Freely given informed consent is regarded as one of the most central requirements for research on humans where the research entails recording of data and/or any kind of discomfort, inconvenience or risk to the subjects of the research. Research must not be carried out on individuals or groups without their express permission. The requirement that the consent be freely given and informed means that the subjects must not be under any kind of pressure when they give their consent ("freely given" or "voluntary"), and that their consent must be based on knowledge of the research to be conducted ("informed").

The importance of freely given informed consent

Some of the emphasis on freely given informed consent in today's research ethics is a response to the medical research that was conducted on prisoners against their will during World War II. Some of this research cost a great many lives, and was described in the Nurnberg Trials as crimes against humanity. It is accordingly reasonable to intensify the requirements set for (reflection surrounding) freely given informed consent in connection with research on particularly exposed or vulnerable groups, and if the research entails any kind of risk or sensitive information (see Confidentiality).

Although freely given informed consent is by no means a sufficient condition for research on humans, it is reasonable to say that it is a necessary condition at the outset, in cases where there is a possibility of the research entailing some type of risk or discomfort for those on whom the research is being conducted. But even here the answer is not always a given: The type of research (biographical research? registry research? drug trials?), the nature of the information (sensitive information? implications for third persons?), the purpose of the research and the probability of success are some of the variables that are relevant in an ethical assessment.

The requirement of informed consent is grounded in respect for the individual, and treating people as autonomous subjects is a fundamental aspect of this respect. This means that their own wishes and perceptions must not be ignored in the name of science, no matter how great the benefits expected to be yielded by the research. Special considerations and measures are required for persons who cannot be regarded as fully autonomous individuals (see Reduced capacity to consent).

Informed consent will also be of great importance in the best interests of the research itself. Research where this requirement is not respected will lose trust and respect and accordingly loss of repute.

"Freely given"

That the consent must be voluntary or freely given means that research subjects must not arrive at their position through a process characterised by coercion or pressure. An unacceptable weakening of this requirement may also be inherent in some situations that do not involve any direct coercion. In many connections, being a researcher imparts an authority that stems from a general respect for science; and even though this is a legitimate enough position, it is important to be aware that this authority confers a power that influences people's decisions beyond, for example, reasonable ideas of the value of the specific project. This does not only apply to the initial consent; it may also cause some subjects to hesitate to withdraw from a research project even when, for example, they find that the risk or discomfort exceeds what they had been prepared to tolerate.
Other factors may also complicate the picture. For example, situations may arise where it is known that persons with a standing in a community consent, and this in turn may be experienced by others, particularly young people, as inhibiting their freedom to make their own choice. This may happen even though the researcher applies no pressure.

Another issue in this connection is the use of incentives. In some situations, remuneration to informants or research subjects may be regarded as a means of applying pressure. It may therefore be important to distinguish between reasonable and unreasonable influence. People in a precarious financial situation may consent to research that they would not otherwise have taken part in because they need the money. This may present its own challenges, not least in connection with research on persons in impoverished regions/countries.

Conversely, there are arguments to the effect that in many cases offers of money or other goods are not only acceptable, but reasonable compensation for people's time having been taken up in the pursuit of research. The compensation is then understood as an acknowledgement of the other's input. A related form of offer of money or the equivalent to research subjects that is often the least problematic is compensation for the direct expenses incurred by the person concerned in connection with participation (appropriate transport to and from the site, for example).

In some connections, a fee can also help to keep the relationship between researcher and informant/subject clear. It is not always equally obvious to non-researchers where the line is drawn between interaction in the interests of research and the start of a more personal/friendly relationship, with the demands and complications that may entail. (At times it may also be difficult for the researcher). A financial transaction can serve to make the relationship a professional one.

More generally, in order for a consent to be free it is also important for the researcher to make a point, where relevant, of explaining the relationship of the research with other groups. Research subjects may feel themselves to be more or less dependent on, subordinate to or vulnerable in relation to certain other players or units. This makes it important for the researchers to provide information about the relationship of the researchers and the project with these groups. Research on young people, convicts or illegal immigrants ought, for example, not to take place without explaining to the group in question relationships with power factors in their lives such as teachers, school boards, prison boards of governors and the police. This naturally applies in particular when researchers use these authorities as a means to come into contact with the group on which they wish to conduct research. For non-researchers, the relationship between the researcher and the surrounding apparatus is often not clear at the outset.

One aspect of voluntariness is that research participants must know that they can withdraw from participation at any time during the project without owing any explanation for doing so.


The requirement that the consent must be informed means that research subjects must not be ignorant of the research project's methodology/procedures, purpose, type of results expected and planned dissemination. It is also reasonable to provide information about relevant interest groups (not least: where does the research funding come from?) The information that must be provided naturally also include what is known with regard to expected inconvenience, discomfort and risks to the research subject.

Full information will normally be unachievable, for several reasons. Providing full details would demand an enormous amount of time and resources; taken to the extreme, an absolute requirement of insight would mean that research subjects must themselves be researchers. (The logical extreme would be that historians could only conduct research on historians, psychologists only on psychologists etc.) Furthermore, the very nature of research means that not everything will be known in advance; this means that information will often be in terms of probabilities. It will also often be reasonable to provide more information along the way, as it becomes available to the researcher herself, so that the research subject has the option of withdrawing freely should relevant changes occur. Finally, special caution is required if research is to take place on persons who cannot reasonably be expected to be capable of grasping what the information implies, whether these persons be children, dementia patients or cultures without an established scientific concept they can relate to.

Thus a key word with respect to the requirement that consent be informed is "sufficient(ly)". What being sufficiently informed means is has to be assessed on a case to case basis. A rule of thumb in the face of some of these challenges is that the research subjects must have information from which nothing has been excluded that could reasonably be expected to alter their consent. Even this rule has its exceptions, however; for example, when it has been concluded on ethically justifiable grounds that deception as a research method is acceptable.


The consent obtained must be explicit. It must also be clear and unambiguous, with as little room as possible for conflicting interpretations. Where possible, this also means that in most cases the consent should be written (important exceptions can be made for research on groups that do not have reading and writing skills, or research on vulnerable groups in war or war-like situations where collecting lists of names is not always advisable). It is normally essential for consent to be obtained in advance, i.e. before the research commences, and that in projects where this is relevant, consent is viewed as something to be renewed or updated along the way.
Although it may be tempting in view of the desire to include persons with the least possible resistance, researchers should guard themselves well against promising "too much" or skimming lightly over questions or objections regarding, for example, the results or the dissemination of the research project. Not only does this put one in a grey area where one risks deceiving people; for purely pragmatic reasons, expectations that prove not to be satisfied will backfire on the researcher at some point or another.

This article has been translated from Norwegian by Beverley Wahl, Akasie språktjenester AS.