Passage Summary: Some researchers look at how animals behave to gain insights into how human personalities are formed.

Reasoning: Psychologists study animal personalities as a means to better understand the development and structure of human personality.

Analysis: This is a Paradox question in an 'EXCEPT' format, meaning four options will explain why studying animals helps us understand humans, and one will not. The central tension is why one would look at a different species to understand our own. To resolve this, look for similarities in biological structures or the advantages of using animals, such as shorter lifespans that allow for multi-generational studies. The correct answer—the 'EXCEPT'—will likely be a statement that is irrelevant to the comparison or one that highlights a fundamental difference that makes the study useless.