Answer:
Cognitive dissonance
Step-by-step explanation:
In psychology, the term cognitive dissonance refers to the mental discomfort experienced by a person who holds contradictory beliefs, ideas, or values.
This discomfort is triggered by a situation in which a person's belief is contradicted by new evidence perceived by the person so the person will try to find a way to resolve the contradiction to reduce their discomfort.
In this example, Sonya thought sororities were filled with snobs, however during her first week in campus she was approached by a sorority member who invited her to a social function.
We can see that Sonya's beliefs about sororities were contradicted by the new evidence she perceived when she attended the social function, this made her feel cognitive dissonance and her way to resolve the contradiction was to conclude that sororities do a lot of good things for the community.
Thus, Sonya's change in attitude to match her behavior relates to cognitive dissonance.