A child observes another child acting unafraid in the presence of a stranger. Then, the observing child also stops acting afraid of the stranger. This is an example of:

Social Referencing

Explanation:

Social referencing is where the child takes signs and behavior from his surroundings, people or objects.

He then determines the appropriate actions and emotions that are in a specific setting or environment.

Children watch the actions of others and imitate their activities and practices.