Answer:
Attribution effect or the fundamental attribution error
Step-by-step explanation:
Attribution Effect:
In social psychology, attribution effect, also referred as fundamental attribution error explains the tendency for people to under-emphasize the influence of the external factors for the observed behavior of a person like situational explanations of others behavior while over-emphasizing on the internal, based on personality and dispositional explanations instead.
This is a self serving bias. Thus Cheryl attributes her bad grade to the situation while that of her co-worker on the personality trait of her.