In psychological research, deception occurs when participants are wrongly informed or misled about the aims of the experiment. The participants may be deceived about the setting, purpose or design of the research.
Despite the fact that deception is permitted by the American Psychological Association, whether or not deception should be used when conducting psychological research experiments has been the subject of numerous debates.
Psychologists who are against deception argue that misleading participants in a research experiment is dishonest and makes the participants feel clueless about the nature of the research. Psychologists in favor of deception are of the opinion that it is sometimes necessary in order to avoid demand characteristics by allowing the participants to actively engage in the experiment without behaving in an unnatural way.
A psychologist should not conduct any studies involving deception unless the use of the deceptive techniques has been predetermined and is justified by the experiment's prospective educational or scientific value. Psychologists are also not allowed to use deception if the deceptive technique will cause the participant emotional distress or physical pain. If deception is used, the psychologist must explain it to the participants as early as possible, ideally immediately they complete their participation, in order to allow participants to withdraw their data.