Final answer:
Jessica attributes her happiness to Leslie due to the actor-observer bias, which leads her to credit Leslie's disposition rather than the actual situation, the comedic film, for her happiness.
Step-by-step explanation:
The phenomenon that explains Jessica attributing her happiness to Leslie after watching a comedic film is known as the actor-observer bias. This is because, as an observer, Jessica is attributing Leslie's actions (choosing the movie) to Leslie's dispositional characteristics (thoughtfulness, good taste, etc.) rather than the situational factor, which is the comedic film itself being entertaining.
The actor-observer bias is a psychological concept where people attribute their own behavior to situational factors while attributing others' behaviors to their dispositions, which can also be related to the fundamental attribution error, another concept where people tend to overemphasize personality traits and underestimate situational factors when explaining others' behavior.