Paula was feeling sad, so she decided to go to a comedy club. After being around happy people for an hour, Paula left the club feeling much better. This is an example of:

The answer is mood linkage.

Explanation:

Mood linkage occurs when a person "absorbs" the mood in their current environment. For example, when attending a meeting with friends, it's likely that people will feel amused simply because the environment is fun. This can happen the other way around, too: negative environments might result in a bad mood.

The concept of mood linkage has been studied in relation to the workplace: a comfortable work environment results in more productive workers.

in 342 bc j._c. egypt fell into the hands of the persians, under the reign of nectanebo ii

greek city-states unite in a revolt against the persian empire at the beginning of the fifth century bc. j.-c  

from the year 660 or 659 bc ad, cyrus preached the revolt against the medes to deliver the persians.

the chair is the committee member from the majority party who has the most seniority. in the south carolina senate, the chair is the committee member from the majority party who has the most committee seniority.