The most consistent thing many have done is to live down to expectations. The three to six months that most corrections departments budget for pre-release training aren't enough to correct lifetimes of bad habits. Teaching inmates to make good decisions takes practice, practice, practice, as Schriro states. It requires sufficient time - preferably years so that the rewards of good choices and consequences of bad ones imprint and gradually change behavior. And the more post-prison supervision is provided, the greater the chances for successful integration to the community, Petersilia reports.
Prisons are mostly about security and control.
That's necessarily still the norm, even as opportunities grow in areas such as work, addictions treatment, anger management, volunteer activities and education. It is tricky to ensure safety while giving inmates more scope to make decisions that matter to them. It's tricky also to link their choices to rewards or rebukes that matter to them. Relapses here occur most often in the first year. After that, ex-cons tend to do pretty well.