In parshas Ki Tavo there is much talk in the curse section about parents eating their own children, G-d forbid. We understand this came into fruition in the time of the first Temple's destruction. Question is: How is this possible for Jewish people? Even in the worst of situations there are countless stories of the incredible selflessness, and Chasidus explains that this is because of the G-dly Soul in every one of us.
I personally know someone who recalls that during the holocaust her mother would get a single crust of bread per day and would break it into prices for her children to eat while the mother would not eat any of it. We are known for rising up against physical things especially in the most difficult of situations. How do we understand the Torah setting this as a consequence?
Further Rashi comments, "because they will be besieging the city and there will be distress there - the oppression of hunger." So we are talking about something within the bounds of nature - not a Divinely inspired sense of selfishness coming on the people.