison Community, which was first published in 1940 and republished in 1958; and Gresham Sykes classic study The Society of Captives, which was also published in 1958. Clemmer's text, based on his study of 2,400 convicts over three years at the Menard Correctional Center where he worked as a clinical sociologist, propagated the notion of the existence of a distinct inmate culture and society with values and norms antithetical to both the prison authority and the wider society.

In this world, for Clemmer, these values, formalized as the "inmate code", provided behavioural precepts that unified prisoners and fostered antagonism to prison officers and the prison institution as a whole. The process whereby inmates acquired this set of values and behavioural guidelines as they adapted to prison life he termed "prisonization", which he defined as the "taking on, in a greater or lesser degree, the folkways, mores, customs and general culture of the penitentiary". However, while Clemmer argued that all prisoners experienced some degree of "prisonization" this was not a uniform process and factors such as the extent to which a prisoner involved himself in primary group relations in the prison and the degree to which he identified with the external society all had a considerable impact.

"Prisonization" as the inculcation of a convict culture was defined by identification with primary groups in prison, the use of prison slang and argot, the adoption of specified rituals and a hostility to prison authority in contrast to inmate solidarity and was asserted by Clemmer to create individuals who were acculturated into a criminal and deviant way of life that stymied all attempts to reform their behaviour.

Opposed to these theories, several European sociologists have shown that inmates were often fragmented and the links they have with society are often stronger than those forged in prison, particularly through the action of work on time perception
The convict code was theorized as a set of tacit behavioural norms which exercised a pervasive impact on the conduct of prisoners. Competency in following the routines demanded by the code partly determined the inmate's identity as a convict. As a set of values and behavioural guidelines, the convict code referred to the behaviour of inmates in antagonising staff members and to the mutual solidarity between inmates as well as the tendency to the non-disclosure to prison authorities of prisoner activities and to resistance to rehabilitation programmer. Thus, it was seen as providing an expression a…

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