Answer: bystander effect or bystander apathy
Step-by-step explanation:
bystander effect, or bystander apathy, is a social psychological claim that individuals are less likely to offer help to a victim when other people are present; the greater the number of bystanders, the less likely it is that one of them will help.
Several factors contribute to the bystander effect, including ambiguity, group cohesiveness, and diffusion of responsibility that reinforces mutual denial of a situation's severity.