Brittany cannot remember what happened during her psychology class and suggests that aliens from outer space temporarily kidnapped her brain. Her roommate suggests that she slept through class. Most psychologists prefer the "sleep" explanation because it is more:

Parsimonious

Explanation:

Parsimony, to understand it first of all we have to know what is the meaning of these words. This is a word that is used in the late middle age of literature in English. It is an extreme thriftiness economy and frugality. This is the word that means in psychology to an accurate explanation about the cognitive process and the behavior of a person.

We all know that our brain is a complex procedure but we can not make our understanding so complex. Many of the psychologists make it so simple and understandable and unsupported assumptions. So that most of the psychologist prefer parsimonious.