Which of these is an essential concern regarding ethical principles for human research?

A) Research participants must give informed consent.
B) Research participants must be deceived so that they do not know the true nature of the research to which they are contributing.
C) Research participants must be paid for their contribution.
D) As long as informed consent has been given, research participants may be subjected to any level of physical or psychological pain or discomfort.

Answer: A
Rationale: Participants in psychological research must give informed consent (i.e., they must be told about the purpose, tasks, and any risks, and then consent to participate). This does not mean that informed consent allows researchers to do anything they want.