Piliavin et al (1969)
Piliavin et al (1969) is a classic studying of bystanderism vs helping behavior. The study may be used to explain factors that influence bystanderism, as well as a question on approaches to research or ethical considerations in the study of human relationships. You can see the original study here. Piliavin's classic study is based on his Arousal Cost Reward Model of helping. According to this model, we are motivated...