Intellectual impairment

‘Intellectual disability’ is the term used when referring to the diagnosis. The term ‘intellectually disabled’ is used when referring to a person or persons with the diagnosis. Recent Norwegian research and statistics on intellectual disability as a phenomenon and on persons with intellectual disabilities, is relatively limited. However, there has been major social change, a great deal of new knowledge in a variety of disciplines and considerable changes in the general living conditions of the Norwegian population. The research that does exist is largely made up of small studies with limited samples.

Introductory figures

According to official figures from the Norwegian Directorate of Health, 21 000 persons in Norway have an intellectual disability. Intellectual disability relates particularly to cognitive impairment, and is graded as mild, moderate, severe or profound. The figure is based on what is referred to as an administrative prevalence, and consists of persons registered with the diagnosis intellectually disabled who are users of municipal health care services in Norway. The official figure is considered to be considerably lower than the actual prevalence.

Voluntary informed consent

One of the conditions for including someone in a research study is that, as a general rule, voluntary informed consent has been obtained. Studies involving subjects who are unable to give voluntary informed consent require such consent to be obtained from someone who can do it on the person's behalf, and who has the authority to do so. Such studies require particularly rigorous scientific and ethical evaluations before they are approved, and relatively few studies of this kind are carried out. The most common type involves minors, where the matter of authority and consent is relatively clear.

From a research perspective, it can be challenging when a large number of participants drop out of studies, and particularly when drop-out is systematic and skewed. It is important to know the cause of such drop-outs. If they are due to lack of consent, and if this concerns large parts of the population that are particularly sought after in the research, drop-out becomes a major weakness of the study. Persons with intellectual disabilities find it difficult, in some cases, to give voluntary informed consent. This is partly due to the actual disability, the cognitive functioning, but also to the information about what is to be studied and how. This in turn affects the assessment of the person's competence to give consent, although this is also an independent requirement. The researcher and the research find themselves facing what at times can be a clash of interests between meeting the requirement for voluntary informed consent and the consequences of a large percentage of people with intellectual disabilities dropping out of important studies. The latter is further exacerbated by the fact that the drop-out rate increases with the degree of cognitive impairment. Because research is important to and influences the shaping of society and the formulation of public services, it is important to include and involve as many people as possible in the research. Systematic drop-out not only represents a methodological issue, but also raises questions about research ethics.

All three elements of the term "voluntary informed consent" should be met when respondents are recruited for research projects. Each of the elements entails a number of challenges.

The voluntary aspect

Many of those with intellectual disabilities have a difficult relationship with the concept of 'voluntary'. Many perceive that respect for their free will in everyday activities is too variable. The cognitive impairment means that some people feel they are being 'manipulated' in the sense that they are being persuaded or convinced by those who are better able to put their argument across, both linguistically and in terms of reasoning. In Denmark, the National Association of People with Learning Disabilities (ULF) says that many of those with intellectual disabilities have a strong belief in authority (National Institute on Intellectual Disability and Community (NAKU), 2007). This means specifically that they are unable to set boundaries for what they want to participate in. Many, not all, with an intellectual disability can have a tendency to just agree with what is being said to them, with the result that their consent is assumed to be given.

It must also be stressed that it can be just as detrimental to question the free will behind consent given. If the person wishes to participate in a study, and this is withdrawn or prevented, it may also be because the person feels pressured or threatened into not participating.


Information is about several things. It is partly about acquiring knowledge, or being informed. Even more importantly, it's about the information being understandable. Information presented in a way that makes it understandable for some but not for others may have a repressive and stigmatizing effect. Many people with intellectual disabilities cannot read, even if the text is an Easy Read text. (Easy Read: a special way of writing developed to make text easier to read. For example, compound words are broken down into single words to make them easier to understand.) It is also not necessarily the case that a text written or presented understandably purely in terms of concepts is meaningful. In order for consent to be regarded as informed, it is essential that the actual content or meaning of the information is understood.

In a research context, this means that for the consent to be informed, the participants must also understand the presentation of the research project, i.e. what it intends to deal with, what it is seeking to find answers to, what the research will be used for, and what role the participant will play in this. Thus, it goes without saying that the farther removed the research is from the person's everyday life and experiences, the more difficult they will find it to understand what the research is all about. As is the case for everyone, and even more so for those with intellectual disabilities, experiences that are recent or well-remembered and clear are easier to discuss and have opinions about than complex, hypothetical and theoretical matters and phenomena. In other words, consenting to voluntary participation, and claiming to understand that there is an option to say no or to withdraw at any time, is not enough for the consent to be called informed.


To 'consent' to something means, in simple terms, that a person is willing to do something. As the term is used here, however, it is more of a legal term. Competence to give consent consists of several elements. It is partly about who has the right to consent. It is partly related to age (persons of legal age), what consent is being given for (treatment, financial arrangements etc.) and whether the person is actually capable of knowing the difference between saying yes and no. Consent and competence to give consent are referred to in various legal texts, including the Patients' Rights Act (Pasientrettighetsloven). Assessing who is competent to give consent with respect to medical treatment is determined by the person responsible for the treatment. The Act states that individuals with "mental retardation" (definition given in ICD-10; The International Statistical Classification of Diseases and Related Health Problems) may lack competence to give consent in connection with health care and medical treatment. Competence to give consent is of course related to what the consent is being given for, and is not just based on assessments of the person's abilities. Consequently, whether a person is competent to give consent is not something that applies once and for all and in all situations.


Anonymization of the subjects is a requirement that is often imposed in research. (See also The Personal Data Act.) However, ensuring anonymity is not always easy. There will also be some situations where the requirement for anonymity is especially important. Research that uncovers controversial findings or violations of regulations can have unforeseen consequences for the person who provided the information if their identity becomes known. Information may also come to light which, in itself, or in combination with other information, can put the person supplying the information in a compromising position. Nor does the public have the right to know anything about an individual's diagnoses, state of health, family circumstances etc. Some people are not always aware that they give away information when talking with others. Those with a cognitive impairment may be less aware of how the information they provide can be used. Some have suffered the consequences of this, and as a result have learned to keep quiet about matters that they might be better raising with someone else. If the research concerns people in vulnerable situations, failure to meet the requirement for anonymity can have adverse and critical consequences. Something similar also happens when relatives of a service user say that they would rather avoid criticizing staff or a service for fear that this may have repercussions for the child. If the scope of respondents, particularly small samples in a very limited geographical area, or specific characteristics of individual respondents can help reveal who they are despite attempts at anonymity, there is reason to be extra critical of the research design.

The researcher may also find that subjects disclose information, either to the media and in public, or more privately, by telling others about what they have participated in. Persons with intellectual disabilities often encounter many public sector employees, representatives from the health and care professions, and this in turn may lead to people obtaining information that makes it possible to link anonymized research data to participants. This requires special care by the researcher, and means that anonymization alone does not safeguard the participants' right to anonymity.

Method-specific ethical problems

Choice of research design and methodology is normally based on which issues the researcher wants to shed light on, or the research question they pose. Among the methodological considerations faced by the researcher is whether the method and the research design chosen entail special ethical challenges. Here it may be necessary to consider the choice of method, and thus which questions can be answered, in light of the considerations mentioned above. The following are examples of this research ethics dimension.


Surveys are a useful and effective way of collecting certain data. They often use a relatively large sample, and anonymity is often well protected. Some conditions apply, of course, including measures to prevent personal registers being linked to the actual data. If the survey consists of easy questions about everyday matters, and the purpose of the survey is to provide simple overviews, many will also be able to give voluntary informed consent, including those with intellectual disabilities. Where surveys are more targeted and issues raised relate to complex matters, voluntary informed consent will be harder to obtain in general, and especially for those with intellectual disabilities. In addition, many will find it difficult to respond in writing to written questions. If these respondents need assistance from those around them to answer questions, the principle of anonymity is weakened, and other methodological problems arise. It is important to emphasize that people with intellectual disabilities can, and have, participated in such surveys. It is also desirable that these types of surveys are conducted in such a way that people with intellectual disabilities can be included.


Interviews by their very nature entail greater exposure, particularly when the interview entails a physical presence (as opposed to telephone interviews, for instance). The interviewer's conduct/behaviour influences the participant in both of these methods, but perhaps more so where there is physical proximity. The interview effect is well known in general, but it is important to be aware that people with intellectual disabilities may have a learning background that has resulted in an inferiority complex or a strong belief in authority, which makes many try extra hard to provide the answers that they think the interviewer wants. It is also important to be open to the possibility that, in such cases, the relationship of power between the interviewer and the interviewee may be more asymmetrical than the interviewer imagines.

Interviews present various opportunities to ensure that the information is provided in a comprehensible manner, and that clarifying questions can be asked, with the possibility for supplementary explanations. Thus, the potential for obtaining informed consent is strengthened. At the same time, there is the risk that the degree of perceived free will is weakened. For instance, it is conceivable that participants who find questions in a questionnaire to be too private, strange, irrelevant or uninteresting etc., might not complete the form. This is not possible when the interviewer is actually sitting holding the form or leading the interview. It is also more difficult to withdraw from something one has agreed to take part in. In situations where subjects generally might opt not to answer, this will not happen to the same degree when people with intellectual disabilities are asked questions.


Studies based on observation, often participatory observation, are often used in studies of people with intellectual disabilities. In such studies, the researcher and the participants are in a situation where it can be difficult to predict what information might be given. Although the researcher has formulated a specific research question, information may be given that the researcher could not have foreseen. This has a bearing on how informed the consent can be with respect to participation in observational studies, and requires strict requirements for anonymity and ethical sensitivity. There needs to be an agreement not to disclose or expose information from the observations that is extraneous to the original purpose of the study. The observer may obtain information about matters that it is unlikely that consent would be given to collect information about if they were described in the project outline. In the same way, it will be possible to observe persons who have not given their consent since they are to be regarded as third parties. In principle, it is the nature of research to seek knowledge and insight into factors that might have a bearing on the research questions posed. Research ethics, for their part, set boundaries that may imply restrictions on what and where the researcher can observe in the project in question.

End notes

As can be seen, there are research ethics considerations that have their origin in very general principles, and which are amplified or influenced by the actual impairment of persons with intellectual disabilities. This must be taken into account in the ethical considerations in research projects involving people with intellectual disabilities. It is also important that researchers exercise a particular ethical sensibility when presenting and disseminating research findings in order to ensure that the appropriate considerations are made. The example of anonymizing data has already been discussed, but here we also consider how people with intellectual disabilities are portrayed, and what impression is formed (norms and stigmas).

It is equally important that academic communities, research programmes, research ethics committees etc. review and discuss matters that impede or prevent the carrying out of useful and necessary research that concerns persons with intellectual disabilities. If the current arrangements for obtaining approval for research involving persons without the competence to give consent are so complicated or rigid that such research is avoided, this in itself is a research ethics dilemma that needs to be resolved. It could conceivably lead to researchers trying to adapt the research projects to the requirements that are easiest to fulfil. This might, for example, take the form of omitting the people without the competency to give consent from the project, or changing the research topic so that these people are not central contributors. Such a solution entails circumventing some ethical problems, but other equally important research ethics problems arise at the other end. Systematic selection of parts of the population not only weakens the research but is also, in itself, a research ethics problem. It is equally important to ensure that no one with intellectual disabilities is denied the right to participate in surveys, whether due to a desire to protect the individual, cover up facts and events, or prevent disclosure of the reality experienced by persons with intellectual disabilities.

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