Author: Dr. Ann Hardy and Dr. Sherry Mills
Date: June 7, 2023


The federal regulations for the protection of human subjects in research, also known as the Common Rule, require that informed consent of potential research participants present adequate information to allow them to understand why they might or might not want to participate in the research, including details about the purpose of the research and the procedures to be followed (45 CFR 46.116 ).


But what if an investigator has legitimate concerns that providing a full description of the research may bias the outcomes? For example, consider a study to explore the impact of interviewer characteristics on survey responses or another in which study staff play the role of other participants to study how interactions with others may impact research outcomes. Full disclosure of these procedures in advance of the research could likely influence the behavior of participants. While deception is more commonly associated with social, behavioral, educational research (SBER), it has also been used in clinical research. But is it permissible to deceive participants about certain aspects of the research?


There are several well-known studies that used deception in ways that are now recognized to be unethical, including:

– The Tuskegee study (1), which ran from 1932-1972, involved several unethical practices including deceiving participants about the disease being studied (syphilis) and telling them they were receiving treatment when they were not.

– The 1963 Milgram study of obedience (2) in which participants were instructed to give electric shocks of increasing voltage when learners made a mistake in a word pairing test. There was no shock delivered and the learners were study staff who acted out increasing levels of distress upon receipt of the shocks. Participants were repeatedly urged to continue, and many suffered severe emotional distress from believing they were harming the learner, including physical manifestations like shaking, stuttering, and in a few cases, seizures.

– A cervical screening and cancer study conducted in New Zealand (3) was designed by an investigator who did not agree with standard medical recommendations regarding the removal of the early-stage cervical cancer lesions by biopsy as the best way to prevent progression to more invasive forms of the disease. This investigator, with the approval of his hospital, did not offer the patients in his study the standard biopsy treatment but instead told them they would be managed by on-going follow-up with repeated Pap testing. Despite the recognition in many countries of disease progression and increased deaths in untreated early-stage cases, including for patients in this study, this research project continued from 1966-1987.


Despite these examples of unethical participant deception in research, deception in research may be permitted under current regulations and guidelines in very specific circumstances.


How is deception currently used in research?

There are two main ways in which investigators currently use deception in research:

– Incomplete disclosure is where the exact purpose of the research or certain aspects are withheld from potential participants. For example, participants are told the study involves completing routine cognitive tasks but does not tell them that the environmental conditions, such as room temperature or background noise, will be purposely manipulated.

– Participants are given false information. For example, a research staff member posing as another participant tells participants a made-up narrative to note participants’ reactions or impact on subsequent research tasks.


Regulations and Guidance for Deception in Research:

– Federal regulations: While the federal protection of human subjects regulations do not specifically address deception in research, the regulations (45 CFR 46.116(f)) do permit waiver or alteration of elements of consent for research:

  • That is no greater than minimal risk.
  • That could not otherwise practicably be conducted.
  • Where the waiver or alteration will not adversely affect subjects’ right and welfare.
  • In which subjects are provided with additional information after participation when appropriate.

– The American Psychological Association addresses deception in research in their published Ethical Principles of Psychologists and Code of Conduct, Standard 8.07 and 8.08; ( These standards emphasize the scientific need for deception, limitations for use in riskier research, and the need for debriefing.

– Most IRBs, academic institutions and other entities conducting research have specific guidelines for the use of deception in research so investigators should check with their IRB and institutions early in the study design phase.


Main Considerations for Investigators in Using Deception in Human Subjects Research:


1. Your study should be making a notable contribution to a scientific field.

2. There should be a clear scientific justification of the need for the deception to protect the scientific integrity of a study and without an effective or scientifically sound alternative to conduct the research without deception.

3. IRBs will generally not approve studies that include deception for studies that are greater than minimal risk.

4. Even in minimal risk studies, participants generally should not be deceived about aspects of the study that are associated with risk of physical harm or emotional distress.

5. For deceptive research practices in studies involving vulnerable participants, consult with your IRB about whether and how these may be conducted.

6. Debriefing of subjects at the end of their participation is generally required to explain the deception, including why it was needed, and to allow them to withdraw from the study if they wish.



1. Fairchild, A.L. and Bayer, R. 1999. Uses and Abuses of Tuskegee. Science 1284 (5416): 919-921.

2. Mcleod, S. The Milgram Shock Experiment: Summary, Results, and Ethics. Simply Psychology. Updated May 10. 2023.

3. Coney, S. and Bunkle, P. An Unfortunate Experiment at National Women’s. Metro. Auckland, June 1987: 47-65.


Other Posts