Aside from the horrors committed during the Holocaust in its systematic killing of Jews and other Nazi prisoners of war, one of the most salient crimes against humanity was that of dehumanization. The war experiments committed by the Nazis, and the killing of people whom they did not see as "suitable" to be alive, are clear indications of two things: a) the horrific capacity of the human brain to compartmentalize even inhuman acts (that would be the Nazis) and, b) the fact that there are people who are physically able to commit these crimes "as told."
In Shirley Jackson's story "The Lottery" we see evidence of these two facts. First, the compartmentalization of inhumanity is evident in the villagers, who take the stoning tradition as a matter of fact. They talk about it, remember it, and even have a paltry historical background of it that they admit to not really knowing about in its entirety. Yet they have embraced this sadistic practice and consider it a part of their identity as a village.
The actual act of engaging in the stoning is another evidence of what Shirley Jackson may have wanted to reflect in her writing about society. By the time the story was written in June of 1948, three years after WWII was over, the world had already engaged in world wars twice. People were told to kill, and kill they did. In the same fashion, the villagers also kill one another every year, because that is what tradition tells them to do.
While knowledge of the Holocaust itself did not come to light until years later in its entire detail, it is clear that Shirley Jackson had a preoccupation with the human capacity for violence. Moreover, the social worry of whether a bigger or worse war would ever happen again, and of the consequences of such violence, certainly left many rattled as is evident in much of the literature of the period.