what process do the prisoners undergo after they pass the selection that degrades an dehumanize them?

At the barracks, veteran prisoners began to beat the new arrivals and told them to get undressed. The new prisoners threw their clothes into a huge pile. SS officers selected strong men who were taken to work in the crematories. The new arrivals were then taken to the barber, where all their body hair was shaved off. People began to greet friends and relatives and were filled with joy to see the people who were still alive. Eliezer tells a friend not to waste his energy crying, and he feels his fear vanishing and being replaced by "an inhuman weariness." Everyone feels numb and without any sort of emotion, and Eliezer describes them as "damned souls wandering the half-world." At five in the morning, the prisoners are then made to run naked to a different barracks where they are doused in petrol and hot water as disinfectant and then given clothes. At this point the prisoners have ceased to be men. Eliezer feels that the person he was has been destroyed and cannot believe that he has only been at the camp for a single night.