Research involving people carries a profound responsibility. As a researcher, you are the first line of protection for your participants. That means you must understand not only when consent is required, but also when assent is needed, when both are necessary, and when one may be impossible to obtain. Getting this wrong can compromise research integrity, expose institutions to reputational damage and legal consequences, and most importantly, put participants at risk. Getting it right is part of being a responsible researcher. 

As a researcher, you are probably already familiar with the concept of Ethics Approval if you work with human participants, tissue or data in any way. In brief, ethics approval is a formal review conducted by an Ethics Committee, which evaluates the risks and benefits of a study and makes a decision as to whether it can proceed. Any manuscript derived from research involving human participants, human data, or human biological material must have this. In addition, those contributing their experiences, data or bodies must agree to do so. This is where it gets a little less black and white. For example, who gives consent to participate if the person participating doesn’t have the capacity to actively consent to you? This is where assent and consent come into play.  

Consent is the process by which a person who is legally able to decide for themselves voluntarily agrees to participate in research after being fully informed. When the participant is a minor, or incapable of providing consent for another reason (such as temporary or permanent impairment) a parent, legal guardian or responsible family member must provide this consent on their behalf. Assent, on the other hand, is the affirmative agreement of someone who cannot legally provide consent but is still capable of understanding what is happening and agrees to participate. Assent does not replace consent; it complements it. For instance, the participation of minors in a given study requires both parental consent and the child’s assent, unless a justified exemption exists.  

Seems simple, right? Unfortunately, some cases will require you to put your most effective “thinking hat” on and make the best call you can. Test yourself with the following scenarios.  

Out of the following scenarios, which ones require both assent and assent? Select all that apply.  

A: You are interviewing 14‑year‑old students about study habits. The students “agreed to participate,” but no parental consent is mentioned. 
B: You are conducting research involving unconscious hospital patients. Medical records are analysed retrospectively. You state consent was “not feasible,” but ethics approval and a consent waiver was granted. 
C: You are conducting focus groups with recently resettled refugees. Interpreters were used; participants consented, but comprehension is not described. 
D: You are leading interviews with adults with cognitive impairments. Participants are capable of basic understanding but lack full legal capacity. 
E: Use of tissue from deceased individuals. You are analysing stored biological samples from deceased patients. 

[image: researchers are grouped around computer screens with notepads] 

The correct answers are A and D! In the case regarding student participation you will need both assent (from the students) and consent (from the parents/legal guardians). A 14‑year‑old can understand the study and provide assent but cannot legally consent. Without parental consent, participation is not ethically valid. 

The case involving adults with cognitive impairments is also a classic case where both are needed. Even if someone cannot legally consent, their willingness (or unwillingness) must be respected. Therefore, you should aim to receive assent from the participant, and consent from the legal guardian or representative. 

Let’s review the cases that do not need both.  

• B (unconscious hospital patients): Whilst there is no need for assent, since the patient is unconscious and is not capable of giving it, consent from a legal representative is still needed unless a formal ethics waiver is granted. In this case, the waiver may be appropriate, but researchers must clearly document the ethics approval, including the committee name and reference number. 

• C (refugees): In this case, assent is not needed since adults can legally consent for themselves. However, refugees may face language barriers, trauma, or perceived power imbalances. Consent is only valid if participants truly understand what they are agreeing to. Therefore, in this case, the best practice would be to ensure comprehension.  

• E (deceased individuals): It's a researcher's responsibility to verify local regulations and ethics board requirements. This type of case usually involves stored tissues, and informed consent would have been required to take samples and archive them. However, after that point ethics approval is usually all that is required to use the stored samples.  

Hopefully these scenarios help you gain a better understanding of the differences between assent and consent. Generally, consent is almost always required when adult human participants are involved, and is usually sufficient on its own, as long as true comprehension is ensured. However, there are cases where consent is not sufficient on its own and must be complemented with either assent (e.g. when minors or adults with impaired capacity are involved) or an ethics approval waiver in the cases where assent is impossible (e.g. deceased patients). On the other hand, ethics approval is always required when human participants, data, or biological material are involved. Every manuscript must clearly state: 

• The name of the ethics committee 

• The approval reference number 

• Any waivers or exemptions granted 

Finally, remember that, as a researcher, your responsibility is both procedural and most importantly ethical. Ultimately, understanding the difference between assent and consent protects your participants, your research integrity, your institution’s reputation, and the credibility of your findings.  

If you need more information on Research Ethics, we have courses for Editors which are also free for researchers to take (just register with your email address): 

• Ethics Approval 

• Informed Consent 

• Animal Ethics 

• Ethics of Internet Research  

• Trial Registration