Since I have not read the first one, I could only speculate that the people who end up helping realize that nobody else is going to do anything to help, which breaks them out of the effect and they end up helping more.yEd graphs: https://www.yworks.com/products/yed
TAPs (Trigger Action Plans): https://www.lesswrong.com/posts/vE7Z2JTDo5BHsCp4T/instrumental-rationality-4-2-creating-habits
Since I have not read the first one, I could only speculate that the people who end up helping realize that nobody else is going to do anything to help, which breaks them out of the effect and they end up helping more.
yEd graphs: https://www.yworks.com/products/yed
TAPs (Trigger Action Plans): https://www.lesswrong.com/posts/vE7Z2JTDo5BHsCp4T/instrumental-rationality-4-2-creating-habits