Secure confinement to eliminate the danger a prisoner might present to another need not require social and sensory isolation. That is purely punitive and futile at best, contributory at worst.
I don't disagree on the sensory isolation, but I think one of the reasons for social isolation is problem inmates who antagonize and provoke other inmates.
Sure you could physically isolate inmates, but allow them to communicate, but that would be like keeping two roosters together separated by chicken wire; they'd be at each other constantly with verbal threats, etc. Doesn't sound that much better.
