Answer:
The answer is pluralistic ignorance.
Step-by-step explanation:
Pluralistic ignorance is a social phenomenon in which people comply to a social norm because others seem to accept it. It has been linked to the bystander effect, the phenomenon shown in this example, in which a person does not take action after seeing no-one else is acting. The person will probably assume that, because no-one else is acting, any action would be unacceptable.