Final answer:
The best explanation for why no one helped Eleanor for nearly an hour is diffusion of responsibility, where individuals feel less need to act because they assume others will intervene.
Step-by-step explanation:
The scenario presented best illustrates the concept known as diffusion of responsibility. This is a psychological phenomenon where each bystander's sense of personal responsibility is diminished by the presence of other witnesses. In other words, individuals in a group are less likely to offer help to a person in distress because they believe someone else will take action. Researchers Latané and Darley, who studied the bystander effect, have shown that the greater the number of bystanders, the less likely any one person is to intervene. This effect is often evident in emergency situations, such as the case mentioned, where Eleanor fell on the sidewalk and was ignored despite the clear need for assistance.
Similar examples of the bystander effect include not reporting an accident on the freeway, assuming someone else already has, or walking past someone in distress in a public space. The tendency to not intervene can also extend to less immediate scenarios, like cyberbullying or societal neglect, highlighting the impact of social situations on our actions.