Final answer:
Rachel's incorrect assumption about her roommate Berta's tidiness is an example of the Fundamental Attribution Error, a common error in social cognition.
Step-by-step explanation:
Rachel's assumption about her roommate Berta's character based on the disorganized state of their room, without knowing Berta's situation of taking finals and working extensively, demonstrates what is known as the Fundamental Attribution Error. This cognition error occurs when people underestimate situational influences and overestimate dispositional or internal factors in assessing others' behaviors. Clearly, Rachel has limited information about Berta's circumstances, which leads her to this incorrect conclusion. The Fundamental Attribution Error is a common phenomenon in social cognition and highlights the discrepancies in how we interpret our own behavior compared to that of others.