Sometimes, particularly in behavioral research, investigators plan to withhold information about the real purpose of the research or even to give subjects false information about some aspect of the research. This means that the subject's consent may not be fully informed. For example, to discover whether certain kinds of background music are more distracting than others in a learning situation, an investigator might recruit subjects and explain that certain aspects of learning and memory are being studied. If the research is to be conducted, some of the consent requirements must be waived. Subjects would be told that they would be required to learn sets of words and then be tested on how well they remember those words, but they would be deceived about the purpose of the research and certain elements of the study design.

A contrasting example, much discussed in the literature, is the Milgram study of obedience. Subjects of this study were told that, as part of a learning study, they were to give electric shocks each time a "student" made an error in learning. Although they consented to participate in a study of learning, they were unwittingly involved in a study of their own obedience and willingness to inflict pain. Subjects were told about the true nature and purpose of the research after they had participated. This research has been criticized for the emotional stress it caused and the "inflicted insight" provided to the subjects about their own behavior (neither of which they had consented to). Although Milgram's follow-up studies indicated that few if any subjects reported that they had misgivings about participating in the research, many commentators argue that such deception is wrong per se.

IRBs reviewing research involving incomplete disclosure or outright deception must apply common sense and sensitivity to the problem. They must first decide whether the information to be withheld would influence the decision of prospective subjects about participating in the research. In the case of the research about the effects of background music on learning and memory, this determination would be relatively easy. IRB members might well disagree among themselves, however, about the Milgram study. (Scholars and commentators have disagreed about it for years.) According to the regulations, research should not be permitted at all if the risk to subjects is more than minimal and the subjects are not being informed of things they would consider material to a decision to participate.

In deciding whether to waive or alter consent requirements, IRBs must consider the risks to which subjects will be exposed. To receive a waiver of consent requirements, the study must present no more than minimal risk. Further, the waiver must not adversely affect the rights and welfare of subjects, and must be essential to the ability to carry out the research.

A final condition for waiving some or all of the elements of informed consent is that, whenever appropriate, subjects will be given additional pertinent information after they have participated in such a study. The IRB must decide if subjects should be debriefed either after participating in research unwittingly or after knowingly participating in research that involved some form of deception. It is clear that debriefing is appropriate when it contributes to the subject's welfare (i.e., when it corrects painful or stressful misperceptions, or when it reduces pain, stress, or anxiety concerning the subject's performance). There is greater uncertainty over whether it is appropriate to debrief subjects when such a debriefing could itself produce pain, stress, or anxiety (i.e., IRBs must be concerned with cases where debriefing subjects might harm them but failure to debrief subjects would wrong them).

Psychological Harms. Participation in research may result in undesired changes in thought processes and emotion (e.g., episodes of depression, confusion, or hallucination resulting from drugs, feelings of stress, guilt, and loss of self-esteem). These changes may be either transitory, recurrent, or permanent. Most psychological risks are minimal or transitory, but IRBs should be aware that some research has the potential for causing serious psychological harm.

Stress and feelings of guilt or embarrassment may arise simply from thinking or talking about one's own behavior or attitudes on sensitive topics such as drug use, sexual preferences, selfishness, and violence. These feelings may be aroused when the subject is being interviewed or filling out a questionnaire. Stress may also be induced when the researchers manipulate the subjects' environment - as when "emergencies" or fake "assaults" are staged to observe how passersby respond. More frequently, however, IRBs will confront the possibility of psychological harm when reviewing behavioral research that involves an element of deception, particularly if the deception includes false feedback to the subjects about their own performance. Some examples from the American Psychological Association's guidebook, Ethical Principles in the Conduct of Research with Human Subjects (1973), illustrate the kinds of research - and the types of psychological risks - IRBs may encounter:

• A social psychologist attached a psycho-galvanometer to subjects (male college students). The participants were told that the needle would be deflected if they were aroused, and that if the needle deflected when they viewed photographs of nude males, it would indicate latent homosexuality. Then false feedback was given so that the subjects were led to believe incorrectly that they were latent homosexuals. After the experiment, the ruse was explained.

• Students in a school of education were told by the experimenter that questionnaires revealed that they were unsuited for the teaching profession, although this was untrue. The expectation was that students with such evaluations would do poorly in their course work because these negative appraisals would lower their self-esteem. Many of the students were upset with the "results" of the questionnaire and considered abandoning the teaching profession.

• The work which seems to me to raise ethical questions of the most serious type occurred in a military setting. It involved taking untrained soldiers, disorienting them, placing them in an isolated situation, giving them false instructions, and leading them, as individuals, to believe that they had caused artillery to fire on their own troops and that heavy casualties had occurred. The subjects ran, cried, and behaved in what they could only consider an unsoldierly way, and no amount of debriefing could remove the knowledge that they had done so.