Exactly what in the story makes Jackson's attitude towards the lottery clear to readers in "The Lottery"?
The citizens'--even the children's--predilection for violence in the narrative of "The Lottery" suggests Shirley Jackson's condemnation of the natural propensity for violence that is present in human nature.
This natural inclination for violence underlies much of the action and dialogue in Jackson's story, at first subtly and then very overtly in the end. As early as the second paragraph, the narrator describes Bobby Martin as having "already stuffed his pockets full of stones," an observation that acts as foreshadowing of the violence to come. Further, that a laughing Bobby runs back to the pile of stones when the children are called to stand with their families indicates his strong penchant for violence as he wishes to assure that he has plenty of stones to throw at the victim.
This annual ritual has been in existence for decades although most of the citizens have forgotten why it was started. Only Old Man Warner suggests its purpose (creating a scapegoat to ensure good crops), but he blindly holds to its tradition. The other members of the community do not seem concerned with the purpose; instead, they mindlessly follow it, or they actually enjoy the sadistic nature of the custom. That Mrs. Delacroix delights in the violence is evident in her quick dismissal of her friendship for Tessie Hutchinson when Tessie's lot is cast. Mrs. Delacroix
...selected a stone so large she had to pick it up with both hands and turned to Mrs. Dunbar. "Come on," she said. "Hurry up."
Even when Mrs. Hutchinson cries that "it ain't fair, it isn't right," the sadistic nature of the villagers prevails and they satisfy their natural proclivity for violence: "Mrs. Hutchinson screamed, and then they were upon her."
Because Jackson provides repeated instances in which children and adults of all ages choose the sadistic ritual with its opportunity for violence instead of more civilized behavior, the author's attitude becomes clear as she castigates the innate cruelty of man by pointing to the inherent proclivity of man for violence in her story "The Lottery."
I think that recognizing the time period in which Jackson writes her short story is critical. On one hand, Jackson is writing in the time period in which she has seen the Nazis, the Soviet brand of Communism taking over, as well as the rise of McCarthyism on the domestic realm. Jackson is extremely aware of how the community can terrorize the individual. These historical events indicated this to her and was mindful of this in her writing. In the short story, it is this dimension that is evident. The stacking of stones by the children in the beginning, as well as the small and timid voices that bring about the idea of wishing for change, silenced by the voice of Old Man Warner who affirms tradition. The fact that Mrs. Delacroix, Tessie's closest friend, runs to find the biggest rock to throw when Tessie's name is pulled. Consider the ending of the story when the "semi- circle" envelops Tessie, as well. This is a symbolic image of how Jackson sees "the lottery" as the terror of the community against the rights of the individual. This image of the lone voice standing in the center of an encroaching semi- circle is a powerful one, and one that conveys Jackson's ultimate belief of how she sees the lottery.