I think that society is responcible for a good part of what happens at the end of Book 1. Bigger feels extreamly uncomfortable hanging out with white Jan and Mary because he knows that he could be pulled over and beaten to a pulp at any given moment. When he drives home with Mary he has no idea what to do with her because she is so drunk she's gone. He decides to help her get up to her room even though he knows that society won't allow him to even touch a white woman, much less drag her to her bedroom. He gets lost in the moment and almost takes advantage of Mary when Mrs. Dalton comes in to check on her. Bigger stuffs the pillow in her face to make sure she is quiet, the fact that he is there is Bigger's fault, but society would probably kill him if he was caught and this is what makes him react in this way. His reaction may not have been as extreame if he wasn't afraid of being killed as a result. When he was thinking of ways to get rid of her body it was a combination of his and society's fault. Once again he would have been killed if found out, but if he was white than he probably would have faced prison instead. When humans, or any animals, are threatened with death they tend to go to more extreames than they would if they were threatened with life confinement. The burning and decapitation of the body was Bigger's responce, it wasn't society's fault. he could have done something a little less morbid, not that disposing of a corpse is a daily chore.