Consent vs. Assent vs. Permission: What's the Difference and When to Use Each
By Dr. Zubair Khalid, DVM, MS, PhD ·
Quick Answer
- Consent is the informed, voluntary agreement of an adult with full decision-making capacity to participate in research.
- Assent is the affirmative agreement of a child or an adult with impaired capacity, obtained alongside the permission of a parent or legally authorized representative.
- Permission is the authorization given by a parent, guardian, or legally authorized representative for someone who cannot legally consent on their own behalf.
Understanding the Core Distinctions
The terms consent, assent, and permission are frequently used interchangeably in everyday conversation, but in research settings they carry distinct meanings with different legal and ethical implications. The distinctions matter because they determine who has the authority to agree to participation, what information must be provided, and how the agreement is documented. For researchers, using the wrong term can lead to improper enrollment, invalid consent processes, and potential harm to participants.
The fundamental principle underlying all three concepts is respect for persons, which requires that individuals be treated as autonomous agents and that those with diminished autonomy be protected. This principle is embedded in the ethical framework that guides research involving human subjects. The National Library of Medicine's Research Methods Resources provides access to authoritative biomedical texts that explain these foundational ethical requirements in detail.
Consent is the broadest and most rigorous standard. It requires that a person with full decision-making capacity voluntarily agrees to participate after receiving complete information about the research, including its purpose, procedures, risks, benefits, and alternatives. Consent is an ongoing process, not a one-time signature. The participant must be able to ask questions and withdraw at any time without penalty.
Assent applies specifically to children and to adults who cannot provide full legal consent due to cognitive impairment or other conditions. Assent is the affirmative agreement of the individual to participate, even though that individual lacks the legal authority to consent on their own behalf. The process must be developmentally appropriate, meaning the information is presented in a way the person can understand.
Permission is the authorization given by a parent, guardian, or legally authorized representative for a minor or an incapacitated adult to participate in research. Permission is a necessary condition for research involving these populations, but it is not sufficient on its own. The individual's assent must also be obtained whenever they are capable of providing it.
At a Glance
The following table provides a quick reference for when each term applies and what is required in practice.
| Term | Who Provides It | When It Applies | What It Requires |
|---|---|---|---|
| Consent | Adult with full decision-making capacity | All research involving competent adults | Voluntary agreement after full disclosure of risks, benefits, and alternatives |
| Assent | Child or adult with impaired capacity | Research involving minors or adults who cannot fully consent | Developmentally appropriate agreement, with the option to decline or withdraw |
| Permission | Parent, guardian, or legally authorized representative | Research involving minors or adults with impaired capacity | Authorization from a legally recognized authority, always paired with assent when possible |
The table above is a practical starting point, but the actual requirements vary by institution and by the specific research context. Institutional review boards (IRBs) have their own policies that must be followed. The EQUATOR Network provides reporting guidelines that help researchers document their consent and assent processes transparently, which is essential for ethical review and publication.
Why the Distinction Matters in Research
The distinction between consent, assent, and permission is not a matter of semantics. It reflects a fundamental ethical commitment to respecting the autonomy of research participants and protecting those who cannot protect themselves. When researchers confuse these terms, they risk obtaining authorization from the wrong person or failing to obtain the necessary agreement from the participant themselves.
For example, a researcher who obtains only parental permission for a study involving children has not fulfilled the ethical requirement to obtain the child's assent. Conversely, a researcher who obtains a child's assent but fails to obtain parental permission has not secured the legal authorization needed for the child to participate. Both situations are ethically problematic and could result in the research being rejected by an IRB or a journal.
The Committee on Publication Ethics Core Practices emphasize that ethical research conduct extends beyond data collection to include how research is reported and published. Proper consent and assent documentation is part of the ethical foundation that journals expect to see when research is submitted for publication. Researchers who cannot demonstrate that they obtained proper consent or assent may face difficulties in publishing their work.
The Legal and Ethical Basis
The legal basis for consent requirements comes from a long history of ethical codes and regulations that were developed in response to research abuses. The core principle is that no person should be subjected to research without their informed and voluntary agreement. For those who cannot provide such agreement, additional protections are required.
The ethical basis for assent is the recognition that even children and adults with impaired capacity have a degree of autonomy that should be respected. They should be given the opportunity to agree or decline to participate in a manner that is appropriate to their level of understanding. This is not a formality. A child who clearly does not want to participate should not be enrolled in research, even if the parent has given permission.
The National Institutes of Health Grants and Funding pages describe the expectations for researchers who receive federal funding, including the requirement to follow ethical standards for human subjects research. Researchers who are uncertain about the requirements for consent, assent, or permission should consult their institution's IRB and the relevant regulations before beginning their study.
When Consent Is Required
Consent is required when the research participant is an adult who has the capacity to make an informed decision about participation. This is the default standard for most research involving human subjects. The consent process must include several elements.
Elements of Informed Consent
The informed consent process must provide the participant with information about the purpose of the research, the procedures that will be performed, the expected duration of participation, the potential risks and discomforts, the potential benefits, and the alternatives to participation. The participant must be told that their participation is voluntary and that they can withdraw at any time without penalty.
The consent process must also provide the participant with the opportunity to ask questions and to have those questions answered. The participant must be given sufficient time to consider their decision, and the consent must be documented in a way that is appropriate for the research context.
The National Library of Medicine's Research Methods Resources provide detailed descriptions of the elements of informed consent and the circumstances under which consent may be waived or modified. Researchers should consult these resources to ensure that their consent procedures meet the expected standards.
When Consent Cannot Be Obtained
There are limited circumstances in which consent may be waived or modified. These circumstances are typically defined by federal regulations and institutional policies. For example, research that involves no more than minimal risk and that could not practically be conducted without a waiver of consent may be eligible for a waiver. However, these waivers are not automatic and must be approved by an IRB.
Researchers who believe that their study qualifies for a waiver of consent should consult their IRB before proceeding. The IRB will evaluate whether the waiver is appropriate based on the specific circumstances of the study.
When Assent Is Required
Assent is required when the research participant is a child or an adult who does not have the capacity to provide full consent. The requirement for assent is based on the recognition that these individuals have a degree of autonomy that should be respected, even though they cannot legally consent on their own behalf.
Assent for Children
For children, the assent process must be developmentally appropriate. A young child may be given a simple explanation of what will happen and asked if they are willing to participate. An older child or adolescent may be given a more detailed explanation and asked to sign an assent form.
The child's assent must be voluntary. The child should be given the opportunity to decline participation without any pressure from the researcher or the parent. If the child does not want to participate, their wishes should be respected, even if the parent has given permission.
Assent for Adults with Impaired Capacity
Adults with impaired capacity, such as those with cognitive impairments or certain medical conditions, may also be asked to provide assent. The process must be adapted to the individual's level of understanding. The researcher must assess the individual's capacity to understand the information and to make a decision about participation.
If the individual is not capable of providing assent, the researcher must rely on the permission of a legally authorized representative. However, the individual's wishes should still be respected to the extent possible. If the individual indicates that they do not want to participate, their wishes should be honored.
When Permission Is Required
Permission is required when the research participant is a minor or is an adult who lacks the capacity to consent. Permission is provided by a parent, guardian, or legally authorized representative.
Permission for Minors
For minors, permission must be obtained from at least one parent or guardian. The parent or guardian must be given the same information that would be provided to an adult participant, and they must make an informed decision about whether to allow the child to participate.
In some cases, the permission of both parents may be required. This depends on the nature of the research and the policies of the institution. For example, research that involves more than minimal risk may require the permission of both parents.
Permission for Adults with Impaired Capacity
For adults with impaired capacity, permission must be obtained from a legally authorized representative. The representative must be authorized to make decisions on behalf of the individual, and they must make an informed decision about participation.
The researcher must verify that the representative is legally authorized to provide permission. This may require documentation, such as a power of attorney or a court order.
The Relationship Between Assent and Permission
Assent and permission are not interchangeable. Both are required for research involving minors or adults with impaired capacity. The permission of the parent or representative is necessary to authorize participation, but the assent of the participant is necessary to respect their autonomy.
The relationship between assent and permission is often described as a dual requirement. The researcher must obtain both the permission of the parent or representative and the assent of the participant. If either is missing, the research should not proceed.
When Assent Is Not Required
There are some circumstances in which assent may not be required. For example, if the participant is a very young child who is not capable of understanding the research, the assent may not be feasible. In these cases, the permission of the parent or representative is sufficient.
However, the absence of assent does not mean that the child's wishes should be ignored. If the child indicates that they do not want to participate, their wishes should be respected to the extent possible.
Practical Steps for Researchers
Researchers who are planning a study that involves consent, assent, or permission should follow a systematic process to ensure that they are meeting the ethical and legal requirements.
Step 1: Determine the Participant Population
The first step is to determine whether the study will involve adults with full capacity, minors, or adults with impaired capacity. This determination will guide the consent process.
Step 2: Identify the Appropriate Authorization
For adults with full capacity, the researcher must obtain consent. For minors or adults with impaired capacity, the researcher must obtain permission from a parent or representative and assent from the participant.
Step 3: Develop the Consent and Assent Materials
The researcher must develop consent forms, assent forms, and permission forms that are appropriate for the participant population. The forms must be written in language that is understandable to the participant or the parent or representative.
Step 4: Obtain the Necessary Approvals
The researcher must submit the consent and assent materials to the IRB for approval before beginning the research. The IRB will review the materials to ensure that they meet the requirements.
Step 5: Conduct the Consent and Assent Process
The researcher must conduct the consent and assent process in a way that is respectful and informative. The participant or the parent or representative must be given the opportunity to ask questions and to make an informed decision.
Step 6: Document the Consent and Assent
The researcher must document the consent and assent process. This documentation should include the date, the person who provided the consent or assent, and the method of documentation.
Records and Measurements
Proper documentation of consent, assent, and permission is essential for the ethical conduct of research. The records should be maintained in a secure location and should be available for review by the IRB or other oversight bodies.
What to Record
The records should include the consent form, the assent form, and the permission form. The records should also include documentation of the consent process, such as the date and time of the consent discussion and the name of the person who conducted the discussion.
How to Store Records
The records should be stored in a secure location that is accessible only to the research team. The records should be retained for the period required by the institution and by applicable regulations.
How to Use Records
The records should be used to demonstrate that the consent, assent, and permission processes were conducted properly. The records may be reviewed by the IRB, by the sponsor, or by a regulatory body.
Common Failure Patterns
Researchers often make mistakes in the consent, assent, and permission process. Understanding these common failure patterns can help researchers avoid them.
Confusing Assent and Permission
One of the most common mistakes is to confuse assent and permission. A researcher may obtain permission from a parent but fail to obtain the child's assent. This is a violation of the ethical requirements.
Failing to Obtain Consent from the Correct Party
Another common mistake is to obtain consent from the wrong party. For example, a researcher may obtain consent from a parent for a study involving an adult with impaired capacity, when the consent should be obtained from the legally authorized representative.
Using Inappropriate Language
The consent and assent materials must be written in language that is understandable to the participant or the parent or representative. Using technical jargon or complex language can make it difficult for the participant to make an informed decision.
Failing to Document the Process
The consent and assent process must be documented. Failing to document the process can make it difficult to demonstrate that the requirements were met.
Limitations and Professional Escalation
The requirements for consent, assent, and permission are not uniform across all institutions and jurisdictions. Researchers must be aware of the specific requirements that apply to their research.
Institutional Policies
Each institution has its own policies for consent, assent, and permission. Researchers must be familiar with the policies of their institution and must follow them.
Jurisdiction-Specific Requirements
The requirements for consent, assent, and permission may vary by jurisdiction. Researchers must be aware of the requirements that apply to their research.
Professional Escalation
If a researcher is uncertain about the requirements for consent, assent, or permission, they should escalate the issue to their institution's IRB or to a research ethics expert. The IRB is the appropriate body to provide guidance on these issues.
The Role of the Institutional Review Board
The IRB is responsible for reviewing research to ensure that it meets the ethical requirements for consent, assent, and permission. The IRB will review the consent and assent materials and the consent process to ensure that they are appropriate.
The IRB Review Process
The IRB review process involves a review of the research protocol, the consent and assent materials, and the consent process. The IRB will evaluate whether the consent and assent process is appropriate for the participant population.
The IRB's Authority
The IRB has the authority to approve, require modifications, or disapprove research. The IRB may also require changes to the consent and assent materials or the consent process.
The Relationship Between Consent and Research Integrity
The proper handling of consent, assent, and permission is a key component of research integrity. Research that is conducted without proper consent is not ethical and may be considered misconduct.
The Role of the Committee on Publication Ethics
The Committee on Publication Ethics Core Practices describe the expectations for ethical research and publication. These practices include the requirement to obtain proper consent and to report the consent process transparently.
The Role of the EQUATOR Network
The EQUATOR Network provides reporting guidelines that help researchers report their research transparently. The guidelines include requirements for reporting the consent and assent process.
The Role of Data Management and Sharing
The consent process must also address the use of data. Participants must be informed about how their data will be used, stored, and shared. The consent process must be consistent with the data management and sharing requirements of the institution and the funder.
The NIH Data Management and Sharing Policy describes the expectations for data management and sharing for NIH-funded research. The policy requires that researchers plan for the management and sharing of data, and the consent process must be consistent with the data management plan.
The Role of Researcher Identity
The researcher's identity and record-keeping are also relevant to the consent process. The researcher must be able to demonstrate that they have the appropriate training and qualifications to conduct the research.
The ORCID for Researchers pages describe the importance of maintaining a researcher identity and record. The researcher's ORCID record can be used to document their training and qualifications.
Frequently Asked Questions
What is the difference between consent and assent?
Consent is the informed, voluntary agreement of an adult with full decision-making capacity. Assent is the affirmative agreement of a child or an adult with impaired capacity, obtained alongside the permission of a parent or legally authorized representative. Consent is legally binding, while assent is an ethical requirement that respects the individual's autonomy.
When is permission required in research?
Permission is required when the research participant is a minor or an adult who lacks the capacity to consent. Permission is provided by a parent, guardian, or legally authorized representative. It is always paired with assent when the participant is capable of providing it.
Can a parent's permission replace a child's assent?
No. Parental permission and child assent are separate requirements. A parent's permission authorizes the child's participation, but the child's assent respects the child's autonomy. If the child does not want to participate, their wishes should be respected even if the parent has given permission.
What happens if a researcher fails to obtain proper consent?
Failure to obtain proper consent, assent, or permission can result in the research being rejected by an IRB or a journal. It may also be considered research misconduct. The Committee on Publication Ethics Core Practices emphasize that ethical research conduct includes proper consent documentation.
How should consent and assent be documented?
Consent and assent should be documented with a signed form that includes the date, the person who provided the agreement, and the method of documentation. The records should be stored securely and retained for the period required by the institution and applicable regulations.
What is the role of the IRB in consent and assent?
The IRB reviews the research protocol, the consent and assent materials, and the consent process to ensure they are appropriate for the participant population. The IRB has the authority to approve, require modifications, or disapprove research.
What should a researcher do if they are uncertain about consent requirements?
If a researcher is uncertain about the requirements for consent, assent, or permission, they should consult their institution's IRB or a research ethics expert. The IRB is the appropriate body to provide guidance on these issues.
How does data management relate to consent?
The consent process must inform participants about how their data will be used, stored, and shared. The consent process must be consistent with the data management and sharing requirements of the institution and the funder. The NIH Data Management and Sharing Policy describes these expectations for NIH-funded research.
Using the Evidence
| Source | Best use in this topic | Important limitation |
|---|---|---|
| Research Methods Resources | official guidance | Check the linked page for current local requirements |
| EQUATOR Network | official guidance | Check the linked page for current local requirements |
| Core Practices | official guidance | Check the linked page for current local requirements |
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References and Further Reading
- Research Methods Resources. National Library of Medicine.
- EQUATOR Network. EQUATOR Network.
- Core Practices. Committee on Publication Ethics.
- NIH Grants and Funding. National Institutes of Health.
- ORCID for Researchers. ORCID.
- Data Management and Sharing Policy. National Institutes of Health.
- NCBI Literature Resources. National Center for Biotechnology Information.
- PubMed. National Library of Medicine.
This article is educational and does not replace institutional policy, professional advice, or applicable safety and regulatory requirements.