What details support Winston’s assertion in 1984 that “the proles are human beings. We are not human”?

Perhaps worse than robbing the populace of material goods, the Party has robbed them of feelings and natural impulses such as love, compassion, and friendship. Everything the Party does robs Inner and Outer Party members of their natural feelings. The proles, however, being mainly ignored by the Party, have retained their natural sympathies. They are still human because they still love, create families, and enjoy intimacy with each other. Winston remembers regretfully the time when he coldly kicked a severed hand into the street and feels as if this is an inhuman act. He believes that the Party will find him and kill him but knows that, as long as he can hold onto his feelings, they cannot kill his spirit. “If the object,” he concludes, is not to stay alive “but to stay human, what difference did it ultimately make?” He believes he can choose to “stay human,” although the Party’s ultimate eradication of his humanity proves his belief false.