<span>Common cause because it is joint interest </span>
The correct answer is "reciprocity."
Reciprocity signifies a mutual exchange in which both parties benefit. In this case, Maddie is one party, and her professor is the other party. Since Maddie is volunteering to work with participants in her professor's study, her professor is benefiting from this free work. To make this a reciprocal relationship, Maddie would then have to receive a benefit, such as extra credit on her grade.
Answer:
Research is an essential component of psychology and it is important psychologists conduct research. It gives them the ability to understand and describe various behavior mechanisms. Research done by psychologists is conducted to be able to study human emotions and our actions.
