Final answer:
Maria's elation from acing her midterm exams influencing her roommate's mood is an example of emotional contagion, where one person's emotions affect another's.
Step-by-step explanation:
The situation described where Maria's elation from her midterm exams positively affects her roommate is an example of emotional contagion. Emotional contagion is the phenomenon where one person's emotions and related behaviors directly trigger similar emotions and behaviors in other people. When Maria comes home feeling elated, it's likely that her positive emotions and expressions are observed by her roommate, who then experiences an uplift in mood. The cheerful demeanor of one individual can nonverbally influence and change the affective state of others around them.