Answer:The ceiling effect
Explanation:The ceiling effect refers to a situation in which an independent
variable (variable which is manipulated during an experiment) does no longer have an affect on a dependent variable (measured variable) This means a researcher can no longer count on his or her treatment as a cause of the results of what s(he) observing
"She finds that a vast majority of her participants, regardless of group assignment, are rated as very aggressive." The most of them acted agressive irrespective of group assignment. This means exposure to the violent movies was no longer an effect for the violence.