Real life application from WW2 can show frustration can be a casual factor in mass killings
Real world application
Staub believes that mass killings are often rooted in frustrations surrounding economic or social difficulties and frustration leading to aggression is directed at an innocent group.
Real world application
During WW2 Hitler and the Nazi blamed Jews for not contributing to German society and economics and so they were the scape groups or targets during WW2. Although ordinary Germans were not directly involved for subsequent murder’s some historians like Goldhagen have argued that they condoned the violence so German people believed at some level the propaganda to be true and so allowed it to happen.
Real world application of frustration shows that widespread frustration particularly when powered by propaganda can have violent consequences for innocent groups.