Researchers sometimes deceive participants in psychological research and experiments on methodological grounds. There are two main objections to methodological deception, related to the risk of causing psychological harm to research participants and violating their autonomy. In my opinion, methods of deception can be used in psychological research without causing significant harm and without violating autonomy. Firstly, deceptive methods seem to be the only means by which both individuals and society can obtain important information about certain psychological tendencies: such information can greatly value society. Knowledge of discriminatory tendencies, for example, can be used to build a more efficient and just society. Secondly, since research participants are interested in training their ability to be autonomous agents in making decisions and appropriately controlling their behavior, they are also interested in learning about their unconscious psychological tendencies, even if such information may cause minor stress in some circumstances. Current professional codes of ethics are designed to prevent psychological experiments using deception where they are likely to cause serious psychological harm to research participants.
Experiments carried out by existing norms can, in some circumstances, cause minor stress, but I believe that the mere possibility of such stress does not show that experiments are morally unacceptable. If I were to participate in research based on deception, I would accept it as a necessity for good results. Before agreeing to conduct a study, a person must independently be aware of stress risks. The fact that participants in deception studies confirm what they know about the purpose of the study is quite logical. All participants in the experiment should be informed about all important steps. People who agree to participate in psychological research must decide whether the risks are worth the research goal.