Final answer:
To demonstrate a reciprocal relationship between hormone X and anxiety, Dr. Benson needs to show that injecting the hormone induces anxiety, suggesting a causal link.
Step-by-step explanation:
To establish a reciprocal relationship between the elevation of hormone X and extreme anxiety, Dr. Benson needs to show that people experience anxiety when injected with hormone X. This would demonstrate that not only does anxiety elevate the levels of the hormone, but artificially increasing the hormone can induce the emotional state it's associated with, thus suggesting a causal relationship.Moreover,
Dr. Benson might look for evidence that blocking the binding sites of hormone X can lead to opposite emotional states, such as feelings of euphoria, and that these feelings can, in turn, decrease the levels of hormone X, supporting the bidirectional influence between the hormone and the emotional state.