Final answer:
The tragic murder of Kitty Genovese outside her New York apartment best illustrated the phenomenon of diffusion of responsibility.
Step-by-step explanation:
The tragic murder of Kitty Genovese outside her New York apartment best illustrated the phenomenon of diffusion of responsibility. According to social psychologists, diffusion of responsibility occurs when no one in a group takes action because the responsibility to help is spread throughout the group. In the case of Kitty Genovese's murder, there were many witnesses to the attack, but individuals assumed someone else had already called the police, leading to a lack of intervention.