Observers' responses to the tragic murder of Kitty Genovese outside her New York apartment best illustrated

A) the bystander effect.
B) the mere exposure effect.
C) the social-responsibility norm.
D) social exchange theory.

Bystander Effect

A social psychological phenomenon in which individuals are less likely to offer help to a victim when other people are present.

Social-Responsibility Norm

An expectation that people will help those needing their help.

Kitty Genovese

A woman whose 1964 murder in New York City became a symbol of urban apathy, leading to research on the "bystander effect."